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• Joseph Thomas

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User’s guide

November 2011

Tunnels Study Centre www.cetu.developpement-durable.gouv.fr

Software

CAMATT 2.20 User’s guide

November 2011

WARNING This software has been developed through research conducted or commissioned by CETU and targets experienced professionals. While every possible precaution has been taken during their development and validation, they may contain errors. Under no circumstances may CETU be deemed liable for any direct or indirect damage that may be caused by using this software. Any users who detect errors or inaccuracies when deploying the software are invited to notify CETU.

Tunnels Study Centre 25, avenue François Mitterrand Case n°1 69674 BRON - FRANCE Tél.: 33 (0)4 72 14 34 00 – Fax: 33 (0)4 72 14 34 30 [email protected] www.cetu.developpement-durable.gouv.fr

1

CONTENTS 1

2

GETTING STARTED WITH CAMATT 2.20__________________________________5 1.1

Presentation of the application

5

1.2

Installing, launching and uninstalling the application 1.2.1 Windows 1.2.2 Linux

5 5 6

1.3

General working scheme

7

USING CAMATT 2.20__________________________________________________8 2.1

Presentation of the main interface

8

2.2

Menus 2.2.1 “File” menu

9 9

New Open Close Close all Save Save as Save all Duplicate Print preview Print Preferences Recent documents Quit

2.2.2

9 9 10 10 10 11 11 11 12 13 13 13 14

“Edit” menu

15

Undo Redo Delete Selection mode Select all Previous Next Zoom in Zoom out Zoom box View all Move Grid Group devices Ungroup devices

2.2.3

15 15 15 15 16 16 16 16 16 17 17 17 17 17 17

“Network” menu

18

Tunnel Ramp Jet fan array Injector Blowing vent Extraction damper Massive extraction Local head loss Aeraulic transparency Traffic interruption Fire

2.2.4

18 22 24 25 26 27 28 29 30 31 32

“Parameters” menu

34

Tunnel / Ramps

34

“Tunnel sections” tab “Ramps” tab “Local head losses” tab

35 36 37

Devices

38

“Distributed ventilation” tab “Jet fans” tab “Injectors” tab

40 40 40

2

“Blowing vents” tab “Extraction dampers” tab “Massive extraction” tab “Aeraulic Transparencies” tab “Traffic Interruptions” tab The button The and buttons

Pressure at portals Fire Pollution Traffic Environment Data summary

2.2.5

44 46 47 48 49 50

“Simulation” menu

51

Fire mode Pollution mode

2.2.6

51 51

“Results” menu

53

Plot results

53

Curves f(x) and f(t) Contour lines f(x,t) Viewing out-of-service jet fans

54 56 57

Show traffic Export results Export traffic results

2.2.7

58 59 61

“Libraries” menu

62

Wall materials Pollutants

2.2.8

62 63

“?” menu

66

Help… About…

66 66

2.3

Toolbar

67

2.4

Drawing sheet 2.4.1 Drawing area 2.4.2 Banner

69 69 70

Ramp angle Slopes of tunnel sections Tunnel orientation Devices

2.4.3 2.4.4

3

41 41 41 42 42 42 43

70 70 70 71

Legend Scale

71 71

SOLVED EQUATIONS________________________________________________ 72 3.1

Conservation of mass

72

3.2

Conservation of the momentum 3.2.1 Linear source terms (or sinks)

72 74

Buoyancy forces Drag (air friction) forces on tunnel walls Vehicle forces on the air

3.2.2

Local source terms (or sinks)

76

Driving forces communicated to the air by a jet fan array Driving forces communicated to the air by an injector Forces due to air drag in turbulence zones

3.3

74 74 74

Conservation of enthalpy 3.3.1 Amount of heat emitted by the seat of the fire 3.3.2 Convective heat transfers with walls 3.3.3 Radiant heat transfers with walls 3.3.4 Transfers of heat during air blowing Distributed blowing vents Local blowing vents Injectors Aeraulic transparencies Air entering via the portals

76 76 76

77 77 78 78 78 79 79 79 79 80

3

3.3.5

Transfers of heat during air extraction Distributed extraction dampers Local extraction dampers Massive extractions Aeraulic transparencies Air exiting via the portals

80 81 81 81 81 82

3.4

Heating of walls

82

3.5

Thermodynamic equations 3.5.1 Equation of state 3.5.2 Specific enthalpy

83 83 83

3.6

Transport of a passive scalar 3.6.1 Gaseous pollutants

84 84

Emissions of gaseous pollutants from the seat of a fire Emissions of gaseous pollutants by road traffic Distributed blowing vents Distributed extraction dampers Local blowing vents Local extraction dampers Injectors Massive extractions Aeraulic transparencies Air entering via the portals Air exiting via the portals

3.6.2

Air opacity

85 85 85 86 86 86 86 86 87 87 87

88

Emissions of soot from the seat of a fire Emissions of particulates from road traffic Distributed blowing vents Distributed extraction dampers Local blowing vents Local extraction dampers Injectors Massive extractions Aeraulic transparencies Air entering via the portals Air exiting via the portals

4

89 89 89 89 90 90 90 90 91 91 91

1

GETTING STARTED WITH CAMATT 2.20

1.1 Presentation of the application Annex 1 of the French inter-ministerial circular No. 2000-63 of 25 August 2000 relating to safety in the French road tunnel network requires a safety dossier for all tunnels exceeding 300 m in length. In particular, this dossier includes a specific hazard investigation, describing the accidents, of any origin whatsoever, that are likely to occur during operational phases, together with their type and the magnitude of their possible impact. In 2003, in order to assess the impacts of an in-tunnel fire and, more specifically, to describe the changes that take place in ambient tunnel conditions, mainly in the first 30 minutes following an outbreak of fire, the CETU developed CAMATT1 to model road tunnel airflow in the presence of fire. In addition to this specific use for hazards studies, CAMATT is also used to size road tunnel ventilation systems. Eight years of use of CAMATT revealed the need to develop a new release, the 2.20, aimed at correcting the various listed bugs, improving the numerical convergence of calculations and integrating a new graphical user interface, together with new functionalities such as: 

an option for modelling fires, traffic or equipment in a ramp



an option for viewing traffic distribution within a tunnel and any related ramps at any given moment in time



a module for making calculations under stationary operating conditions used to model the distribution of pollutants in a tunnel and any related ramps during normal operating conditions



the portability of the solver and the graphics interface to Linux

1.2 Installing, launching and uninstalling the application 1.2.1 Windows Description of the installation As default, CAMATT 2.20 is installed in the C:\Program Files\CAMATT 2.20 folder. After the installation, the CAMATT 2.20 file tree looks like this:

The aide folder contains on-line software support in the form of a PDF file. The bin folder contains the executable version of the software together with the libraries required for its correct operation (bin\lib folder). The jre folder contains the virtual JAVA machine used to self-start the JAVA programme (with no additional installation). For each machine user, a folder named .camatt is created in their folder C:\Documents and Settings\loginUtilisateur the first time the application is launched. This folder contains the following directories:

1

Acronym for CAlcul Mono-dimensionnel Anisotherme Transitoire en Tunnel (one-dimensional anisothermal transient calculation in tunnels)

5



bdd This folder contains the bdd.xml file grouping all the pollutant and material characteristics. This file is updated via the application’s graphical interface.



Export This folder is automatically used to save all the *.csv files that can be exported from the application’s graphics interface (data summary, aeraulics calculation result or traffic distribution for the selected scenario at any given time).



Preferences This folder contains the .xml file preferences that group all the application preferences defined by the user using the “Preferences” command in the “File” menu, i.e.: ▪ export folder for the data and results summary ▪ pollutant definition units (ppm or mg/m3) ▪ drawing sheet and curve parameters ▫ colour and thickness of the lines symbolising tunnels or ramps ▫ show or hide the scale ▫ show or hide the grid ▫ show or hide the key ▫ show or hide out-of-service jet fans on the curves ▪ the list of buttons on the toolbar

Launch To launch CAMATT 2.20, double-click the installation process.

icon generated automatically on the desktop during the

The application can also be accessed via the Start/Programs/CAMATT 2.20 menu or by double-clicking on a *.cmf scenario file generated by the application. Illustration:

When using CAMATT 2.20 for the first time, it is recommended to select the work folder to which will be exported the files that can be generated by CAMATT 2.20. To do this, use the “Preferences” command in the “File” menu.

Uninstall To uninstall CAMATT 2.20, click Uninstall CAMATT 2.20 in the Start/Programs/CAMATT 2.20 menu. You also need to delete the .camatt folder located in the directory C:\Documents and Settings\loginUtilisateur for each user.

1.2.2 Linux Description of the installation When the camatt-2.20-EN-linux.tar.gz package (or camatt-2.20-FR-linux.tar.gz for the French version) is uncompressed in a folder of the user choice, the CAMATT-2.20 directory is created. The file tree in this folder is as follow: The aide folder contains on-line software support in the form of a PDF file. The bin folder contains the executable version of the software together with the libraries required for its correct operation (bin\lib folder). The jre folder contains the virtual JAVA machine used to self-start the JAVA programme (with no additional installation). For each machine user, a .camatt folder is created in their $HOME folder the first time the application is launched. This folder contains the following directories:

6



bdd This folder contains the bdd.xml file that groups all the pollutant and material characteristics. This file is updated via the application’s graphics interface.



Export This folder is automatically used to save all the csv files that can be exported from the application’s graphics interface (data summary, aeraulics calculation result or traffic distribution for the selected scenario at any given time).



Preferences This folder contains the .xml file preferences that group all the application preferences defined by the user using the “Preferences” command in the “File” menu, i.e.: ▪ export folder for the data and results summary ▪ pollutant definition units (ppm or mg/m3) ▪ drawing sheet and curve parameters ▫ colour and thickness of the lines symbolising the tunnel or ramps ▫ show or hide the scale ▫ show or hide the grid ▫ show or hide the key ▫ show or hide out-of-service jet fans on the curves ▪ the list of buttons on the toolbar

Launch To launch CAMATT 2.20, double-click the camatt-2.20.sh script located at the root level in the CAMATT 2.20 directory in the install folder. The application can also be launched by typing the following command line in the install directory: ./camatt-

2.20.sh Uninstall To uninstall CAMATT 2.20, you need to delete the folder CAMATT 2.20 and also the .camatt folder located in your $HOME directory.

1.3 General working scheme CAMATT 2.20 simulations are performed based on scenarios saved in XML files with a *.cmf extension. A scenario corresponds to a tunnel with its ramps, if any, and its equipment modelled in a drawing sheet and linked to a set of time, environment and traffic parameters that make it possible to run the simulation. Before being able to run a simulation though, it is vital to enter all the scenario elements such as the characteristics of the tunnel and any related ramps, the equipment and their related controls, the traffic, the fire and its evolution, etc. Until these elements have been entered, the commands in the “Results” menu used to launch the simulations remain shaded. Once a simulation has been run, the results are recorded when saving the scenario to a binary file with a *.res extension given the same name as the scenario. Simulation results can be accessed via the commands in the “Results” menu that remains shaded until the simulation has been completed. They can be viewed using the curves describing airflow (velocity, flow rate, total pressure or static pressure), changes in ambient conditions (air temperature and pollutant concentrations) and wall temperatures in the tunnel or any related ramps. They can also be exported to a *.csv file that will be saved in the selected folder using the “Preferences” command in the “File” menu. WARNING *.cmf files generated under CAMATT 1.13 to describe a scenario are not compatible with CAMATT 2.20.

7

2

USING CAMATT 2.20

2.1 Presentation of the main interface The main interface of the CAMATT 2.20 release comprises: 

a menu bar



a toolbar



a drawing sheet

Illustration: Menus Toolbar

Drawing sheet

These three elements are described in sections 2.2, 2.3 and 2.4 of this User Guide.

8

2.2 Menus 2.2.1 “File” menu The “File” menu in the menu bar is mainly used to handle scenarios (create, open, close, save, print and duplicate) and to access application preferences. Illustration:

New This command is used to open a new blank drawing sheet. This new drawing sheet is named “Scenarioi” where i is the number of new drawing sheets created by the user. Note that the blank drawing sheet “Scenario1” is generated automatically on opening CAMATT. This command can also be accessed via the keyboard shortcut Ctrl+N. The user can create as many new drawing sheets as they wish and switch between them by simply clicking on the corresponding tab. Illustration:

Open This command is used to open an existing scenario using a dialog in which the user selects the *.cmf file to be opened, then clicks . This command can also be accessed via the keyboard shortcut Ctrl+O. The user can also select several files to be opened using the Ctrl or Shift keys. Each scenario is then loaded in a tab.

9

Illustration:

Illustration:

Close This command is used to close the selected scenario. If the user has made changes, a message is displayed asking them whether they want to save the changes made to the current scenario. Any scenarios that have been changed but not saved are identified by a star (*) next to the scenario’s name. The user can also close a scenario by clicking the cross on the left side of the tab. Illustration:

Illustration:

Close all This command is used to close all the open scenarios. If the user has made changes to one or more scenarios, a message is displayed for each modified scenario, asking them whether they want to save the changes.

Save This command is used to save the selected scenario as a *.cmf file. This command can also be accessed via the keyboard shortcut Ctrl+S. 10

If the scenario has already been saved, the previous file version is overwritten. If the user is saving the scenario for the first time, they are invited to select the file name and the folder via a dialog. There are no restrictions on the file name or location of a folder (hard disk or network). Illustration:

Save as This command is used to save the selected scenario as a *.cmf file using a dialog in which the user can select the file name and folder. There are no restrictions on the file name or location of the folder (hard disk or network).

Save all This command is used to save each open scenario as a *.cmf file. Scenarios are automatically given the file name “Name of the scenario.cmf”. Also, if the folder already contains a file of the type “Name of the scenario .cmf", the previous file version is overwritten. If the user is saving one or more scenarios for the first time, they are invited to select a file name and folder for each scenario via a dialog. There are no restrictions on the file name or location of the folder (hard disk or network).

Duplicate This command is used to duplicate the selected scenario in full. CAMATT then automatically generates a new scenario by copying the modelled tunnel into a new drawing sheet (new tab) that contains all the parameters for the selected scenario. While this duplicate has exactly the same parameters as the originating scenario, these two scenarios are completely separate. Changing a parameter on one of the scenarios has no effect on the parameters of the other scenario. This new scenario is automatically named “Scenarioi” where i is the number of new scenarios created by the user; i is always strictly greater than 1 as the “Scenario1” scenario is generated automatically on opening CAMATT.

11

Illustration:

Print preview This command launches a graphics interface used to show the diagram as it will be printed when the user starts the print. This interface is also used to change the layout of the document to be printed and to start the print using the and buttons respectively. Illustration:

12

Print This command is used to print the part of the selected drawing sheet that can be seen on the display using a dialog in which the user can enter the printing parameters: 

choice of printer



properties of the selected printer



number of copies

Illustration:

Preferences This command is used to open the application preferences dialog that lets the user change the following items: 

export directories for the results and data summary



pollutant definition unit (ppm or mg/m3)



drawing sheet and curve parameters colour and thickness of the lines symbolising the tunnel or ramps show or hide the scale show or hide the grid show or hide the key show or hide out-of-service jet fans on the curves

▪ ▪ ▪ ▪ ▪ 

show buttons on the toolbar

Illustration:

Recent documents This command is used for quick access to the last five documents opened by the user and opens a scenario directly (selected from the list of most recently opened documents) without using the “Open” command in the “File” menu. 13

Illustration:

Quit This command is used to close and quit the application. If the user changes one or more scenarios before closing and quitting the application, a dialog is displayed asking them whether they wish to save the changes made to the scenarios.

14

2.2.2 “Edit” menu The “Edit” menu in the menu bar is used to access the various commands specific to the drawing sheet. This menu is also used to group and ungroup equipment of the same type. Illustration:

Undo This command is used to cancel the last action performed on the drawing sheet. For example, it lets the user cancel the insertion of an element, or delete or move an element. This command does not, however, have any effect on the zoom. This command can also be accessed via the keyboard shortcut Ctrl+Z.

Redo This command is used to repeat the last action cancelled on the drawing sheet, except where this involved an action on the zoom. This command can also be accessed via the keyboard shortcut Ctrl+Y.

Delete This command is used to delete one or more elements previously selected by the user. This command can also be accessed via the keyboard shortcut Del.

Selection mode Switching to the application’s select mode selects one or more elements in the drawing sheet in order to delete or move them. If several equipment of the same type are selected, they can be grouped in order to define a single control for them all. When the application is in select mode, the toolbar button is shown on a white background and a tick appears in front of the corresponding menu. Illustration:

15

The chosen element is selected by clicking on it; the element can be moved by left-clicking the selected element and then dragging it. When a tunnel section (or ramp) is selected, it is highlighted by the display of a green square at each edge. When one of these edges also corresponds to one of the ends of the tunnel, a red rather than a green square is displayed. Illustration:

When a piece of equipment is selected, it is highlighted by the display of four yellow squares outlining it. Illustration:

When a group of equipment is selected, it is highlighted by the display of four green squares outlining each piece of selected equipment. Selecting one element in a group results in the automatic selection of all the other elements in this group. Illustration:

Several elements can be selected simultaneously by pressing the Ctrl key when selecting each equipment using the mouse, or by selecting an area in the window by left-clicking the mouse while dragging it.

Select all This command is used to simultaneously select all the elements in the diagram. This command can also be accessed via the keyboard shortcut Ctrl+A. Illustration:

Previous This command is used to cancel the last action performed on the zoom and to go back to the image’s previous display.

Next This command can only be accessed if the “Previous” command has been used, otherwise it remains shaded. It is therefore used to cancel the last action performed on the zoom with the “Previous” command and to go back to the image’s previous display.

Zoom in This command is used to zoom in on the drawing sheet.

Zoom out This command is used to zoom out on the drawing sheet.

16

Zoom box This command is used to zoom in or out of an area on the selected drawing sheet that the user has selected within a rectangle using the mouse.

View all This command is used to automatically adjust the zoom to give an overall view of the modelled tunnel.

Move Switching to the application’s pan mode lets the user move the whole diagram around the drawing sheet using the mouse, i.e. in order to centre it. When the application is in pan mode, the toolbar button is shown on a white background, a tick appears in front of the corresponding menu and the mouse pointer is shown as a hand. Illustration:

Grid This command is used to display or delete the drawing sheet grid. This grid helps to place elements on the drawing sheet. The grid is automatically displayed on the drawing sheet area. However, the user can mask it if they wish using the “Preferences” command in the “File” menu. When the grid is displayed, the toolbar button is shown on a white background and a tick appears in front of the corresponding menu. Illustration:

Group devices This command is used to group several devices of the same type that were previously selected by the user so as to enter their control characteristics in one single, simultaneous action; a single device can only belong to one group. The devices to be grouped are selected by pressing the Ctrl key when selecting each piece of equipment with the mouse, or by using the mouse to select an area in the window by left-clicking the mouse and dragging it. If the user selects a device already belonging to a group, all devices in that group will be selected, each one being outlined by four green squares. Ungroup devices This command is used to ungroup devices of the same type that were previously grouped earlier by the user.

17

2.2.3 “Network” menu The “Network” menu in the menu bar is used to model the tunnel with, where applicable, its ramps, ventilation equipment and closure systems. Illustration:

On opening a new drawing sheet, all the commands are shaded except for those used to model a tunnel. Modelling a tunnel on the drawing sheet activates all other commands and deactivates that used to model a tunnel as only one tunnel can be modelled on the drawing sheet at any given time.

Tunnel This command is used to insert a tunnel comprising one or more sections in the drawing sheet. Each tunnel section is delineated by two nodes: 

one “upstream” node corresponding to the first node created on the drawing sheet



one “downstream” node corresponding to the second node created on the drawing sheet

Note that, even after having inserted a tunnel on the drawing sheet, you can still change the length of the tunnel or add a tunnel section by acting directly on the drawing sheet rather than using the “Tunnel” command, which has been deactivated. ► To insert a tunnel on the drawing sheet

1) Select the “Tunnel” command. Illustration:

18

2) First, left-click on the drawing sheet with the mouse. A left-click of the mouse creates the upstream node for the first tunnel section. Illustration:

left click

3) Move the mouse without clicking. The length of the inserted tunnel section is displayed for information. Illustration:

4) Click on the drawing sheet a second time using a right or left-click of the mouse. A left-click creates the downstream node for the section maintaining the “draw tunnel section” mode active. The user can therefore create as many sections as they wish by repeating operation 3 with a left-click of the mouse. The right-click is used to create the downstream node of the section by deactivating the “draw tunnel section” mode. This action is used to create the downstream node for the last tunnel 19

section. Illustration of a right-click (tunnel with a single section):

right click

Illustration with a left-click, followed by a right-click (tunnel with two sections):

left click

right click

Right-clicking on the mouse also automatically generates a local head loss and imposed pressure condition at each end of the tunnel. ► To change the length of a tunnel section via the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then left-click the mouse to select the tunnel section that needs to have its length changed. 2) Point the mouse on the upstream or downstream node of the end of the selected tunnel section and then left-click the mouse.

20

Illustration:

left click

3) Left-click and drag the mouse. The new length of the tunnel section is displayed for information. Illustration:

with left click

4) Release the mouse’s left button to place the node in its new position. ► To add a tunnel section via the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then left-click the mouse to select the tunnel end section to which the new tunnel section is to be added. 2) Point the mouse on the tunnel end’s upstream or downstream node depending on which end section has been selected, then press the Ctrl key and left-click the mouse.

21

Illustration with the most downstream end section selected:

left clik + Ctrl

3) Left-click and drag the mouse while holding down the Ctrl key. The length of the newly inserted tunnel section is displayed for information. Illustration:

with left click + Ctrl

4) Release the mouse’s left button to position the upstream or downstream node of the newly inserted tunnel section depending on which end section has been selected. Releasing the left button deactivates the “tunnel line” mode and automatically relocates the head loss and the imposed pressure condition to the new tunnel portal.

Ramp This command is used to insert a ramp with a single section. Ramps can only be inserted at the junction between two tunnel sections. It is therefore impossible to place a ramp at the end of tunnel. 22

It is also impossible to place two concurrent ramps at the same junction between two tunnel sections. ► To insert a ramp on the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then select one of the two sections between which the ramp is to be inserted. 2) Select the “Ramp”command. Illustration:

3) Point the mouse on the node corresponding to the junction between the tunnel and the ramp and left-click on the mouse. Illustration:

left click

4) Drag the mouse while holding the left button in a direction other than that of the tunnel. The length of the inserted ramp is displayed for information.

23

Illustration:

5) Release the mouse’s left button to position the ramp’s upstream node 2. Releasing the left button deactivates the “ramp line” mode and automatically generates a head loss and an imposed pressure condition at the end of the ramp.

Jet fan array This command is used to insert a jet fan array in tunnel or a ramp. A jet fan is a fan attached to a tunnel wall or ceiling that is used to add a local momentum source term in the longitudinal direction without adding a mass source term. A jet fan array consists in a group of several jet fans installed at the same location. ► To insert a jet fan array into a drawing sheet

1) Select the “Jet fan array” command. Illustration:

When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

2

CAMATT 2.20 automatically generates an entrance ramp

24

Illustration:

2) Point the mouse at the place where the jet fan array is to be inserted and left-click on the mouse. The array is then added to the drawing sheet and the jet fan characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other jet fan arrays, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the jet fan arrays have been added, select the “jet fan array” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the jet fan arrays have been added, the “Group devices” command in the “Edit” menu can be used to regroup several jet fan arrays so as to define their joint control characteristics.

Injector This command is used to insert an injector in a tunnel or a ramp. An injector is a fan that is located either in a ventilation plant or in a duct, and used to deliver a directional jet of outside air into a tunnel. It can therefore be used to make local additions of both a momentum source term in the longitudinal direction and a mass source term. ► To insert an injector on the drawing sheet

1) Select the “Injector” command. When this command is activated, the button in the toolbar is shown on a white background and a tick appears in front of the corresponding command. Illustration:

25

2) Point the mouse at the place where the injector is to be inserted and left-click on the mouse. The injector is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other injectors, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the injectors have been added, select the “Injectors” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the injectors have been added, the “Group devices” command in the “Edit” menu can be used to regroup several injectors so as to define their joint control characteristics.

Blowing vent This command is used to insert a blowing vent in a tunnel or a ramp. A blowing vent is used to blow external air into a tunnel at ambient temperature, perpendicular to the airflow in the tunnel. It can therefore be used to make local additions of a mass source term without adding a momentum source term. ► To insert a blowing vent in the drawing sheet

1) Select the “Blowing vent” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command. Illustration:

2) Point the mouse at the place where the blowing vent is to be inserted and left-click on the mouse. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

26

Illustration:

left click

To add other blowing vents, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the blowing vents have been added, select the “Blowing vents” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the blowing vents have been added, the “Group devices” command in the “Edit” menu can be used to regroup several blowing vents so as to define their joint control characteristics.

Extraction damper This command is used to insert an extraction damper in a tunnel or a ramp. An extraction damper is used to extract air from the tunnel locally as required perpendicular to the airflow in the tunnel. It therefore makes it possible to extract mass source terms locally without adding a momentum source term. NOTE In contrast to massive extraction, the mass flow rate extracted by an extraction damper does not depend on the temperature of the extracted air. It is therefore constant and equal to ρoQv, where ρo is the density of ambient air and Qv is the flow rate of the extraction device located upstream of the extraction damper. This assumes, therefore, that the extraction fans are located in an area sufficiently far away from the fire not to be affected by the temperature. ► To insert an extraction damper into the drawing sheet

1) Select the “Extraction damper” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding menu. Illustration:

27

2) Point the mouse at the place where the extraction damper is to be inserted and left-click on the mouse. The extraction damper is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other extraction dampers, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the extraction dampers have been added, select the “Extraction damper” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the extraction dampers have been added, the “Group devices” command in the “Edit” menu can be used to regroup several extraction dampers so as to define their joint control characteristics.

Massive extraction This command is used to insert a massive extraction in a tunnel or a ramp. As with an extraction damper, a massive extraction is used to extract air from the tunnel locally, perpendicular to the airflow in the tunnel. It therefore makes it possible to extract mass source terms locally without adding a momentum source term. NOTE In contrast to an extraction damper, the mass flow rate extracted by a massive extraction depends on the temperature of the extracted air. This equals ρQv, where ρ is the density of air in the tunnel opposite the massive extraction and Q v is the massive extraction flow rate. This therefore assumes that the extraction fans are located in the immediate vicinity of the extraction point. ► To insert a massive extraction into the drawing sheet

1) Select the “Massive extraction” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

28

Illustration:

2) Point the mouse on the tunnel at the place where the massive extraction is to be inserted and leftclick on the mouse. The massive extraction is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other massive extractions, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the massive extractions have been added, select the “Massive extraction” command to deactivate it. The toolbar button no longer appears on white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the massive extractions have been added, the “Group devices” command in the “Edit” menu can be used to regroup several massive extractions so as to define their joint control characteristics.

Local head loss This command is used to insert a local head loss in a tunnel or ramp, generally caused by a sudden change in the cross-section area. ► To insert a head loss in the drawing sheet

1) Select the “Local head loss” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command. Illustration:

29

2) Point the mouse at the place where the local head loss is to be inserted and left-click on the mouse. The local head loss is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other local head losses, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the local head losses have been added, select the “Local head loss” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Aeraulic transparency This command is used to insert an aeraulic transparency in a tunnel or ramp. An aeraulic transparency is a large ceiling opening that connects with the outside. Depending on the sign of the pressure difference on either side of the aeraulic transparency, air is either extracted from or blown into the tunnel. This exchange is always perpendicular to the airflow in the tunnel. Therefore, depending on the sign of the pressure difference on either side, an aeraulic transparency is used to locally subtract or add a mass source term without adding a momentum source term. NOTE An aeraulic transparency is modelled as a local head loss with a coefficient of 1.5 corresponding to a narrowing and then a sudden widening, scaled to the cross-section of the aeraulic transparency, followed by pressurizing to ambient pressure. When air is extracted from the tunnel, its temperature is that of the air in the tunnel opposite the aeraulic transparency; when air is blown into the tunnel, its temperature is that of ambient air. ► To insert an aeraulic transparency in the drawing sheet

1) Select the “Aeraulic transparency” command. When this command is activated, the button of the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

30

Illustration:

2) Point the mouse at the place where the aeraulic transparency is to be inserted and left-click on the mouse. The aeraulic transparency is then added in the drawing sheet and its characteristics can be entered via the menu “Parameters". Illustration:

Left click

To add other aeraulic transparencies, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the aeraulic transparencies have been added, select the “Aeraulic transparency” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the aeraulic transparencies have been added, the “Group devices” command in the “Edit” menu can be used to regroup several aeraulic transparencies so as to define their joint control characteristics.

Traffic interruption This command is used to insert a traffic interruption in a tunnel or ramp. A traffic interruption is a barrier, traffic light or any other system used to stop vehicles located upstream (in relation to the direction of traffic). ► To insert a traffic interruption in the drawing sheet

1) Select the “traffic interruption” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command. Illustration:

31

2) Point the mouse at the place where the traffic interruption is to be inserted and left-click on the mouse. The traffic interruption is then added to the drawing sheet and its control characteristics can be entered via the “Parameters” menu. Illustration:

left click

To add other traffic interruptions, just repeat this operation as many times as necessary using the mouse’s left button. 3) Once all the traffic interruptions have been added, select the “traffic interruption” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command. This command is also deactivated automatically if another command is activated. Once all the traffic interruptions have been added, the “Group devices” command in the “Edit” menu can be used to regroup several aeraulic transparencies so as to define their joint control characteristics.

Fire This command is used to insert a fire in a tunnel or ramp. Only one single fire can be modelled. ► To insert a fire in the drawing sheet

1) Select the “Fire” command. When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command. Illustration:

2) Point the mouse at the place where fire is to be inserted and left-click on the mouse. The fire is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

32

Illustration:

left click

3) Once the fire has been added, the command is automatically deactivated as only one single fire can be modelled at a time. The toolbar button is shaded and the symbol is no longer visible in front of the corresponding command.

33

2.2.4 “Parameters” menu The “Parameters” menu in the menu bar is used to enter all the data for the model, thereby parametering:  tunnel sections and any ramps  equipment and their controls  pressure conditions at interfaces with the outside  fire  pollutant concentrations in ambient air  traffic  tunnel environment

This menu is also used to export a *.txt file summarizing the data for the model entered by the user. Illustration:

On opening a new drawing sheet, all the commands are shaded except for that used to define the tunnel environment. Modelling a tunnel and any related ramps and equipment using the “Network” menu activates all the commands, with the exception of the “Fire” and “Data summary” commands. The “Fire” command is only activated if a fire has been modelled in the drawing sheet using the “Fire” command in the “Network” menu. The “Data summary” command is only activated when all the elements modelled in the drawing sheet using the “Network” menus (tunnel, ramps, equipment and fire) have been fully parametered using the “Tunnel / Ramps", “Devices” commands and, where applicable, the “Fire” command in the “Parameters” menu. Illustration of a tunnel modelled with no fire on the drawing sheet:

Tunnel / Ramps This command uses a dialog to enter the characteristics for the tunnel sections, ramps and local head losses that are automatically generated at the ends of a tunnel and at any related ramps for the selected scenario. The dialog contains two or three tabs depending on whether there is a ramp.

34

The first tab, entitled “Tunnel sections", is used to enter the characteristics of each tunnel section modelled in the drawing sheet. The second tab, entitled “Ramps", is only displayed if a ramp has already been modelled in the drawing sheet. It is used to enter the characteristics of each ramp modelled in the drawing sheet. The last tab, entitled “Local head losses", is used to enter local head loss coefficients at the ends of the tunnel and any ramps, where applicable. Illustration of the “Tunnel sections” tab:

Illustration of the “Ramps” tab:

Illustration of the “Local head losses” tab:

The user moves around the tables either by pointing and then left-clicking the mouse on the fields to be selected, or by using the following keyboard keys: 

select the cell content in the next column: Tab



select the cell content in the previous column: Maj + Tab



select the cell content in the next line: ↓



select the cell content in the previous line: ↑

NOTE To be taken into account, the value entered in a field must be confirmed either by clicking outside the selected field, or by pressing the Enter key. The following tables describe the fields to be filled in for each of the 3 tabs, their default value and their area of validity: ► “Tunnel sections” tab Field

Description

Unit

Default value

Area of validity

Label

Alphanumeric code used to name the tunnel section

-

Tunnel sect. No i (I)

Character string

Length

Length of the tunnel section

m

Length indicated when creating the section in the drawing sheet (II)

Positive real number

Cross-section area

Cross-section through the tunnel section

m2

0 (III)

Real number belonging to ]0;1000[

Perimeter

Perimeter of the tunnel section or ramp

m

0 (III)

Positive real number

35

Field

Description

Unit

Default value

Area of validity

%

0

Real number

Value of the tunnel section slope in the upstream - downstream direction. Slope (- if downhill) Negative if the tunnel section is descending and positive if it is rising Friction coefficient

Friction coefficient of the tunnel section walls

-

0.025

Real number belonging to ]0;1]

Material 1

First type of material used for the tunnel section walls. This is chosen from the list of wall materials defined in the “libraries” menu

-

Concrete

-

Material 2

Second type of material used for the tunnel section walls. This is chosen from the list of wall materials defined in the “libraries” menu

-

Concrete

-

Proportion of material 1

Proportion of material 1 in relation to material 2 in a part of the tunnel section

%

100

Real number belonging to ]0;100]

(I)

i corresponds to the tunnel section creation ranking. If a ramp is inserted between tunnel sections i and i+1, tunnel sections ranked higher than i+1 are automatically incremented by 1.

(II)

The length of the tunnel section is automatically updated by the application according to the position of the end nodes on the drawing sheet. Conversely, if the user modifies the length of the tunnel section in this field, the tunnel section modelled in the drawing sheet will be automatically updated.

(III)

The default value does not belong in the area of validity; it must therefore be replaced by a valid value.

► “Ramps” tab Field

Description

Unit

Default value

Area of validity

Label

Alphanumeric code used to name the ramp

-

Ramp No. j (I)

Character string

Length

Length of the ramp

m

Length indicated when creating the ramp in the drawing sheet (II)

Positive real number

Cross-section area

Cross-section of the ramp

m2

0 (III)

Real number belonging to ]0;1000[

Perimeter

Perimeter of the ramp section

m

0 (III)

Positive real number

Slope (- if downhill)

Value of the ramp slope in the upstream - downstream direction. Negative if the ramp is descending and positive if it is rising

%

0

Real number

Friction coefficient

Friction coefficient of the ramp walls

-

0,025

Real number belonging to ]0;1]

Angle

Angle of the ramp with the tunnel (IV)

°

Angle indicated when creating the ramp in the drawing sheet (V)

Real number belonging to ]0;90[

Orientation

Entrance or exit ramp

-

Entrance

Entrance and Exit

Traffic direction

Direction of traffic flow in the tunnel associated with the ramp

-

Upstr. - Downst.

"Upstr. - Downst. “ and "Downst. Upstr. “

Material 1

First type of material used for the ramp wall. This is chosen from the list of wall materials defined in the “libraries” menu

-

Concrete

-

Material 2

Second type of material used for the ramp wall. This is chosen from the list of wall materials defined in the “libraries” menu

-

Concrete

-

Proportion of material 1

Proportion of material 1 in relation to material 2 in a section of the ramp

%

100

Real number belonging to ]0;100]

(I)

If a ramp is inserted between tunnel sections i and i+1, j is equal to i+1; tunnel sections ranked higher than i+1 are automatically incremented by 1.

(II)

The length of the ramp is automatically updated by the application according to the position of the end nodes in the drawing sheet. Conversely, if

36

the user modifies the length of the ramp in this field, the ramp modelled in the drawing sheet will be automatically updated. (III)

The default value does not belong in the area of validity; it must therefore be replaced by a valid value.

(IV)

The angle has to be entered by taking account of the direction of traffic in the tunnel associated with the ramp and of the type of ramp entered via the “Direction” and “Orientation” fields respectively. If the direction of traffic in the tunnel associated with the ramp is “Upstream - Downstream", the angle to be entered is:  for an entrance ramp, the angle between the tunnel section located upstream of the junction in the direction of traffic and the ramp  for an exit ramp, the angle between the tunnel section located downstream of the junction in the direction of traffic and the ramp If the direction of traffic in the tunnel associated with the ramp is “Downstream - Upstream", the angle to be entered is:  for an entrance ramp, the angle between the tunnel section located downstream of the junction in the direction of traffic and the ramp  for an exit ramp, the angle between the tunnel section located upstream of the junction in the direction of traffic and the ramp The following table gives all the possible options:

(V)

"Traffic direction” field

"Orientation” field

Upstr. - Downst.

Entrance

Upstr. - Downst.

Exit

Downst. Upstr.

Entrance

Downst. Upstr.

Exit

Angle

The default value does not necessarily belong to the area of validity; it must therefore be replaced by a valid value. Once the dialog has been confirmed, the angle of the ramp is automatically updated in the drawing sheet according to the elements entered in the “Angle", “Orientation” and “Traffic direction” fields.

NOTE In the CAMATT 2.20 release, the function used to take account of head losses at the junction has not been activated as it may cause digital divergence problems with certain flow regimes. Also, the value entered in the “Angle” field has no effect on the calculations. Conversely, this value has to belong to the area of validity ]0;90[. ► “Local head losses” tab Field

Description

Default value

Area of validity

Label

Alphanumeric code used to name the local head loss

Portal loss No. i or Local loss No. j (I)

Character string

Local crosssection area

Cross-section through the tunnel section or ramp at the level of the local head loss

m2

Cross-section through the tunnel section or ramp at the level of the local head loss (II)

Non-modifiable

Reference crosssection area

Cross-section used to calculate the head loss (III)

m2

Cross-section through the tunnel section or ramp at the level of the local head loss

Real number belonging to ]0;1000[

Upst. - Downst. Head loss coeff.

Coefficient representing the head loss for an airflow in the upstream downstream direction

-

0 or 0.5 or 1 (IV)

Positive real number

Downst. - Upst. Head loss coeff.

Coefficient representing the head loss for an airflow in the Downstream - Upstream direction

-

0 or 0.5 or 1 (IV)

Positive real number

Dist. from upstream

(I)

Position of the local head loss

Unit -

Calculated based on the position of the jet fan array Non modifiable or in the drawing sheet (VI) or Real number belonging positioned 0.10 m from a to ]0;l tunnel[ or ]0;l ramp[ portal

(V)

Portal loss No.i describes the head loss located at the level of the tunnel portal. Portal loss No.1 describes the head loss located at the level of the tunnel portal corresponding to the tunnel’s upstream node. Portal loss No.2 describes the head loss located at the level of the tunnel portal corresponding to the tunnel’s downstream node. Portal loss No.i with i>2 describes the head loss located at the level of the ramp portal that always corresponds to a downstream node as the upstream node is the one located at the level of the junction with the tunnel. For each ramp, i takes the value n+2 where n corresponds to the creation ranking of the ramp in the drawing sheet. Local loss No.k describes a local head loss. If a local head loss is inserted in a tunnel or ramp, k is equal to i max + 1. It is then incremented by 1 with each new insertion of a local head loss.

(II)

The interior zone is displayed for information on an orange background and corresponds to the value entered in the “Cross-section area” fields of the “Tunnel sections” and “Ramps” tabs for the “Tunnels / Ramps” command.

(III)

The “reference section” noted Sref appears in the expansion equation for the following head loss: 2 1 Q P=  2 2 Sref

37

avec P   Q (IV)

: head loss : air density : head loss coefficient : flow rate

The head loss coefficient automatically equals 0 except for the head losses located at the portals of a tunnel or ramp. For the head loss located at the level of the tunnel portal corresponding to the tunnel’s upstream node, the head loss coefficient in the upstream downstream direction equals 0.5 and that in the Downstream - Upstream direction equals 1. For the head loss located at the level of the tunnel portal corresponding to the tunnel’s downstream node, the head loss coefficient in the upstream - downstream direction equals 1 and that in the Downstream - Upstream direction equals 0.5. For the head loss located at the level of the ramp portal that always corresponds to a downstream node, the head loss coefficient in the upstream downstream direction equals 1 and that in the Downstream - Upstream direction equals 0.5.

(V)

For a head loss located in the tunnel, the upstream distance corresponds to its position in relation to the tunnel’s upstream node. For a head loss located in a ramp, the upstream distance corresponds to its position in relation to the portal of the ramp for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(VI)

Once the dialog has been confirmed, the position of the local head loss is automatically updated on the drawing sheet.

Devices This command uses a dialog to enter the characteristics of all the equipment modelled in the drawing sheet for the selected scenario, i.e.: 

jet fan arrays



injectors



blowing vents



extraction dampers



massive extractions



aeraulic transparencies



traffic interruptions

It is also used to enter, for each tunnel section and ramp in the drawing sheet, the characteristics of the distributed blown or extracted flow rate. The dialog may therefore contain 1 to 8 tabs depending on the type of equipment modelled in the drawing sheet. The first tab, entitled “Distributed ventilation", is used to enter the characteristics of the distributed blown or extracted flow rate for each tunnel section and ramp. The other tabs, entitled “Jet fans", “Injectors", “Blowing vents", “Extraction dampers", “Massive extractions", “Aeraulic transparencies” and “Traffic interruptions” only appear in this order if the related equipment is modelled in the drawing sheet. They are used to enter the characteristics for each equipment. Illustration of the “Distributed ventilation” tab:

Illustration of the “Jet fans” tab:

Illustration of the “Injectors” tab:

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Illustration of the “Blowing vents” tab:

Illustration of the “Extraction dampers” tab:

Illustration of the “Massive extractions” tab:

Illustration of the “Aeraulic transparencies” tab:

Illustration of the “Traffic interruptions” tab:

All the tabs in the dialog have the same structure; they contain: 

fields used to characterise equipment and its location



for equipment blowing air into a tunnel or ramp, a concentrations in the blown air



a



where applicable, a button that replaces the button used to simultaneously control several equipment of the same type that were previously grouped using the “Group” command in the “Edit” menu

button used to characterise pollutant

button used for individual equipment control

The user moves around the tables either by pointing and then left-clicking the mouse on the fields to be selected, or by using the following keyboard keys: 

select the cell content in the next column: Tab



select the cell content in the previous column: Maj + Tab



select the cell content in the next line: ↓



select the cell content in the previous line: ↑

NOTE To be taken into account, the value entered in a field must be validated either by clicking outside the selected field, or by pressing the Enter key. The following tables describe the fields characterising the equipment to be filled in for each of the 8 tabs, their default value and their area of validity:

39

► “Distributed ventilation” tab Field

Description

Unit

Label

Name of the tunnel section or ramp

-

Distributed blowing flow rate

Value of the distributed blowing flow rate in the tunnel section

Distributed extraction Value of the distributed extraction flow rate flow rate (I)

Default value

Area of validity

Tunnel section No. i or Ramp No. j

Non modifiable (I)

m3.s-1.m-1

0

Positive real number

m3.s-1.m-1

0

Positive real number

The description(s) automatically correspond to those entered in the “Label” fields of the “Tunnel sections” or “Ramps” tab of the “Tunnels / Ramps” command in the “Parameters” menu.

► “Jet fans” tab Field

Description

Label

Name of the jet fan array

Number of jet fans

Unit

Default value

Area of validity

-

Array No. i

Character string

Number of jet fans making up the array

-

1

Positive whole number

Unit free-field thrust

Thrust of a jet fan in the array. All the jet fans in the array are assumed to be identical.

N

0

Real number

Jet velocity

Speed at which air is ejected from a jet fan outlet

m.s-1

30

Positive real number

Efficiency

Overall efficiency of the jet fan array, in particular, factoring in the effects of the wall

-

0,85

Real number belonging to ]0;1]

Max working temperature

Temperature above which the jet fan array is assumed to be destroyed

°C

200

Positive real number

Reference density

Air density corresponding to the conditions under which the array’s jet fan performance was measured

kg.m-3

105

Positive real number

Tunnel cross-sect. area

Cross-section through the tunnel section or ramp at the level of the jet fan array

m2

Cross-section through the tunnel section or ramp at the level of the jet fan array (I)

Non modifiable

Cross-sect. area at jet fans

Cross-section through the tunnel section or ramp opposite the jet fan array

m2

0 (II)

Positive real number

Dist. from upstream

Position of the jet fan array (III)

m

Calculated based on the position of the jet fan array Positive real number on the drawing sheet (IV)

(I)

The interior zone is displayed for information on an orange background and corresponds to the value entered in the fields “Cross-section area” in the “Tunnel sections” and “Ramps” tabs of the “Ramps” command.

(II)

The default value does not belong in the area of validity; it must therefore be replaced by a valid value.

(III)

For a jet fan array located in a tunnel, the upstream distance corresponds to its position in relation to the tunnel’s upstream node.

(IV)

For a jet fan array located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp. Once the dialog has been confirmed, the position of the jet fan array is automatically updated on the drawing sheet.

NOTE To simulate a jet fan array operating in the reverse direction, i.e. in the Downstream - Upstream direction, just enter a negative thrust in the “Unit free-field thrust” field. Simulation of the control of a reversible jet fan array will require the creation of an array with positive thrust jet fans next to an array with an identical set of jet fans, but with negative thrust. These two arrays are controlled by reducing the operating rate of one array while simultaneously increasing the operating rate of the other array. ► “Injectors” tab Field

Description

Label

Name of the injector

Injection flow rate

Blowing flow rate injected into a tunnel or ramp by the injector

Unit m3.s-1

40

Default value

Area of validity

Injector No. i

Character string

0

Positive real number

Field

Description

Jet velocity

Speed at which air is ejected from the injector outlet

Angle with tunnel axis

Unit

Default value

Area of validity

m.s-1

0 (I)

Positive real number

Angle between the tunnel and air jet axes at the injector outlet(II)

°

15

Real number belonging to ]0;180]

Efficiency

Injector efficiency, in particular, factoring in the effects of the wall and the shape of the blowing device

-

05

Real number belonging to ]0;1]

Tunnel cross-sect. area

Cross-section through the tunnel section or ramp at the level of the injector

m2

Cross-section through the tunnel section or ramp at the level of the injector (III)

Non modifiable

Cross-sect. area at injector

Cross-section through the tunnel section or ramp opposite the injector

m2

0 (I)

Positive real number

Dist. from upstream (IV)

Distance between the upstream node of the tunnel end or of the ramp and the injector

m

Calculated based on the position of the injector in the drawing sheet (V)

Positive real number

(I)

The default value does not belong in the area of validity, it must therefore be replaced by a valid value.

(II)

An angle of between 0° and 90° corresponds to a downstream thrust, and an angle of between 90° and 180° corresponds to an upstream thrust.

(III)

The interior zone is displayed for information on an orange background and corresponds to the value entered in the “Cross-section area” field in the “Tunnel sections” and “Ramps” tabs of the “Tunnels / Ramps” command.

(IV)

For an injector located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For an injector located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(V)

Once the dialog has been confirmed, the position of the injector is automatically updated on the drawing sheet .

► “Blowing vents” tab Field

Description

Label

Name of the blowing vent

Blown flow rate

Blown flow rate in a tunnel or ramp via the blowing vent

Distance from upstream (I)

Distance between the upstream node of the tunnel end or of the ramp and the blowing vent

(I)

Unit m3.s-1

m

Default value

Area of validity

Blowing vent No. i

Character string

0

Positive real number

Calculated based on the position of the blowing vent in the drawing sheet

Positive real number

(II)

For a blowing vent located in the tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For a blowing vent located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II)

Once the dialog has been confirmed, the position of the blowing vent is automatically updated in the drawing sheet.

► “Extraction dampers” tab Field

Description

Label

Name of the extraction damper

Extracted flow rate

Flow rate extracted from a tunnel or ramp by the extraction damper

Distance from upstream (I)

Distance between the upstream node tunnel end or of the ramp and the extraction damper

(I)

Unit m3.s-1

m

Default value

Area of validity

Extraction damper No. i

Character string

0

Real number

Calculated based on the position of the extraction damper on the drawing sheet (II)

Positive real number

For an extraction damper located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For an extraction damper located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II)

Once the dialog has been confirmed, the position of the extraction damper is automatically updated on the drawing sheet.

► “Massive extraction” tab Field

Description

Unit

Label

Name of the massive extraction

Extracted flow rate

Flow rate extracted from a tunnel or ramp by massive extraction

Distance from upstream (I)

Distance between the upstream node tunnel end or of the ramp and the massive extraction

m3.s-1

41

m

Default value

Area of validity

Massive extraction No. i

Character string

0

Positive real number

Calculated based on the position of the massive extraction on the drawing sheet (II)

Positive real number

(I)

For a massive extraction located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For a massive extraction located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II)

Once the dialog has been confirmed, the location of the massive extraction is automatically updated on the drawing sheet.

► “Aeraulic Transparencies” tab Field

Description

Label

Name of the aeraulic transparency

Transparency cross-area

Section of the aeraulic transparency

Outside pressure

Relative pressure taken on the external side of the aeraulic transparency in relation to the absolute reference pressure

Distance from upstream (I)

Distance between the upstream node tunnel end or of the ramp and the aeraulic transparency

(I)

Unit

Default value

Area of validity

Aeraulic transp. No.i

Character string

m2

0

Positive real number

Pa

0

Real number

m

Calculated based on the position of the aeraulic transparency on the drawing sheet (II)

Positive real number

-

For an aeraulic transparency located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For an aeraulic transparency located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II)

Once the dialog has been confirmed, the position of the aeraulic transparency is automatically updated on the drawing sheet.

► “Traffic Interruptions” tab Field

Description

Label

Name of the traffic interruption

Distance from upstream (I)

Distance between the upstream node tunnel end or of the ramp and the traffic interruption

(I)

Unit

Default value

Area of validity

-

Traffic interruption No. i

Character string

m

Calculated based on the position of the traffic Positive real number interruption on the drawing sheet (II)

For a traffic interruption located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node. For a traffic interruption located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II)

Once the dialog has been confirmed, the position of the traffic interruption is automatically updated on the drawing sheet.

► The

button

For air blowing equipment in a tunnel or ramp such as distributed or local blowing vents and injectors, or equipment that is likely to blow air, such as aeraulic transparencies, clicking on the button in the “Pollution” column lets the user open a dialog named “Pollution parameters for: label of the device” and enter the blown air pollutant concentrations for the selected equipment. Illustration:

The list of pollutants is that defined in the pollutants library that can be accessed via the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates. The pollutant concentrations for equipment blown air are automatically zero. Pollutant concentrations can be expressed in mg.m-3 or ppm for gaseous pollutants, and in mg.m -3 or m-1 for opacity, according to the units selected in the application preferences using the “Preferences” command in the “File” menu.

42

NOTE Pollutant concentrations for equipment blown air in a tunnel or ramp can be entered in two different ways that should not be confused: 

either by using the

button in the “Devices” dialog



or by using the “Pollution ” command in the “Parameters” menu

The button is used to modify pollutant concentrations for equipment blown air for each separate equipment modelled in the drawing sheet. The “Pollution” command in the “Parameters” menu is used to modify pollutant concentrations for equipment blown air for all the equipment modelled in the drawing sheet. ► The

and

buttons

Clicking on the button in the “Control” column opens a dialog entitled “Device control: description of the selected equipment” and is used to enter the control characteristics for the selected equipment. If several equipment of the same type have been previously grouped using the “Group” command in the “Edit” menu, the button replaces the button. Clicking this button then opens a dialog entitled “Device control: label of the device group” and lets the user enter the joint control characteristics of all the equipment in the selected group. Illustration of the dialog displayed by clicking on the

button:

Illustration of the dialog displayed by clicking on the

button:

While the dialoges are identical for a given piece of equipment, whether this is controlled individually or jointly with other equipment of the same type, they differ significantly depending on the type of equipment and, therefore, on the corresponding tab. 

For the “Distributed ventilation", “Jet fans", “Injectors", “Blowing vents", “Extraction dampers” and “Massive extractions” tabs: The dialog is used to specify the operating conditions for an equipment or a group of equipment according to time in relation to full power operation using a coefficient to be entered in the “Multiplying coeff.” fields. This automatically equals 1. All these equipment are therefore operating at full power right from the start of the simulation.



For the “Aeraulic transparencies” tab The dialog is used to specify the position of the aeraulic transparency, open or closed, according to time. Aeraulic transparencies are automatically closed at the start of the simulation.

43

Illustration:



For the “Traffic interruptions” tab The dialog is used to specify at which time the traffic is to be interrupted by the closure system, i.e. a barrier or traffic light. Illustration:

NOTE No more than one single event may be entered for traffic interruptions. Once the traffic interruption has been activated, it is final. Traffic interruptions have to be activated after the start of the fire; otherwise, they will have no effect. All these dialogs contain: 

a

button for adding an event in equipment control.

Illustration:



a

button for modifying the selected event with the mouse in equipment control



a

button for deleting the selected event with the mouse in equipment control.

Pressure at portals This command is used to enter the pressure conditions and pollutant concentrations imposed at the portals of a tunnel and any related ramps; these represent the model’s limit conditions.

44

Illustration:

Once the dialog has been confirmed, the portal pressure conditions are automatically updated in the drawing sheet. The user moves around the tables either by pointing and then left-clicking the mouse on the fields to be selected, or by using the following keyboard keys: 

select the cell content in the next column: Tab



select the cell content in the previous column: Maj + Tab



select the cell content in the next line: ↓



select the cell content in the previous line: ↑

Clicking on the button in the “Pollution” column opens the dialog entitled “Pollution parameters for: label of the imposed pressure condition” and lets the user enter the pollutant concentrations for the air likely to enter the tunnel via the selected portal. Illustration:

The list of pollutants is that defined in the pollutants library and can be accessed via the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates. Pollutant concentrations for air entering the tunnel via a portal are automatically zero. Pollutant concentrations can be expressed in mg.m-3 or ppm for gaseous pollutants, and in mg.m -3 or m-1 for opacity, depending on the units selected in the application preferences using the “Preferences” command in the “File” menu.

45

NOTE Pollutant concentrations in air that are likely to enter a tunnel or ramp via a portal can be entered in two different ways that should not be confused: 

either using the

button of the “Devices” dialog



or using the “Pollution” command in the “Parameters” menu

The button is used to modify, for each individual portal, the pollutant concentrations for air likely to enter the tunnel via a given portal. The “Pollution” command in the “Parameters” menu is used to modify, for all the portals, the pollutant concentrations for air likely to enter the tunnel via these portals.

Fire This command is used to define the fire to be studied in “Fire mode” via a dialog for the selected scenario. This command is only activated if a fire is modelled in the drawing sheet. The parameters to be entered are: 

start time of the fire



location of the fire in relation to the upstream node of the ramp or tunnel end



type of fire

The fire always starts at t = 00 h 00 min 00 s; its position is calculated automatically based on its location in the drawing sheet. The CAMATT 2.20 release automatically contains the fire load curves for the 12 reference fires defined in leaflet 4 of the guide to road tunnel safety dossiers relating to Specific Hazards Studies, in addition to opacity flows and emission rates for the related pollutants. The mouse can be used to select one of these reference fires by checking the element located in the “Choose” column. Illustration:

The pollutant automatically taken into account for each of these reference fires is carbon monoxide (CO); however, another pollutant may be taken into account by changing the value of the pollutant emission rate. The dialog also contains: 

a button for adding a fire by defining the fire heat release rate curve, its opacity flux and pollutant emission rate via a dialog.

46

Illustration:

This dialog contains: ▪ a field for entering the type of fire. ▪ a button for adding an event to the fire evolution and defining the fire heat release rate curve, its opacity flux and pollutant emission rate at a given moment in time. Illustration:

▪ ▪

The event time needs to be defined in relation to the fire start time; this is a relative rather than an absolute time. The heat release rate figure to be recorded is the fire’s total heat release rate, a third of which is assumed to be dissipated via radiation through the walls directly opposite the fire. Therefore, only two thirds of the recorded heat release rate is used in the calculations. a button for modifying the selected event using the mouse. a button for deleting the selected event using the mouse.



a button for changing the fire selected and highlighted in blue with the mouse via a dialog identical to that described above that lets the user add a fire.



a

button used to delete the fire selected and highlighted in blue with the mouse.

NOTE All the fires listed in the “Fire” dialog make up a library in the same way as those found for wall materials or pollutants in the “Libraries” menu. As with the two others, this library is: 

common to all the scenarios

saved in the bdd.xml file of the .camatt/bdd folder found in the user profile folder in Windows or in the $HOME folder in Linux, and therefore specific to each user. 

All changes or additions to this library will therefore apply to all the scenarios, whether they are new, existing or duplicated, but will only be valid for the user responsible for said change or addition.

Pollution Pollutant concentrations for the air around portals and the air injected into the tunnel or its ramps are always zero. As described earlier in pages 46 and 47 of this User's Guide, clicking on the button lets the user modify this value individually for each portal or each equipment injecting air into the tunnel or its ramps, if any. The “Pollution” command is used to overwrite all these values and to assign to all the equipment modelled 47

in the drawing sheet and to all the portals of the tunnel and its ramps, if any, the same pollutant concentrations for equipment blown air or for air likely to enter the tunnel via one of its portals. Illustration:

The list of pollutants is that defined in the pollutants library that can be accessed using the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates. Pollutant concentrations in ambient air are automatically zero. Pollutant concentrations can be expressed in mg.m-3 or in ppm for gaseous pollutants, and in mg.m -3 or m-1 pour opacity, depending on the units selected in the application preferences via the “Preferences” command in the “File” menu. To assign the same concentration for a given pollutant to all the portals and all the equipment modelled in the drawing sheet, just enter the new value to be taken account of for the selected pollutant and click on the relevant button found in the “Apply to all” column, then quit the dialog by clicking on the button. NOTE The “Pollution” command in the “Parameters” menu only acts on air blowing equipment already modelled in the drawing sheet; it has no effect on any equipment that is modelled in the drawing sheet at a later date. For such equipment, the pollutant concentrations for injected air remain the default value, i.e. zero.

Traffic This command is used to characterise road traffic for the selected scenario. The following table describes the fields to be filled in, their default value and their area of validity: Field

Description

Proportion of HGVs

Proportion of HGVs in the traffic

Sigma_CX for cars

Frontal surface for cars

Sigma_CX for HGVs

Unit

Default value

Area of validity

0

Real number belonging to [0;100]

m2

0,9

Positive real number

Frontal surface for HGVs

m

4,5

Positive real number

Distance between stopped vehicles

Front bumper - front bumper distance for stopped vehicles

m

10

Positive real number

Pollutant emissions

Vehicle pollutant emissions for each tunnel section and ramp, for each pollutant listed in the pollutants library

kg.s-1.m-1

0

Positive real number

Nominal speed

Traffic speed in each traffic direction

km.h-1

70

Positive real number

(I)

-1

0

Positive real number

1

Positive whole number

-

Nominal flux

Vehicle flux in each traffic direction

Number of lanes per direction

Number of lanes in each traffic direction for each tunnel section and ramp (II)

2

veh.h -

(I)

Where there are one or more ramps, the only fluxes to be recorded are those for vehicles entering each end of the marked tunnel in relation to the direction of traffic, the vehicles entering via the entrance ramps, and leaving via the exit ramps. The traffic flux in the other tunnel sections is automatically calculated by the application by conservation of the traffic at tunnel - ramp junctions.

(II)

For two-way traffic, the number of driving lanes is supposed to be the same in each traffic direction.

48

Illustration:

Environment This command is used to characterise the tunnel environment, together with heat transfers with tunnel walls and ramps, if any, for the selected scenario. The following table describes the fields to be filled in in order to characterise the tunnel environment, together with their default value and area of validity: Field

Description

Average altitude

Average tunnel altitude

Ambient air temperature

Mean temperature of ambient air inside the tunnel (I)

(I)

Unit

Default value

Area of validity

m

0

Positive real number

m2

0.9

Real number

This temperature applies to ambient air inside the tunnel or ramp, as well as outside and to a depth of 16 cm in the walls.

Ambient air density is calculated automatically based on the values entered for these two fields according to the following equation: 273.z alt

 o=3,485 .10 −3 .

− Po .10 18400.T To

o

avec o Po To z alt

: density of ambient air : absolute pressure at sea level, i.e. 101 325 Pa : temperature of ambient air inside the tunnel : average tunnel altitude

The following table describes the fields to be filled in in order to characterise heat transfers with tunnel walls and any ramps, together with their default value and area of validity: Field

Description

Min value of radiant heat transfer cœff.

Coefficient for the minimum radiant heat transfer between smoke and tunnel walls and any ramps

Max value of radiant heat transfer cœff.

Coefficient for the maximum radiant heat transfer between smoke and tunnel walls and any ramps

Unit

49

Default value

Area of validity

W.m-2.K-1

0

Positive real number

W.m-2.K-1

100

Positive real number

Field

Description

Wall emissivity

Wall emissivity used to calculate the radiant heat transfer coefficient

View factor

View factor for the tunnel and ramps characterising their shape and used to calculate the radiant heat transfer coefficient

Unit

Default value

Area of validity

-

0.9

Positive real number

-

1

Real number belonging to the interval ]0;1]

Data summary This command is used to export all the data for the selected scenario into a *.csv file. This file takes the name “nomScenario_Recap.csv” and is saved in the “Export” folder specified in the application preferences via the “Preferences” command in the “File” menu. A message is displayed to notify the user that the export has been completed. Illustration:

The file generated can be opened using a text editor such as Excel or Open Office.

50

2.2.5 “Simulation” menu The “Simulation” menu in the menu bar is used to launch the calculation for the selected scenario in either smoke extraction mode or normal extraction mode. Illustration:

On opening a new drawing sheet, all the commands are shaded. They remain shaded and inaccessible until the user has correctly entered all the model data required for the calculations.

Fire mode This command is used to launch the calculation for the selected scenario in “Fire mode” using a dialog to specify: 

the simulation’s ending time



the simulation’s time step

The simulation’s starting time set at 00 h 00 min 00 s cannot be changed, which means that the simulation ending time also corresponds to the duration of the simulation. This is automatically set at 30 minutes. The simulation’s time step is used to define the calculation’s results sampling. This corresponds to the time step between 2 results curves f(t) at successive fixed x. They must not be confused with the calculation’s time step, which is set at 1 s in the code, and that may not be changed by the user. Illustration:

Clicking on the

button executes the calculation in “Fire mode".

NOTE Before executing calculations in “Fire mode", the application automatically checks for the presence of any co-located model elements. If they are found, the calculation is not executed and the user is alerted to the presence of co-located elements. The user then has to move the relevant model element(s) to ensure there are no longer any co-located elements.

Pollution mode This command is used to launch the calculation in “Pollution mode” for the selected scenario. The calculation is made under steady state regime. A message is displayed to notify the user that the calculation has been completed.

51

Illustration:

NOTE As described for the “Fire mode” command, the application automatically checks for the presence of any co-located model elements before executing the calculation.

52

2.2.6 “Results” menu The “Results” menu in the menu bar is used to view the results of the calculation executed in either “Fire mode” or “Pollution mode", and of the export in a *.csv file. If the latest calculation was executed in “Fire mode", then this menu is also used to view traffic distribution according to time in the tunnel and its ramps, if any, and to export the data for a given time to a *.csv file. Illustration:

On opening a new drawing sheet, all the commands are shaded. They remain shaded and inaccessible until the user has executed a calculation in either “Pollution mode” or “Fire mode". Executing a calculation activates some or all of the commands in this menu depending on whether the calculation was executed in “Fire mode” or “Pollution mode”: Illustration of a calculation in “Fire mode” with a modelled fire:

Illustration of a calculation in “Fire mode” with no modelled fire or in “Pollution mode”:

Plot results This command is used to view plot results for the latest calculation executed in either “Fire mode” or “Pollution mode", via a dialog. The mouse is used to click in the dialog to select: 

the part of the tunnel for which the user wishes to view the results: tunnel or ramp



the physical quantities to be displayed from among all the available physical quantities In “Fire mode", the available quantities are: ▪ air temperature ▪ wall temperature ▪ air opacity ▪ pollutant concentration ▪ air velocity ▪ longitudinal flow rate ▪ total pressure ▪ static pressure In “Pollution mode", the available quantities are: ▪ pollutant concentration for all the pollutants listed in the pollutants library, accessible and modifiable using the “Pollutants” command in the “Libraries” menu ▪ air velocity ▪ longitudinal flow rate

53

the type of view for the physical quantities selected for display



In “Fire mode", a physical quantity can be viewed as: ▪ either a spatial curve, f(x), for a given time ▪ or a time curve, f(t), for a given abscissa ▪ or contour lines in the plane (x,t) i.e. f(x,t) In “Pollution mode", as the calculation is made in steady state regime, a physical quantity can only be viewed as a spatial curve, f(x). according to the type of display selected: ▪ either, the times for which the user wishes to view the spatial curve f(x) for one or more of the selected physical quantities ▪ i.e. the abscissas for which the user wishes to view the time curve, f(t) for one or more of the selected physical quantities



Illustration in “Fire mode”:

Illustration in “Pollution mode”:

To select several physical quantities or several times or abscissas, just click on them using the mouse while pressing the Ctrl or Maj key. The actions described in the first three points above can be performed in any order. On the other hand, the action described in the last point can only be performed after having selected the type of display for the selected physical quantities. NOTE The contour lines f(x,t) are only available for: 

air temperature



air opacity



pollutant concentration



air velocity

► Curves f(x) and f(t)

Each physical quantity is viewed in a window whose name indicates the type of display, the name of the scenario and the part of the tunnel under study. The name of the physical quantity is displayed as the title of the f(x) or f(t) curve. If the user has chosen to view the evolution of a given quantity in terms of f(t) for several abscissa or f(x) at several moments in time, all the curves are displayed on the same graph.

54

Illustration:

A right-click on the chart drawing sheet used to view the evolution of a physical quantity lets the user: 

access and modify chart properties



save the chart in *.png format



print the charts



access zoom and automatic scaling functionalities

Illustration:

right click

Chart properties can be used, in particular, to change the chart’s title and scales. Illustration:

55

► Contour lines f(x,t)

Each physical quantity is displayed in a window w whose name indicates the type de display, the name of the scenario and the part of the tunnel under study. The name of the physical quantity being viewed is displayed as the title of the contour line curve f(x,t). Illustration:

As with the f(x) and f(t) curves, a right-click on the chart’s drawing sheet lets the user: 

access and modify chart properties



save the chart in *.png format



print the charts



access automatic scaling and zoom functionalities

Illustration:

right click



The chart’s colour scale is displayed on the right of the curve. It can be modified by double-clicking on the colour scale that starts an editor. Illustration:

clic droit

dou ble click

56

Illustration:

This is used to match the chosen colours to the selected values (represented by the horizontal arrows). Colours are interpolated between two arrows. To add new values, just left-click in the desired area of the colour bar. To delete an arrow, just select it and click on the Suppr key. The arrows can also be moved using the mouse. To select the colour linked to a value (or accurately specify the value corresponding to the arrow), just double-click on the desired arrow. An editor lets the user specify the value corresponding to the colour in the “Value” field together with the corresponding colour. This can be selected from a list of basic colours, in TSL format (Hue, Saturation, Brightness) or RVB (Red, Green, Blue). Illustration:

► Viewing out-of-service jet fans

The evolution curves f(x) and f(t) can be used to display jet fan arrays qui that have been disabled due to an excessive temperature rise in a tunnel or ramp. You can do this simply by indicating it in the application preferences accessible via the “Preferences” command in the “File” menu by checking the “Display out-of-service jet fans” box.

57

Illustration:

The location of each heat-disabled jet fan array is marked on the f(x) evolution curves by an annotation that gives the name of the disabled jet fan array and the time of its disablement. Only jet fan arrays that were disabled at the selected time are notified on the f(x) evolution curve. Illustration:

On the f(t) evolution curves, each time when a jet fan array was disabled by the heat is marked by an annotation that gives the name of the array disabled at this time. Illustration:

Show traffic This command is used to view the traffic distribution in each traffic direction, according to time, in the tunnel and any related ramps for the selected scenario. The traffic distribution display window contains: 

a

button used to read traffic distribution according to time

58



a

button used to stop reading traffic distribution according to time



a

button used to view traffic distribution 1 s before the start of the fire



a

button used to view traffic distribution at the end of the simulation

Traffic distribution is viewed on a diagram representing the modelled tunnel along with any related ramps, and on which are marked: 

in green, zones where vehicles are moving normally



in red, zones where vehicles are stopped



in grey, zones free of vehicles

Illustration:

NOTE The total number of stopped vehicles is given between brackets in the key.

Export results This command is used to export, via a dialog, the results of the last calculation executed in “Fire mode” or “Pollution mode” as a *.csv file. Use the mouse to select the following elements in the dialog: 

the part of the tunnel for which the user wishes to export the results: tunnel or ramp



the physical quantity(ies) to be exported from among all the physical quantities available In “Fire mode", the quantities available are: ▪ air temperature ▪ wall temperature ▪ air opacity ▪ pollutant concentration ▪ air velocity ▪ longitudinal flow rate ▪ total pressure ▪ static pressure In “Pollution mode", the quantities available are: ▪ pollutant concentration for all the pollutants listed in the pollutants library, that can be accessed and modified using the “Pollutants” command in the “Libraries” menu ▪ air velocity ▪ longitudinal flow rate 59

the type of values to be exported



In “Fire mode", you can export: ▪ either, an table, f(x), listing the value of the physical quantity(ies) selected according to the abscissa of a given time ▪ or, a table, f(t), listing the value of the physical quantity(ies) selected according to the abscissa of a given time ▪ or, a double-entry table, f(x,t), listing the value of the physical quantity(ies) selected according to the abscissa of a given time In “Pollution mode", as the calculation is made in steady state regime, it is only possible to export a table, f(x), listing the value of the physical quantity(ies) selected according to the abscissa of a given time. according to the type of selected value to be exported: ▪ either the time(s) for which the user wishes to export an f(x) table for the physical quantity(ies) selected ▪ or the abscissa(es) for which the user wishes to export an f(t) table for the physical quantity(ies) selected



Illustration in “Fire mode”:

Illustration in “Pollution mode”:

To select several physical quantities or several times or abscissae, just select them with the mouse while pressing the Ctrl or Maj key. The actions described in the first three points above can be performed in any order. On the other hand, the action described in the last point can only be performed after having selected the type of values to be exported. NOTE The option of exporting a double-entry table f(x,t) is only available for: 

air temperature



air opacity



pollutant concentration



air velocity

Once all the elements have been selected, clicking on the generates a *.csv file containing all the requested elements.

button starts the export and

A message is displayed to notify the user that the export has been completed.

60

Illustration:

The file generated is given the name “nomScenario_typeSimu_typeExport.csv” where: 

nomScenario is the name of the selected scenario



typeSimu is the type of simulation performed ▪ Fire mode ▪ Pollution mode



typeExport is the type of export ▪ T - according to time ▪ X - according to abscissa ▪ XT - according to time and abscissa

The generated file can be opened using a text editor such as Excel or Open Office.

Export traffic results This command is used to export to a *.csv file, via a dialog, the distribution of vehicles in the tunnel and any related ramps at a given moment in time. Illustration:

This file is given the name “nomScenario_ResultatsTrafic.csv” and is saved in the “Export” folder specified in application preferences using the “Preferences” command in the “File” menu. A message is displayed to notify the user that the export has been completed. Illustration:

The generated file can be opened using a text editor such as Excel or Open Office.

61

2.2.7 “Libraries” menu The “Libraries” element in the menu bar is used to access libraries for wall materials and pollutants. Illustration:

Wall materials This command uses a dialog to list and parameter the materials that can be used for tunnel walls and any related ramps. This wall materials library is common to all the scenarios. Wall materials are chosen from the drop-down list accessed via the “Material type1” and “Material type 2” fields found in the “Tunnel sections” and “Ramps” tabs in the “Tunnel / Ramps” window in the “Parameters” menu. The wall materials library automatically contains the concrete and fire protection generally used in tunnels to improve the structure’s fire resistance. It also contains the values generally selected for the physical properties required to evaluate heat transfers with walls, i.e. their density, thermal conductivity 3 and their specific heat capacity4. Illustration:

The dialog also contains: 

a button for adding a material via a dialog used to define its name, density, thermal conductivity and specific heat capacity. Illustration:

a button used to modify the material selected and highlighted in blue with the mouse, using a dialog identical to that described above used to add a wall material.  a button used to delete the material selected and highlighted in blue with the mouse. 

A message is displayed asking the user whether they wish to delete the material from the wall materials library.

3 4

Reflects the conductive heat transfer generated by the molecular vibration of the material. Represents the amount of energy required to raise the temperature of 1 kilogram of the material by one degree Kelvin.

62

Illustration:

NOTE As with the fires library that can be accessed using the “Fire” command in the “Parameters” menu and with the pollutants library, this library is:  common to all scenarios  saved in the bdd.xml file in the .camatt/bdd folder found in the user profile folder in

Windows, or in the $HOME folder in Linux, and is therefore specific to each user All modifications or additions to this library will therefore apply to all scenarios, whether new, existing or duplicated, but will only be valid for the user that made the modification or addition.

Pollutants This command uses a dialog to list and parameter the pollutants to be studied for simulations in “ Pollution mode". This pollutants library is common to all scenarios. The list of pollutants defined in this library forms the list of accessible pollutants: 

using the button found in the various dialoges used to modify pollutant concentrations in blown air generated by an equipment or by one of the portals



using the “Pollution” command in the “Parameters” menu, which is used to modify pollutant concentrations in blown air generated by all the equipment modelled in the drawing sheet and by all the portals

The dialog contains: 

a section on gaseous pollution that automatically contains three pollutants: ▪ carbon monoxide (CO) ▪ benzene ▪ nitrogen oxides (NOx) This section also contains the molar masses of these three pollutants based on which the concentration can be expressed either in mg.m-3, or in ppm depending on the unit selected in the application preferences via the “Preferences” command in the “File” menu. You can switch from concentrations in ppm to concentrations in mg.m-3 as follows: C mg.m = −3

Mmolaire C Vmolaire ppm

avec V molaire = 24,453 l.mol 

5

−1

5

a section on particulate pollution that automatically contains the particulates class for which an air opacity of 1 m-1 corresponds to an airborne particulate concentration of 100 mg.m -3, the value suggested in CETU’s “Ventilation pilot dossier”.

Molar volume of air, assumed to be an ideal gas at 20°C and 1 atm.

63

Illustration:

For each of these two sections, the dialog also contains: 

a ▪ ▪

button for adding a gaseous pollutant or particulates class via a dialog used to defined: for gaseous pollutants, their name and molar mass for the particulates class, their name and the conversion factor to be applied in order to switch from an air opacity of 1 m-1 to a particulates concentration expressed in mg.m-3

Illustration of the addition of a gaseous pollutant:

Illustration of the addition of a particulates class:



a button for modifying the gaseous pollutant or particulates class selected and highlighted in blue with the mouse via a dialog identical to that described above used to add a gaseous pollutant or particulates class.



a button for deleting the gaseous pollutant or particulates class selected and highlighted in blue with the mouse. A message is displayed asking the user whether they wish to delete the material from the wall materials library. Illustration:

64

NOTE As with the fires library that can be accessed using the “Fire” command in the “Parameters” menu and with the wall materials library, this library is:  common to all scenarios  saved in the bdd.xml file in the .camatt/bdd folder found in the user profile folder in

Windows, or in the $HOME folder in Linux, and is therefore specific to each user All modifications or additions to this library will therefore apply to all scenarios, whether new, existing or duplicated, but will only be valid for the user that made the modification or addition.

65

2.2.8 “?” menu The “?” menu in the menu bar is used to access information on the application and on the current User Guide to the CAMATT 2.20 release. Illustration:

Help… This command provides online access to the current User Guide to the CAMATT 2.20 release in *.pdf format. This command can also be accessed by pressing the keyboard’s F1 key..

About… This command is used to access information on the application version and the Copyright. Illustration:

66

2.3 Toolbar The toolbar contains icons that provide rapid access to the main application commands. Illustration:

The list of these icons can be parametered using the “Preferences" command in the “File” menu when selecting which icons to display and which to mask. This list can contain at the most the 38 icons shown below. Illustration:

The following table describes the commands that can be accessed via the 38 icons automatically contained in the toolbar: Icon Menu

Command

File

New

File

Open

File

Save

File

Save as

File

Duplicate

File

Print preview

File

Print

Edit

Undo

Edit

Redo

Edit

Delete

Edit

Selection Mode

Edit

Zoom in

Edit

Zoom out

Edit

Zoom box

67

Icon Menu

Command

Edit

View all

Edit

Move

Edit

Grid

Edit

Group devices

Edit

Ungroup devices

Network

Tunnel

Network

Ramp

Network

Jet fan array

Network

Injector

Network

Blowing vent

Network

Extraction damper

Network

Massive extraction

Network

Local head loss

Network

Aeraulic transparency

Network

Traffic interruption

Network

Fire

Parameters

Tunnel / Ramps

Parameters

Devices

Parameters

Pressure at portals

Simulation

Fire mode

Simulation

Pollution mode

Results

Plot results

Results

Show traffic

Results

Export results

Icons remain shaded so long as the related command is inactive.

68

2.4 Drawing sheet The drawing sheet is used to model the tunnel, any related ramps, its equipment and, where applicable a fire, specific to the selected scenario. In addition to the drawing area, the drawing sheet also contains: 

a banner



a key



a scale

Illustration:

Banner

Drawing area

Scale

Legend

2.4.1 Drawing area The drawing area is the part of the drawing sheet in which are modelled the tunnels, any related ramps, equipment and, where applicable, fires. This modelling is performed using the commands in the “Network” and “Edit” menus as follows: 1) Select the “Tunnel” command in the “Network” menu and insert all the tunnel sections modelled in the drawing sheet (see pages 18 to 23) 2) If the tunnel has a ramp, select the “Ramp” command in the “Network” menu and insert all the tunnel ramps in the drawing sheet (see pages 22 to 25) 3) Select the type of equipment to be modelled using the related command in the “Network” menu and insert all equipment of this type in the drawing sheet (see pages 24 to 34) 4) Insert all the other equipment in the drawing sheet following the instructions in points 3) 5) Where applicable, select equipment of the same type that will have joint control by pressing the Ctrl key; group the equipment using the “Group devices” command in the “Edit” menu (see page 17) 6) For a simulation in “Fire mode", select the “Fire” command in the “Network” menu 7) Where applicable, insert the fire in the drawing sheet (see page 32)

69

Once the tunnel and any related ramps, plus its equipment and, where applicable, a fire, have been modelled in the drawing sheet, all the model data can be entered using the commands in the “Parameters” menu. The tunnel and any related ramps are modelled in plan view; this makes it easy to view the angle between the tunnel and the ramps.

2.4.2 Banner The banner located at the top of the drawing sheet is used to display or mask certain data in the drawing area using checkboxes: 

ramp angles



slopes of tunnel sections



tunnel orientation



devices

Ramp angle Depending on whether the box is checked or not, this command is used to display or mask the acute angle between all the ramps shown in the drawing area and the tunnel. Illustration:

Slopes of tunnel sections Depending on whether the box is checked or not, this command is used to display or mask the slopes for all tunnel sections and ramps shown in the drawing area. Illustration:

Tunnel orientation Depending on whether the box is checked or not, this command is used to display or mask the orientation of all tunnel sections and ramps shown in the drawing area that provides a reference for the positioning of equipment or fires.

70

Illustration:

Devices Depending on whether the box is checked or not, this command is used to display or mask a ll the equipment shown in the drawing area that provides a reference for the positioning of equipment or fires. Illustration:

2.4.3 Legend When building the model in the drawing area, a legend is displayed at the bottom right of the drawing sheet and is automatically updated according to the elements modelled (tunnel, ramp, equipment and fire). Illustration:

The legend is automatically displayed in the drawing sheet. However, users can mask the key using the “Preferences” command in the “File” menu if they wish.

2.4.4 Scale To facilitate the modelling process, a scale is displayed at the bottom of the drawing sheet; five grid squares automatically correspond to 200 m. This scale is then updated automatically according to the zoom selected using the related commands in the “Edit” menu. The scale is automatically displayed in the drawing sheet. However, users can mask the scale using the “Preferences” command in the “File” menu if they wish. 71

3

SOLVED EQUATIONS

The CAMATT 2.20 release solves the following physical equations governing flow: 

the equation expressing the conservation of mass



the equation expressing the conservation of the momentum in the main direction of flow



the equation expressing the conservation of enthalpy



thermodynamic equations

To these equations can be added those that govern the transport of a passive scalar in the flow used to identify a pollutant concentration in the tunnel at any moment in time.

3.1 Conservation of mass The equation expressing the conservation of mass is: ∂ ρ ∂ ρ u  =S m ∂t ∂x where ρ : air density u : air velocity S m : mass source (sink) t : time x : curvilinear abscissa along the length of the tunnel

[kg.m-3] [m.s-1] [kg.s-1.m-3] [s] [m]

The source term (or sink) of the mass S m represents the mass flow blown into or extracted from the tunnel or its ramps, if any, per unit of volume. CAMATT is used to factor in linear and local source terms (or sinks) for mass. CAMATT calculates mass sources based on: 

ambient air density



distributed blowing flow rate imposed on a section or ramp



flow rate imposed for blowing vents and injectors



pressure imposed outside aeraulic transparencies and their section when the difference between this pressure and that in the tunnel is positive

CAMATT calculates mass sinks based on: 

ambient air density for the distributed extractions and extraction dampers



air density in the tunnel for massive extractions and aeraulic transparencies



distributed extraction flow rate imposed on a section or ramp



flow rate imposed for extraction dampers and massive extractions



pressure imposed outside aeraulic transparencies and their section when the difference between this pressure and that in the tunnel is negative

3.2 Conservation of the momentum CAMATT solves the equation expressing conservation of the momentum in the direction of flow as follows: ∂Ps ∂ ρ u ∂ρ u²  =− S mvt ∂t ∂x ∂x

where ρ : air density u : air velocity Ps : static air pressure S mvt : source (or sink) for the momentum t : time

[kg.m-3] [m.s-1] [Pa] [kg.m-2.s-2 ] [s] 72

x

: curvilinear abscissa along the length of the tunnel

[m]

The momentum source term (or sink) Smvt represents the variation over time of the momentum of air per unit of volume due to the action of: 

buoyancy forces due to the buoyancy acting on hot smoke



drag (air friction) forces acting on tunnel walls



vehicle forces acting on the air



driving forces communicated to the air by jet fan arrays



driving forces communicated to the air by injectors



forces due to air drag in zones of turbulence created opposite singularities (change of section, obstacles, etc.)

The momentum source term (or sink) S mvt can therefore be described as: S mvt =∆ Pche∆ Pfrot ∆ Ppist  ∆ Pacc ∆ Pinj∆ Psing where ∆Pche : variation over time of the momentum per unit of volume due to buoyancy forces ∆Pfrot : variation over time of the momentum per unit of volume due to drag (air friction) on the tunnel walls ∆Ppist : variation over time of the momentum per unit of volume due to forces exerted by vehicles on air ∆Pacc : variation over time of the momentum per unit of volume due to driving forces communicated to the air by jet fan arrays ∆Pinj : variation over time of the momentum per unit of volume due to driving forces communicated to the by injectors ∆Psing : variation over time of the momentum per unit of volume due to drag (air friction) on zones of air turbulence

[kg.m-2.s-2 ] [kg.m-2.s-2 ] [kg.m-2.s-2 ] [kg.m-2.s-2 ] [kg.m-2.s-2 ] [kg.m-2.s-2 ]

CAMATT is used to factor in these momentum source terms (or sinks), which can be broken down into two categories: 

linear source terms (or sinks) (∆Pche, ∆Pfrot and ∆ppist)



local source terms (or sinks) (∆Pacc, ∆Pinj and ∆psing)

Local momentum source terms (or sinks) physically represent a greater number of local variations in pressure (kg.m-1.s-2) than variations in momentum per unit of volume (kg.m -2.s-2), i.e. variations in pressure per unit of length. However, a local pressure variation may be equated to a variation in pressure per unit of length by introducing the function:

{

1 1 1 si ξ ∈ [− ; ] χ ε ξ  = ε 2ε 2ε 0

Assuming that a variation in pressure ∆Pp in xp is, not local, but distributed along a length εL where ε ≪1 and L the length of a tunnel section or ramp, it can be equated to a variation in pressure per unit of length ∆Pr where: ∆ Pr=

∆ Pp x− x p χ  L ε L

Tending ε towards 0, the final equation can be written as: ∆ Pr =

∆ Pp x− xp δ  L L

where δ : Dirac’s function6

6

Defined by  f ∈ C(ℝ),

∞

∫−∞ δx f x=f 0 73

3.2.1 Linear source terms (or sinks) Buoyancy forces Buoyancy forces induce a variation over time of the momentum of air per unit of volume ( ∆Pche) that can be expressed as: ∆ Pch =−α ρ−ρ o g

[kg.m-2.s-2]

where α : slope of the tunnel section or ramp ρ : air density ρo : ambient air density g : acceleration due to gravity (= 9.81)

[-] [kg.m-3] [kg.m-3] [m.s-2]

Drag (air friction) forces on tunnel walls For each tunnel section or ramp, the air friction forces on the walls induce a variation over time of the momentum of air per unit of volume (∆Pfrot) that can be expressed as: ∆ Pfr =−λ

Π ρ u∣u∣ 4S 2

[kg.m-2.s-2]

where λ : Moody friction coefficient ρ : air density u : air velocity S : cross-section through the tunnel section or ramp Π : perimeter of the cross-section through the tunnel section or ramp

[-] [kg.m-3] [m.s-1] [m2] [m]

Vehicle forces on the air For each tunnel section and ramp, the forces exerted by vehicles on air induce a variation over time of the momentum of air per unit of volume (∆Ppist) that can be expressed as: ∆ Ppist =n

1−p C x VL ΣVL p C x PL ΣPL  ρ u−v ∣u−v∣ S

where n : number of vehicles per linear metre in the tunnel section or ramp p : percentage of HGVs in the traffic Cx VL : drag coefficient for passenger vehicles Σ VL : average frontal surface for passenger vehicles Cx PL : drag coefficient for HGVs Σ PL : average frontal surface for HGVs ρ : air density u : air velocity v : vehicle speed in the tunnel section or ramp S : cross-section through the tunnel section or ramp

[kg.m-2.s-2] [veh.m-1] [-] [veh-1] [m2] [veh-1] [m2] [kg.m-3] [m.s-1] [m.s-1] [m2]

CAMATT calculates the number of vehicles per linear metre n for each tunnel section or ramp based on: 

hourly throughput of vehicles in the tunnel section or ramp



vehicle speed in the tunnel section or ramp



inter-distance of stopped vehicles

CAMATT distinguishes two situations in order to determine traffic distribution in each tunnel section or ramp: ► Presence of a fire or a single traffic interruption

Where there is a single traffic interruption element or fire in a tunnel section or ramp, CAMATT breaks down this section or ramp into four zones per direction of traffic.

74

Illustration for a fire: spee d of tailback C zone 1

zone 2

xi

zone 3

zone 4

fire

L where xi : position of the fire L : length of the tunnel section or ramp

[m] [m]

Vehicles are circulating normally in zones 1 and 4, and are stopped in zone 2. Zone 3 is free of vehicles. The boundary between zones 1 and 2 varies over time as the traffic jam cause by a fire or traffic interruption element extends at a speed C that is calculated using the equation: C=

Q 1000 Q n− Io v

[km.h-1]

where Q : hourly throughput of vehicles in the tunnel section or ramp v : vehicle speed in the tunnel section or ramp n : number of lanes in the tunnel section or ramp Io : inter-distance between stopped vehicles

[veh.h-1] [km.h-1] [-] [m]

The boundary between zones 3 and 4 also varies over time as the presence of a fire or traffic interruption element prevents vehicles from overtaking and creates a vehicle-free zone, zone 3, which extends at the speed v of vehicles in the tunnel section or ramp. When one of these boundaries reaches the end of a section, it diffuses into the adjacent section(s) with a new speed C* or v* recalculated based on the traffic data specific to each section. ► Presence of a fire and a traffic interruption or of several traffic interruptions

Where there is a fire and one or two traffic interruption(s) in a tunnel section or ramp, CAMATT breaks down this section or ramp into seven zones per direction of traffic. At each new traffic interruption, three additional zones are added. Illustration: spee d of tailback C zone A

xb

zone B

spee d of tailback C zone C

traffic interru ption

zone D

zone E

xi

zone F

zone G

fire

L where xi : location of the fire xb : location of the traffic interruption L : length of the tunnel section or ramp

[m] [m] [m]

Clearly, zones A, B and C can only exist if the traffic interruption is activated sufficiently early. For example, in the illustration above, the condition to be complied with is: xi− x b C

t b− ti 60

where ti : start of the fire tb : time of activation of the traffic interruption C : speed of the tailback in the tunnel section or ramp

[min] [min] [km.h-1]

The boundaries between zones A and B on the one hand, and zones D and E on the other hand, vary over time as the traffic jam caused by a fire or traffic interruption element extends at a speed C. The boundaries between zones C and D on the one hand, and zones F and G on the other hand, also vary over time as a fire or traffic interruption element prevents the vehicles from overtaking and creates vehicle-free zones, zones C and F, that extend at the speed v of vehicles in the tunnel section or ramp.

75

When one of the boundaries between zones A and B or between zones F and G reaches the end of a section, it diffuses into the adjacent section(s) with a new speed C* or v* recalculated based on the traffic data specific to each section.

3.2.2 Local source terms (or sinks) Driving forces communicated to the air by a jet fan array The driving forces of air communicated by a jet fan array induce a variation over time of the momentum of air per unit of volume (∆P acc) that can be expressed as: ∆ P acc =n a k a F r

x−x a ρ u 1 1−  δ  ua Sa L L ρr

[kg.m-2.s-2]

where na : number of jet fans making up the array ka : efficiency coefficient of a jet fan Fr : free-field thrust of a jet fan at the reference temperature ρ : air density opposite the jet fan array ρ r : reference density linked to Fo u : air velocity opposite the jet fan array ua : jet fan blowing speed Sa : tunnel section or ramp opposite the jet fan array L : length of the tunnel section or ramp δ : Dirac’s function xa : abscissa of the jet fan array

[-] [-] [kg.m.s-2] [kg.m-3] [kg.m-3] [m.s-1] [m.s-1] [m2] [m] [m]

Driving forces communicated to the air by an injector The driving forces of air communicated by an injector induce a variation over time of the momentum of air per unit of volume (P inj) that can be expressed as: ∆ P inj=kinj ρo Q v inj  vinj cosα inj −u

1 Sinj L

δ

x− xinj  L

[kg.m-2.s-2]

where kinj : efficiency coefficient of the injector ρo : ambient air density Qv inj : injector flow rate vinj : injector blowing speed αinj : angle of the injector jet in relation to the tunnel axis u : air velocity directly opposite the injector Sinj : tunnel section or ramp directly opposite the injector L : length of the tunnel section or ramp δ : Dirac’s function xinj : abscissa of the injector

[-] [kg.m-3] [m.s-3] [m.s-1] [rad] [m.s-1] [m2] [m] [m]

Forces due to air drag in turbulence zones Each change of section (portal, jet fan niche, modification of transverse profile) and each obstacle found in the tunnel or ramp (traffic sign) cause airflow turbulences. Each of these singularities induces a variation over time of the momentum of air per unit of volume (∆P sing), which can be expressed as: 2

∆ Psing =−

ρs Q vs 1 x −x s ξ δ  2 s S2ref L L

[kg.m-2.s-2]

where ρs : air density directly opposite the singularity ξs : head loss coefficient of the singularity Qvs : flow rate directly opposite the singularity Sref : reference surface area linked with the singularity L : length of the tunnel section or ramp δ : Dirac’s function 76

[kg.m-3] [-] [m3.s-1] [m2] [m]

xs

: abscissa of the singularity

[m]

3.3 Conservation of enthalpy CAMATT solves the equation expressing the conservation of enthalpy as follows: ∂ ρ h ∂ρ uh  =S enth ∂t ∂x where ρ : air density h : specific enthalpy of air u : air velocity S enth : enthalpy volume source t : time x : curvilinear abscissa along the length of the tunnel

[kg.m-3] [J.kg-1] [m.s-1] [W.m-3] [s] [m]

The enthalpy source term Senth represents the variation over time of the enthalpy of air per unit of volume due to the: 

amount of heat emitted by the seat of the fire



convective heat transfers between air and walls



radiant heat transfers between smoke and walls



transfers of heat during the blowing or extraction of air

The enthalpy source term Senth can therefore be described as: S enth= ∆ Hinc ∆ Hcon ∆Hray ∆ Hins ∆ Hext where ∆Hinc : amount of heat emitted by the seat of the fire per unit of volume ∆Hcon : variation of enthalpy over time per unit of volume due to convective transfers between air and walls ∆Hray : variation of enthalpy over time per unit of volume due to radiant transfers between smoke and walls ∆Hins : variation of enthalpy over time per unit of volume due to air blowing ∆Hext : variation of enthalpy over time per unit of volume due to air extraction

[W.m-3 ] [W.m-3 ] [W.m-3 ] [W.m-3 ] [W.m-3 ]

3.3.1 Amount of heat emitted by the seat of the fire The amount of heat emitted by the seat of the fire corresponds to a local rather than a linear enthalpy source term. However, as described for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Therefore, the amount of heat emitted by the seat of a fire per unit of volume can be written as: ∆ Hinc =

2 Q˙ t x−x j δ  3 SL L

[W.m-3]

where Q˙ t : total amount of heat emitted by the seat of the fire S : tunnel section or ramp L : length of the tunnel section or ramp δ : Dirac’s function xj : abscissa of the fire

[W] [m2] [m] [m]

CAMATT assumes that only two thirds of the total amount of heat emitted by a fire is transferred to the air via convection, the other third being dissipated via direction radiation to the tunnel walls directly opposite the fire.

77

3.3.2 Convective heat transfers with walls In the presence of a fire, convective transfers between air and walls induce a variation in enthalpy over time per unit of volume that can be expressed as: ∆ H con=−

Π h T−Tp  S c

where hc =

[W.m-3]

λ C ρu 8 p 2 3



7

λ 1,0712,7Pr −1 8

where Π : perimeter of the tunnel section or ramp S : tunnel section or ramp hc : convective transfer coefficient T : air temperature Tp : wall temperature λ : Moody friction coefficient Cp : specific heat of air at constant pressure (=1000) ρ : air density u : air velocity Pr : Prandtl number for air set at 0.7

[m] [m2] [W.m-2.K-1] [K] [K] [-] [J.kg-1.K-1] [kg.m-3] [m.s-1] [-]

3.3.3 Radiant heat transfers with walls In the presence of a fire, radiant transfers between smoke, equated with a black body, and walls 8, equated with a grey body with constant emissivity, induce a variation of enthalpy over time per unit of volume that can be expressed as: ∆ H ray=−

Π h T−T p  avec S r

2

2

hr=ε o FTT p T T p 

where Π : perimeter of the tunnel section or ramp S : tunnel section or ramp hr : radiant heat transfer coefficient T : air temperature Tp : wall temperature ε : wall emissivity σo : Stefan-Boltzmann constant set at 5.68.10-8 F : shape factor

[W.m-3] [m] [m2] [W.m-2.K-1] [K] [K] [-] [W.m-2.K-4] [-]

3.3.4 Transfers of heat during air blowing Air can be blown into a tunnel or ramp by: 

distributed blowing vents



local blowing vents



injectors



aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is positive

Air can also enter the tunnel or ramp via one of its portals. The variation of enthalpy over time per unit of volume induced by blown air ∆Hins can therefore be described as:

7 8

Formula de Petukhov in a single-dimension, smoke is assumed to fill the whole tunnel section and any related ramps

78

∆ H ins= ∆ H bsr ∆ H bsp ∆ Hinj∆ H str ∆ H st where ∆Hbsr : variation of enthalpy over time per unit of volume due to air blown by distributed blowing vents ∆Hbsp : variation of enthalpy over time per unit of volume due to air blown by local blowing vents ∆Hinj : variation of enthalpy over time per unit of volume due to air blown by injectors ∆Hstr : variation of enthalpy over time per unit of volume due to air blown by aeraulic transparencies ∆Hst : variation of enthalpy over time per unit of volume due to air blown by portals

[W.m-3] [W.m-3] [W.m-3] [W.m-3] [W.m-3]

Distributed blowing vents Air blown by distributed blowing vents in a tunnel section or ramp induces a variation of enthalpy over time per unit of volume (∆Hbsr) that can be expressed as: ∆ Hbsr =

ρo Q h S v bsr bsr

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv bsr : blowing vent flow rate per unit of length hbsr : specific enthalpy in the air blown by the distributed blowing vents

[kg.m-3] [m2] 3 -1 [m .s .m-1] [J.kg1]

Local blowing vents As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by local blowing vents induces a variation of enthalpy over time per unit of volume (∆hbs) which can therefore be expressed as: ∆ Hbsp=

ρo h x− xbsp Q v bsp bsp δ   S L L

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv bsp : blowing vent flow rate hbsp : specific enthalpy in the air blown by the blowing vent L : length of the tunnel section or ramp δ : Dirac’s function xbsp : abscissa of the blowing vent

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

Injectors As with a local blowing vent, air blown by an injector induces a variation of enthalpy over time per unit of volume (∆Hi) that can be expressed as: ∆ Hinj=

ρo h x− xinj Q v inj inj δ   S L L

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv inj : blowing injector flow rate hinj : specific enthalpy of injector blown air L : length of the tunnel section or ramp δ : Dirac’s function xinj : abscissa of the injector

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

Aeraulic transparencies In contrast to local or distributed blowing vents and injectors, an aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is 79

positive. In this case, air blown by an aeraulic transparency induces a variation of enthalpy over time per unit of volume (Hstr) that can be expressed as: ∆ Hstr=



ρo 2∣Pt −Pe∣ hstr x−x tr Str δ  S L L ξtr ρ o

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Pt : tunnel air pressure directly opposite aeraulic transparency Pe : imposed air pressure outside the aeraulic transparency ξtr : head loss coefficient of the aeraulic transparency set at 1.5 Str : cross-section of the aeraulic transparency hstr : specific enthalpy of air blown by the aeraulic transparency L : length of the tunnel section or ramp δ : Dirac’s function xtr : abscissa of the aeraulic transparency

[kg.m-3] [m2] [Pa] [Pa] [-] [m2] [J.kg1] [m] [m]

Air entering via the portals Air entering a tunnel section or ramp via the portals induces a variation of enthalpy over time per unit of volume (∆Hst) that can be expressed as: ∆ Hst =

ρo h x−xst Q v st st δ  S L L

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv st : flow rate entering via a portal hst : specific enthalpy of air entering via a portal L : length of the tunnel section or ramp δ : Dirac’s function xst : abscissa of the portal

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

3.3.5 Transfers of heat during air extraction Air can be extracted from a tunnel or ramp by: 

distributed extraction dampers



local extraction dampers



massive extraction



aeraulic transparency, when the difference between the pressure imposed outside and that in the tunnel is negative

Air can also escape from a tunnel or ramp via one of its portals. The variation of enthalpy over time per unit of volume induced by air extraction ∆hext can therefore be described as: ∆ H ext=∆ H ter ∆ H tep ∆ Hem ∆ H etr ∆ H et where ∆Hter : variation of enthalpy over time per unit of volume due to air extracted by distributed extraction dampers ∆Htep : variation of enthalpy over time per unit of volume due to air extracted by local extraction dampers ∆Hem : variation of enthalpy over time per unit of volume due to air extracted by massive extractions ∆Hetr : variation of enthalpy over time per unit of volume due to air extracted by aeraulic transparencies ∆Het : variation of enthalpy over time per unit of volume due to air extracted via portals

80

[W.m-3] [W.m-3] [W.m-3] [W.m-3] [W.m-3]

Distributed extraction dampers Air extracted by distributed extraction dampers in a tunnel section or ramp induces a variation of enthalpy over time per unit of volume (∆Hter) that can be expressed as: ρo Q h S v etr ter

∆ Hter =−

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv ter : extraction damper flow rate per unit of length hter : specific enthalpy of air extracted by distributed extraction dampers

[kg.m-3] [m2] 3 -1 [m .s .m-1] [J.kg1]

Local extraction dampers As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by a local extraction damper induces a variation of enthalpy over time per unit of volume (∆hes) which can be expressed as: ∆ Htep =−

ρo h x −xtep Q v tep tep δ   S L L

[W.m-3]

where ρo : ambient air density S : tunnel section or ramp Qv tep : extraction damper flow rate htep : specific enthalpy of air extracted by an extraction damper L : length of the tunnel section or ramp δ : Dirac’s function xtep : abscissa of the extraction damper

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

Massive extractions As with an extraction damper, air extracted by massive extraction induces a variation of enthalpy over time per unit of volume (Hem) that can be expressed as: ∆ Hem=−

ρ em hem x− xem Q δ  S v em L L

[W.m-3]

where ρem : air density directly opposite the massive extraction S : tunnel section or ramp Qv em : massive extraction flow rate hem : specific enthalpy of air extracted by massive extraction L : length of the tunnel section or ramp δ : Dirac’s function xem : abscissa of massive extraction

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

Aeraulic transparencies In contrast to local or distributed extraction dampers and injectors, an aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is negative. In this case, air extracted by an aeraulic transparency induces a variation of enthalpy over time per unit of volume (∆Hetr) that can be expressed as: ∆ Hstr=− where ρtr S Pt Pe ξtr Str hetr



ρ tr 2∣Pt −Pe∣ h etr x −x tr Str δ  S L L ξtr ρ tr

[W.m-3]

: Air density opposite the aeraulic transparency : tunnel section or ramp : tunnel air pressure directly opposite aeraulic transparency : imposed air pressure outside the aeraulic transparency : head loss coefficient of the aeraulic transparency set at 1,5 : section of the aeraulic transparency : specific enthalpy of air extracted by aeraulic transparency 81

[kg.m-3] [m2] [Pa] [Pa] [-] [m2] [J.kg1]

L δ xtr

: length of the tunnel section or ramp : Dirac’s function : abscissa of the aeraulic transparency

[m] [m]

Air exiting via the portals Air exiting from a tunnel section or ramp via a portal induces a variation of enthalpy over time per unit of volume (∆Het) that can be expressed as: ∆ Het=− where ρet S Qv et het L δ xet

ρ et het x−x et Q δ  S v et L L

[W.m-3]

: air density at the portal : tunnel section or ramp : portal exit flow rate : specific enthalpy of air exiting via the portal : length of the tunnel section or ramp : Dirac’s function : abscissa of the portal

[kg.m-3] [m2] 3 -1 [m .s ] [J.kg1] [m] [m]

3.4 Heating of walls The heat flows transferred with tunnel walls via convection and radiation (∆Hcon and ∆Hray) factor in the heating of walls due to conductive heat transfers within the structure and their impact on airflow in the tunnel. This heating of walls is factored in using Fourier’s equation which is also solved by CAMATT: 2

ρs C ps

∂T s  ∂  Ts  λ s =0 ∂t ∂ z2

where ρs : density of wall materials Cps : specific heat of wall materials Ts : temperature of the structure at depth z λs : thermal conductivity of wall materials t : time z : depth

[kg.m-3 ] [J.kg-1.K-1 ] [K] [W.m-1.K-1 ] [s] [m]

CAMATT is used to factor in walls made of two different materials at the most. It therefore solves Fourier’s equation using equivalent thermo-physical properties that are calculated as follows: ρs =p mat 1 ρs1 1−pmat 1 ρs2 C ps=p mat 1 Cps11−p mat 1 C ps2 λ s=p mat 1 λ s11−pmat 1 λ s2

where pmat 1 : proportion of material 1 to material 2 ρs1 : density of wall material 1 ρs2 : density of wall material 2 Cps1 : specific heat of wall material 1 Cps2 : specific heat of wall material 2 λs1 : thermal conductivity of wall material 1 λs2 : thermal conductivity of wall material 2

[-] [kg.m-3 ] [kg.m-3 ] [J.kg-1.K-1 ] [J.kg-1.K-1 ] [W.m-1.K-1 ] [W.m-1.K-1 ]

To solve Fourier’s equation, CAMATT considers that the tunnel section or ramp is an annular section with thickness16 cm comprising 8 concentric rings:

82

Ring thickness 1

07 mm

2

10 mm

3

12 mm

4

15 mm

5

20 mm

6

25 mm

At each ring i, CAMATT links a mean temperature for the structure Tsai calculated using Fourier’s equation. The limit conditions factored in by CAMATT are given below: 

no conductive heat transfer beyond a depth of 16 cm



conservation of heat flows at the interface between the air and the tunnel wall that can be expressed as: hch r T−Tp =2 λ s

T p−T sa1 ea1

where hc : convective transfer coefficient hr : radiant heat transfer coefficient T : air temperature Tp : wall temperature λs : thermal conductivity of the material making up the structure Tsa1 : mean temperature of the wall’s first ring ea1 : thickness of the first ring set at 7.10-3

[W.m-2.K-1] [W.m-2.K-1] [K] [K] [W.m-1.K-1] [K] [m]

3.5 Thermodynamic equations CAMATT solves the following thermodynamic equations:

3.5.1 Equation of state The air in the tunnel is equated to a perfect incompressible gas. Its density is therefore assumed to depend solely on variations in temperature, and not on variations in pressure, which are deemed too small with respect to atmospheric pressure. CAMATT therefore solves the perfect gas equation as follows: ρ T=

MPo R

where ρ : air density T : air temperature M : molar mass of air Po : atmospheric pressure set at 101 325 R : perfect gas constant set at 8.315

[kg.m-3] [K] [kg.mol-1] [Pa] [J.mol-1.K-1]

CAMATT only uses this equation to calculate air densityρ and its temperature T.

3.5.2 Specific enthalpy The air in the tunnel is equated to a perfect gas. Its specific enthalpy therefore depends solely on its temperature, and not on variations in pressure, which are deemed too small with respect to atmospheric pressure. In addition, the specific heat of air at constant pressure varies very little with respect to the temperatures that may be encountered in a tunnel following a fire.

83

CAMATT therefore solves the equation linking specific enthalpy to air temperature as follows: h=Cp T

where h : specific enthalpy of air Cp : specific heat of air at constant pressure set at 1 000 T : air temperature

[J.kg-1] [J.kg-1.K-1] [K]

This equation is used to solve the conservation of enthalpy equation.

3.6 Transport of a passive scalar A passive scalar is a physical quantity that is simply subject to transport phenomena, without effecting flow behaviour. CAMATT is used to factor in two types of passive scalar: gaseous pollutant concentrations and air opacity.

3.6.1 Gaseous pollutants In “Fire mode", CAMATT solves the equation expressing in-flow gaseous pollutant transport as follows: ∂ cp  ∂ucp   =S p ∂t ∂x where cp : concentration of gaseous pollutant in air u : air velocity S p : mass source (or sink) of the gaseous pollutant t : time x : curvilinear abscissa along the length of the tunnel

[kg.m-3] [m.s-1] [kg.m-3.s-1] [s] [m]

In “Pollution mode", this equation is solved in steady state regime, and therefore becomes: ∂ u c p  =S p ∂x The mass source term (or sink) for a gaseous pollutant S pol represents the variation over time of the mass of the gaseous pollutant per unit of volume that takes account of: 

gaseous pollutants emitted by the seat of a fire in “Fire mode"



gaseous pollutants emitted by road traffic in “Pollution mode"



gaseous pollutants blown into a tunnel or ramp by: ▪ distributed blowing vents ▪ local blowing vents ▪ injectors ▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is positive



gaseous pollutants extracted from a tunnel or ramp by: ▪ distributed extraction dampers ▪ local extraction dampers ▪ massive extractions ▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is negative



gaseous pollutants entering the tunnel or ramp via a portal



gaseous pollutants exiting the tunnel or ramp via a portal

The variation over time of the mass of a gaseous pollutant per unit of volume can therefore be written as: S p=S p eS p bsr S p ter S p bsp S p tep S p injSp em S p str S p etr S p st S p et where Sp e : variation over time of the mass of the pollutant per unit of volume due to emissions in the tunnel Sp bsr : variation over time of the mass of the pollutant per unit of volume due to air blown by distributed blowing vents 84

[kg.m-3.s-1] [kg.m-3.s-1]

Sp ter : variation over time of the mass of the pollutant per unit of volume due to air extracted by distributed extraction dampers Sp bsp : variation over time of the mass of the pollutant per unit of volume due to air blown by local blowing vents Sp tep : variation over time of the mass of the pollutant per unit of volume due to air extracted by local extraction dampers Sp inj : variation over time of the mass of the pollutant per unit of volume due to air blown by injectors Sp em : variation over time of the mass of the pollutant per unit of volume due to air extracted by massive extraction Sp str : variation over time of the mass of the pollutant per unit of volume due to air blown by aeraulic transparencies Sp etr : variation over time of the mass of the pollutant per unit of volume due to air extracted by aeraulic transparencies Sp st : variation over time of the mass of the pollutant per unit of volume due to air entering via the portals Sp et : variation over time of the mass of the pollutant per unit of volume due to air exiting via the portals

[kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1] [kg.m-3.s-1]

For calculations in “Fire mode", the gaseous pollutant factored in for fires is carbon monoxide (CO); however, it is possible to factor in another pollutant by changing the pollutant emission flow rate value.

Emissions of gaseous pollutants from the seat of a fire Emissions of CO from the seat of a fire correspond to a local rather than a linear mass source term. However, as specified for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. The CO mass source term for the seat of a fire per unit of volume (Sp e) can therefore be written as: Sp e =

Qm CO x−xj δ  SL L

[kg.m-3.s-1]

where Qm CO : mass flow of CO emitted by the seat of the fire S : tunnel section or ramp L : length of the tunnel δ : Dirac’s function xj : abscissa of the fire

[kg.s-1] [m2] [m] [m]

Emissions of gaseous pollutants by road traffic Emissions of gaseous pollutants by road traffic are only factored in for calculations in “Pollution mode” as they are negligible with respect to emissions from the seat of a fire. The road traffic found in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp e) that can be expressed as: Sp e =

ep S

[kg.m-3.s-1]

where ep : mass flow of the gaseous pollutant per unit of length emitted by road traffic S : tunnel section or ramp

[kg.s-1.m-1] [m2]

Distributed blowing vents Air blown by distributed blowing vents in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp bsr) that can be expressed as: Sp bsr=

cop bsr Q v bsr S

[kg.m-3.s-1]

where cop bsr : concentration of the gaseous pollutant in air blown by distributed blowing vents S : tunnel section or ramp Qv bsr : blowing vent flow rate per unit of length

85

[kg.m-3] [m2] 3 -1 [m .s .m-1]

Distributed extraction dampers Air extracted by distributed extraction dampers in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (S p ter) that can be expressed as: Sp ter =−

cp Q S v ter

[kg.m-3.s-1]

where cp : concentration of the gaseous pollutant in air extracted by distributed extraction dampers [kg.m-3] S : tunnel section or ramp [m2] 3 -1 Qv ter : extraction damper flow rate per unit of length [m .s .m-1]

Local blowing vents As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by a local blowing vent induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp bsp) that can be expressed as: Sp bsp=

cop bsp 1 x −x bsp Q v bsp δ   S L L

[kg.m-3.s-1]

where cop bsp : concentration of the gaseous pollutant in air blown by a blowing vent S : tunnel section or ramp Qv bsp : blowing vent flow rate δ : Dirac’s function xbsp : abscissa of the blowing vent

[kg.m-3] [m2] 3 -1 [m .s ] [m]

Local extraction dampers As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by an extraction damper induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp tep) that can be expressed as: Sp tep=−

cp 1 x −x tep Q δ  S v tep L L

[kg.m-3.s-1]

where cp : concentration of the gaseous pollutant in air extracted by extraction damper S : tunnel section or ramp Qv tep : extraction damper flow rate δ : Dirac’s function xtep : abscissa of the extraction damper

[kg.m-3] [m2] 3 -1 [m .s ] [m]

Injectors As with a local blowing vent, air blown by an injector induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp inj) that can be expressed as: Sp inj=

c op inj 1 x −x inj Q v inj δ   S L L

[kg.m-3.s-1]

where cop inj : concentration of the gaseous pollutant in air blown by the injector S : tunnel section or ramp Qv inj : injector flow rate δ : Dirac’s function xinj : abscissa of the injector

[kg.m-3] [m2] 3 -1 [m .s ] [m]

Massive extractions As with a local extraction damper, air extracted by a massive extraction induces for each gaseous pollutant a variation over time of its mass per unit of volume (S p em) that can be expressed as:

86

Sp em=−

cp 1 x−x em Q v em δ   S L L

[kg.m-3.s-1]

where cp : concentration of the gaseous pollutant in air extracted by massive extraction S : tunnel section or ramp Qv em : massive extraction flow rate δ : Dirac’s function xem : abscissa of the massive extraction

[kg.m-3] [m2] 3 -1 [m .s ] [m]

Aeraulic transparencies An aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is positive. In this case, air blown by the aeraulic transparency induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp str) that can be expressed as: Sp str=



cop tr 2∣Pt −Pe∣ 1 x−x tr Str δ   S L L ξ tr ρo

[kg.m-3.s-1]

where cop tr : concentration of the gaseous pollutant in air blown by the aeraulic transparency S : tunnel section or ramp Pt : tunnel air pressure opposite the aeraulic transparency Pe : imposed air pressure outside the aeraulic transparency ξtr : head loss coefficient of the aeraulic transparency set at 1.5 L : length of the tunnel section or ramp δ : Dirac’s function xtr : abscissa of the aeraulic transparency

[kg.m-3] [m2] [Pa] [Pa] [-] [m] [m]

In other cases, air extracted by the aeraulic transparency induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp etr) that can be expressed as: Sp str=−



cp 2∣Pt −Pe∣ 1 x− xtr Str δ   S L L ξ tr ρ tr

[kg.m-3.s-1]

where cp : concentration of the gaseous pollutant in air extracted by an aeraulic transparency

[kg.m-3]

Air entering via the portals Air entering a tunnel section or ramp via a portal induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp st) that can be expressed as: Sp st =

c op st 1 x−x st Qv st δ  S L L

[kg.m-3.s-1]

where cop st : concentration of the pollutant in air entering via a portal S : tunnel section or ramp Qv st : flow rate entering via a portal L : length of the tunnel section or ramp δ : Dirac’s function xst : abscissa of the portal

[kg.m-3] [m2] 3 -1 [m .s ] [m] [m]

Air exiting via the portals Air exiting from a tunnel section or ramp via a portal induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp and) that can be expressed as: Sp et=−

cp 1 x−x et Q v et δ   S L L

[kg.m-3.s-1]

avec where cp : concentration of the gaseous pollutant in air exiting via a portal 87

[kg.m-3]

S Qv et L δ xet

[m2] [m3.s-1] [m]

: tunnel section or ramp : flow rate exiting via a portal : length of the tunnel section or ramp : Dirac’s function : abscissa of the portal

[m]

3.6.2 Air opacity For soot and particulate matter, the passive scalar selected in CAMATT is air opacity quantified through the extinction coefficient9 that represents the relative loss in luminous flux per unit of length. In “Fire mode”, CAMATT solves the equation expressing the transport of opacity in the flow as follows: ∂ k ∂ u k  =S k ∂t ∂x where k : extinction coefficient for air u : air velocity S p : opacity source (or sink) t : time x : curvilinear abscissa along the length of the tunnel

[m-1] [m.s-1] [m-1.s-1] [s] [m]

In “Pollution mode", this equation is solved in steady state regime and therefore becomes: ∂ u k =S k ∂x The opacity source term (or sink) S k represents the variation over time of opacity that factors in: 

soot emitted by the seat of a fire in “Fire mode"



particulates emitted by road traffic in “Pollution mode"



particulates blown into the tunnel or ramp by: ▪ distributed blowing vents ▪ local blowing vents ▪ injectors ▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is positive



particulates extracted from the tunnel or ramp by: ▪ distributed extraction dampers ▪ local extraction dampers ▪ massive extractions ▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is negative



particulates entering the tunnel or ramp via a portal



particulates exiting the tunnel or ramp via a portal

The variation over time of opacity can therefore be written as: S k=S k eS k bsrS k ter S k bspS k tepS k injSk emS k str S k etr S k stS k st where Sk e : variation over time of opacity due to emissions in the tunnel Sk bsr : variation over time of opacity due to air blown by distributed blowing vents Sk ter : variation over time of opacity due to air extracted by distributed extraction dampers Sk bsp : variation over time of opacity due to air blown by local blowing vents Sk tep : variation over time of opacity due to air extracted by local extraction dampers

9

Also referred to as the optical absoption coefficient

88

[m-1.s-1] [m-1.s-1] [m-1.s-1] [m-1.s-1] [m-1.s-1]

Sk inj : variation over time of opacity due to air blown by injectors Sk em : variation over time of opacity due to air extracted by massive extractions Sk str : variation over time of opacity due to air blown by aeraulic transparencies Sk etr : variation over time of opacity due to air extracted by aeraulic transparencies Sk st : variation over time of opacity due to air entering via the portals Sk and : variation over time of opacity due to air exiting via the portals

[m-1.s-1] [m-1.s-1] [m-1.s-1] [m-1.s-1] [m-1.s-1] [m-1.s-1]

Emissions of soot from the seat of a fire Emissions of soot from the seat of a fire correspond to a local rather than a linear mass source term. However, as specified for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. The opacity source term for the seat of a fire (Sk e) can therefore be written as: Sk e=

Φk x− xj δ  SL L

[m-1.s-1]

where Φk : opacity flux emitted by the seat of the fire S : tunnel section or ramp L : length of the tunnel δ : Dirac’s function xj : abscissa of the fire

[m3.s-1.m-1 ] [m2] [m] [m]

Emissions of particulates from road traffic Emissions of particulates from road traffic are only factored in for calculations in “ Normal extraction mode” as they are negligible with respect to emissions of soot from the seat of a fire. The road traffic found in a tunnel section or ramp induces a variation over time of opacity (S k e) that can be expressed as: Sk e=

α ek S

[m-1.s-1]

where α : unit conversion factor ek : mass flow in particulates per unit of length of road traffic S : tunnel section or ramp

[m-1.kg-1.m3] [kg.s-1.m-1] [m2]

Distributed blowing vents Air blown by distributed blowing vents in a tunnel section or ramp induces a variation over time of opacity (Sk bsr) that can be expressed as: Sk bsr=

ko bsr Q v bsr S

[m-1.s-1]

where ko bsr : extinction coefficient for air blown by distributed blowing vents S : tunnel section or ramp Qv bsr : blowing vent flow rate per unit of length

[m-1] [m2] [m3.s-1.m-1]

Distributed extraction dampers Air extracted by distributed extraction dampers in a tunnel section or ramp induces a variation over time of opacity (Sk ter) that can be expressed as: k Sk ter =− Q v ter S

[m-1.s-1]

89

where k : extinction coefficient of air S : tunnel section or ramp Qv ter : extraction damper flow rate per unit of length

[m-1] [m2] 3 -1 [m .s .m-1]

Local blowing vents As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by a local blowing vent induces a variation over time of opacity (S k bsp) that can be expressed as: Sk bsp=

k o bsp 1 x −xbsp Q v bsp δ  S L L

[m-1.s-1]

where ko bsp : extinction coefficient for air blown by a blowing vent S : tunnel section or ramp Qv bsp : blowing vent flow rate δ : Dirac’s function xbsp : abscissa of the blowing vent

[m-1] [m2] 3 -1 [m .s ] [m]

Local extraction dampers As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by an extraction damper induces a variation over time of opacity (S k tep) that can be expressed as: Sk tep=−

k 1 x−x tep Q v tep δ   S L L

[m-1.s-1]

where k : extinction coefficient of air S : tunnel section or ramp Qv tep : extraction damper flow rate δ : Dirac’s function xtep : abscissa of the extraction damper

[m-1] [m2] 3 -1 [m .s ] [m]

Injectors As with a local blowing vent, air blown by an injector induces a variation over time of opacity (S k inj) that can be expressed as: Sk inj= where ko inj S Qv inj δ xinj

k o inj 1 x−xinj Q v inj δ   S L L

[m-1.s-1]

: extinction coefficient in injector blown air : tunnel section or ramp : injector flow rate : Dirac’s function : abscissa of the injector

[m-1] [m2] 3 -1 [m .s ] [m]

Massive extractions As with local extraction dampers, air extracted via massive extraction induces a variation over time of opacity (Sk em) that can be expressed as: Sk em=−

k 1 x− xem Qv em δ   S L L

[m-1.s-1]

where k : extinction coefficient of air S : tunnel section or ramp Qv em : massive extraction flow rate δ : Dirac’s function xem : abscissa of the massive extraction

[m-1] [m2] 3 -1 [m .s ] [m] 90

Aeraulic transparencies An aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is positive. In this case, air blown by the aeraulic transparency induces a variation over time of opacity (S k str) that can be expressed as: Sk str=



k o tr 2∣Pt −Pe∣ 1 x−xtr Str δ  S L L ξ tr ρo

[m-1.s-1]

where ko tr : extinction coefficient in the aeraulic transparency blown air S : tunnel section or ramp Pt : tunnel air pressure directly opposite an aeraulic transparency Pe : imposed air pressure outside an aeraulic transparency ξtr : head loss coefficient of the aeraulic transparency set at 1.5 L : length of the tunnel section or ramp δ : Dirac’s function xtr : abscissa of the aeraulic transparency

[m-1] [m2] [Pa] [Pa] [-] [m] [m]

In other cases, air extracted via aeraulic transparency induces a variation over time of opacity (S p etr) that can be expressed as: Sk str=−



k 2∣Pt −Pe∣ 1 x −xtr Str δ   S L L ξtr ρ tr

[m-1.s-1]

where k : extinction coefficient of air

[m-1]

Air entering via the portals Air entering a tunnel section or ramp via a portal induces a variation over time of opacity (S k st) that can be expressed as: Sk st =

k o st 1 x −x st Q δ  S v st L L

[m-1.s-1]

where ko tr : extinction coefficient of air entering via a portal S : tunnel section or ramp Qv st : flow rate entering via a portal L : length of the tunnel section or ramp δ : Dirac’s function xst : abscissa of the portal

[m-1] [m2] [m3.s-1] [m] [m]

Air exiting via the portals Air exiting from a tunnel section or ramp via a portal induces a variation over time of opacity (S k and) that can be expressed as: Sk et=− where k S Qv et L δ xet

k 1 x− x et Qv et δ   S L L

[m-1.s-1] [m-1] [m2] 3 -1 [m .s ] [m]

: extinction coefficient of air : tunnel section or ramp : flow rate exiting via a portal : length of the tunnel section or ramp : Dirac’s function : abscissa of the portal

[m]

91

92

CONTRIBUTORS Frédéric VINCENT, Xavier PONTICQ, Antoine MOS and Jean-François BURKHART participated in the drafting of this document.

93

Tunnels Study Centre 25, avenue François Mitterrand Case n°1 69674 BRON - FRANCE Tél. 33 (0)4 72 14 34 00 Fax. 33 (0)4 72 14 34 30 [email protected]

www.cetu.developpement-durable.gouv.fr