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Sports and Building Aerodynamics by Bert Blocken Week 1: Basic aspects of fluid flow 1. 2.

Fluid properties - part 1 (velocity, pressure, temperature) Fluid properties - part 2 (density)

3. 4.

Fluid properties - part 3 (viscosity) Flow properties - part 1

5. 6.

Flow properties - part 2 Fluid statics, kinematics, dynamics

7. 8.

Boundary layers - part 1 Boundary layers - part 2

9. 10.

Boundary layers - part 3 The atmospheric boundary layer

Week 2: Wind-tunnel testing 1.

Why wind-tunnel testing?

2. 3.

Wind-tunnel types and applications The atmospheric boundary layer wind tunnel

4. 5.

Wind-tunnel components Measurements and flow visualization

6. 7.

Similarity and flow quality Best practice guidelines

Week 3: Computational Fluid Dynamics 1.

Computational Fluid Dynamics: what, why and how?

2. 3.

Approximate forms of the Navier-Stokes equations Turbulence modeling

4. 5.

Some aspects of discretization Near-wall modeling

6.

Errors and uncertainty, verification and validation

7. 8.

Best practice guidelines Computational Wind Engineering – Part 1

9.

Computational Wind Engineering – Part 2

Week 4: Building aerodynamics 1. 2.

Wind flow around buildings – part 1 Wind flow around buildings – part 2

3. 4.

Pedestrian-level wind conditions around buildings – part 1 Pedestrian-level wind conditions around buildings – part 2

5. 6.

Pedestrian-level wind conditions around buildings – part 3 Natural ventilation of buildings

7.

Wind-driven rain on building facades – part 1

8. 9.

Wind-driven rain on building facades – part 2 Wind energy in the built environment – part 1

10.

Wind energy in the built environment – part 2

Week 5: 100 m sprint aerodynamics 1.

Why study sprint aerodynamics?

2. 3.

Mathematical-physical model of running Wind effects

4. 5.

Altitude effects Stadium aerodynamics and sprint records

6.

Interview with a professional athletics coach

Week 6: Cycling aerodynamics 1. 2.

Why study cycling aerodynamics? Wind-tunnel testing for a single cyclist – Part 1

3.

Wind-tunnel testing for a single cyclist – Part 2

4.

CFD simulations for a single cyclist

5. 6.

Aerodynamics of two drafting cyclists Aerodynamics of drafting cyclist groups

7. 8.

Aerodynamics of car-cyclist combinations Interview with professional cycling coaches from teams Belkin and RaboLiv

Part 1 training will be repeated twice on May 13 at 6.30 am (Argentina). Part 2 training will be repeated twice on May 15 at 6.30 am (Argentina).

For any further information, please contact [email protected]

Elsevier articles describing part of MOOC contents now freely accessible by these links

Dear MOOC Participants Elsevier has been so kind to provide a large number of articles that match directly with several modules of the MOOC in Open Access especially for the MOOC Participants. You find the links below, along with the corresponding weeks. I would like to take this opportunity to express my special thanks to Elsevier and to Laura Ballu and her team at Elsevier-Oxford for creating these links for us and for their support for this MOOC. There are short links, and also long links, in case the short links would give a problem. Two of these articles will also be the subject of the peer-graded assignment. These are labeled below with "***ASSIGNMENT***" Best regards Bert

WEEK 3 ON COMPUTATIONAL FLUID DYNAMICS Solari, G. 2007. The International Association for Wind Engineering (IAWE): Progress and prospects. Journal of Wind Engineering and Industrial Aerodynamics 95: 813-842.

http://www.sciencedirect.com/science/article/pii/S0167610507000207

http://bit.ly/1gb2IZu

Blocken B. 2014. 50 years of Computational Wind Engineering: Past, present and future. Journal of Wind Engineering and Industrial Aerodynamics 129: 69-102.

http://www.sciencedirect.com/science/article/pii/S016761051400052X http://bit.ly/SD94M7

Blocken B, Stathopoulos T, Carmeliet J. 2007. CFD simulation of the atmospheric boundary layer: wall function problems.Atmospheric Environment 41(2): 238-252.

http://www.sciencedirect.com/science/article/pii/S135223100600834X http://bit.ly/1fYrf9s

Ramponi R, Blocken B. 2012. CFD simulation of cross-ventilation for a generic isolated building: impact of computational parameters. Building and Environment 53: 34-48

http://www.sciencedirect.com/science/article/pii/S0360132312000133 http://bit.ly/1otaqDo

WEEK 4 ON BUILDING AERODYNAMICS Blocken B, Janssen WD, van Hooff T. 2012. CFD simulation for pedestrian wind comfort and wind safety in urban areas: General decision framework and case study for the Eindhoven University campus. Environmental Modelling & Software30: 15-34.

http://www.sciencedirect.com/science/article/pii/S1364815211002647 http://bit.ly/1uF2OBW

van Hooff T, Blocken B, 2010. On the effect of wind direction and urban surroundings on natural ventilation of a large semi-enclosed stadium. Computers & Fluids 39: 1146-1155. **** ASSIGNMENT ****

http://www.sciencedirect.com/science/article/pii/S0045793010000460 http://bit.ly/1mFGWAS

van Hooff T, Blocken B, Aanen L, Bronsema B. 2011. A venturi-shaped roof for wind-induced natural ventilation of buildings: wind tunnel and CFD evaluation of different design configurations. Building and Environment 46(9): 1797-1807.

http://www.sciencedirect.com/science/article/pii/S0360132311000576 http://bit.ly/1kQGddC

WEEK 6 ON CYCLING AERODYNAMICS Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J. 2010. Aerodynamic study of different cyclist positions: CFD analysis and full-scale wind-tunnel tests. Journal of Biomechanics 43(7): 1262-1268.

http://www.sciencedirect.com/science/article/pii/S002192901000059X http://bit.ly/1m1qg8m

Blocken B, Defraeye T, Koninckx E, Carmeliet J, Hespel P. 2013. CFD simulations of the aerodynamic drag of two drafting cyclists. Computers & Fluids 71: 435-445. **** ASSIGNMENT ****

http://www.sciencedirect.com/science/article/pii/S0045793012004446 http://bit.ly/1jiSknq

Thu 8 May 2014 8:30 AM PDT

CORRECTED LINKS: 3 conferences on Building Aerodynamics including Sports Aerodynamics

Please see below the announcement of three conferences in Building Aerodynamics, also including Sports Aerodynamics (now with corrected links). You are very welcome! Best regards Bert

CWE2014 6th Symposium on Computational Wind Engineering June 8-12, 2014, Hamburg, Germany http://www.cwe2014.org/

IN-VENTO-2014 13th Conference of the Italian Association of Wind Engineering June 22-25, 2014, Genova, Italy http://www.invento2014.org/

EEBP7 7th International Symposium on Environmental Effects on Buildings and People - Actions, Influences, Interactions, Discomfort October 20-22, 2014, Cracow, Poland http://psiw.org.pl/eebp7/ Wed 7 May 2014 5:00 AM PDT

Tomorrow: special input by em.prof. Robert Meroney based on his 50 years of experience!

Dear Participants Special announcement. Emeritus Professor Robert N. Meroney, one of the most prominent researchers in the history of Wind Engineering, told me he has been watching this MOOC and he has kindly agreed to provide some material especially for the participants of this MOOC. This material is of extra-ordinary value, and you will receive it tomorrow. Em. Prof. R.N. Meroney and Em. Prof. S. Murakami are internationally recognized as the founding fathers of Computational Wind Engineering, as will be explained in week 3, modules 8 and 9, of this MOOC. Em. Prof. Robert N. Meroney and his team provided many pioneering achievements, especially related to the combination of high-quality CFD simulations with high-quality windtunnel testing for validation of those CFD simulations. This was the ground-breaking approach that is now followed by wind engineering researchers around the world, and it has been set as a standard for acceptance of CFD work in international scientific journals. These early and exceptionally valuable contributions have been published in a large amount of papers that you can download from this website: http://www.engr.colostate.edu/~meroney/ Please stay tuned to receive more input from Em. Prof. R.N. Meroney tomorrow. Very many thanks to Prof. Meroney for his contribution to this MOOC. Best regards Bert

Tue 6 May 2014 4:00 PM PDT

Question to all participants: which wind energy roof works, and which is useless?

Wind energy in the built environment is a hot topic. This leads many inventors to try to establish a break-through in this field. Sometimes based on good ideas, but - unfortunately - more often based on wrong intuition, leading to designs that do not work very well, or do not work at all. Four years ago, my research team was asked to analyze the performance of a wind energy roof. In this roof, a wind turbine is positioned in the middle of the roof, and the roof is shaped as a "venturi-channel", intended to substantially increase the wind speed in the narrowest part of the contraction. See figure 1 and 2. The designer at that time provided two designs, one with 4 vertical guiding vanes and one with 36 vertical guiding vanes in the roof (see figures 3b and 3c). The vanes were intended to accelerate the flow towards the center of the roof - where the wind turbine would be positioned - by the so-called Venturi effect. We added two extra configurations to the analysis: a design without vertical guiding vanes (see figure 3a; of course the top part of this roof is not floating but will be supported by slender columns which were not in the CFD simulation) and a reference case (see figure 3d: a regular roof, without disk-shaped construction above it). So the questions for discussion here are: 1) Which configuration do you think is the best? 2) Which configuration do you think will not work at all? I can already tell that the configuration in figure 3b is now commercially sold and that it won quite a lot of national prizes in the Netherlands. Please feel free to share your thoughts, and, most important... be critical! Closure is provided in week 4, module 9. Looking forward to your thoughts Best regards Bert

FIGURE 1

FIGURE 2

FIGURE 3

Tue 6 May 2014 12:00 PM PDT

Nomenclature & glossary Dear Participants The nomenclature and glossary are now available. I will post a thread on the forum where you can suggest additional items to be included in the glossary, as we work our way through the 6 weeks of the MOOC. So please only suggest additions there, not as a separate thread. Best regards Bert Tue 6 May 2014 4:00 AM PD

Welcome to week 2! Dear MOOC Participants Welcome to week 2! Week 2 deals with wind-tunnel testing. It consists of 7 modules with one quiz at the end. The modules and the quiz are now available. In the course of week 2, also: - the extra module for week 1 will be prepared and uploaded - all information about the peer-graded assignment will be uploaded - the date for the physical meet-up in Eindhoven will be announced Best regards Bert Sun 4 May 2014 3:00 PM PDT

New research result: Bahrain WTC is the wrong way around. Dear participants This MOOC contains some brand new research results, which is one of the reasons why it took us quite long to get it ready. These results will be presented in the coming weeks, but some main conclusions are already communicated to you via the announcements and emails from the Coursera website. For the first of these new research results, please see this link: Bahrain WTC wrong way around.

The Bahrain World Trade Center is without doubt an excellent design. A lot of attention has been devoted to shaping the two towers in such a way that they do not only amplify the wind speed in the passage between the two towers but also align it to be parallel to the wind turbine axes. However, the design would have been ever better if the whole building design (two towers and turbines) would have been turned 180° around.This would have provided 14% more wind energy on a yearly basis. Turning the towers and turbines 180° around to get more energy appears very illogical and counter-intuitive, but a series of dedicated wind-tunnel measurements and Computational Fluid Dynamics (CFD) simulations on a model of the Bahrain WTC all confirm this result. The reason for this coincides with the first question asked in the introductory module of our MOOC, about which V-shaped building configuration yields the highest wind speed in the passage. This is always the diverging arrangement, not the converging arrangement (see figure and references to scientific papers below). Why and how this happens will be

explained in detail in in Week 4, Modules 9 and 10. Note: we performed simulations both generic building configurations in 3D (see figure 1 below) and the actual configuration of the Bahrain WTC (see figure 2 below). Best regards Bert REFERENCES: (to view, open link in new tab) Blocken B, Moonen P, Stathopoulos T, Carmeliet J. 2008. A numerical study on the existence of the Venturi-effect in passages between perpendicular buildings. Journal of Engineering Mechanics - ASCE 134(12): 1021-1028. (preprint:

)

Blocken B, Stathopoulos T, Carmeliet J. 2008. Wind environmental conditions in passages between two long narrow perpendicular buildings. Journal of Aerospace Engineering - ASCE. 21(4): 280-287. (preprint:

FIGURE 1:

FIGURE 2:

)

Sun 27 Apr 2014 3:00 PM PDT

Welcome & short movie on aerodynamic suit Dear MOOC participants Thank you for registering and for joining this MOOC on Sports & Building Aerodynamics! After 8 long months of preparations, we are almost ready to go. Later today, the introductory module and all modules of Week 1 will be published on the Coursera platform, at which time you can start watching them and doing the quizzes. Please start by watching the introductory module, as it contains quite some important information on this MOOC. As an illustration of what you can learn in this MOOC, see this short You Tube movie on an aerodynamic running speed-suit: https://www.youtube.com/watch?v=hQZVWjuroiM How and why this suit works as a speed-suit, will be explained in detail in Week 1 of the MOOC. Week 1 contains quite some theory and it might be experienced as a rather tough week. Nevertheless, we have tried to make it as attractive as possible by providing many examples and explaining the relevance of the theory for cycling aerodynamics. The motto for Week 1 is derived from Aristotle: "the roots of education are bitter, but the fruit is sweet". If you have friends or family that are also interested in this MOOC, please tell them they can still register. They can still join the Signature Track up to 2 weeks after the start of the MOOC. We look forward to working with you in this MOOC!

Thank you Best regards Bert Sun 27 Apr 2014 12:59 AM PDT

Short Introduction Movie now available - with Highlights, Quiz Questions and Course Contents Dear Participants Thank you very much for subscribing to the MOOC on Sports & Building Aerodynamics. Our Short Introduction Movie has now been released. Please have a look at this site or at: http://www.youtube.com/watch?v=TbaKkVY43Dg It took us quite a while to get this finished but we hope you will like it. I look forward to working with you in this MOOC. Best wishes Bert Blocken Mon 20 Jan 2014 11:30 AM PST