Presentation given at the CENAERO-BBRI event about Building Simulation tools on 2012-05-25 in Gosselies (Belgium). Introduction to Wind Engineering topics related to buildings and simulation tools.

1. Wind engineering for
tomorrow buildings
ir. Benoit PARMENTIER
Head Division Structures
www.project-simba.eu (www.bbri.be) BBRI

2. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
Into the 21th century
BBRI

3. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
Into the 21th century
BBRI

4. 1964
Wind tunnel tests of the WTC towers
BBRI

5. “
“
Wind engineering is best defined as
the rational treatment of interactions
between wind in the atmospheric
boundary layer and man and his
”
works on the surface of Earth.
- Jack Cermak, 1975
BBRI

6. Interactions : the issues
Structural Design
Comfort
Energy Production
BBRI

7. Towards contemporary Wind Engineering
Year Researcher Event
1643 Torricelli Barometer
1687 Newton Movement laws,…
…
1940 Tacoma Narrows Bridge collapse
1954 Cermak 1st ABL wind-tunnel
1954 Jensen Laws of scaling
1961 Davenport Statistical concepts related to the wind action
1963 1st International Conference on Wind action on buildings
1970 « Wind Engineering » terminology
1974 Eaton & Mayne Aylesbury House study
1984 Holmes Wind tunnel pressure tubing response characteristics
1987 Mehta Texas Tech Exp. Building
1988 Robertson & Silsoe Structures Building
Glass
1992 Murakami 1st symposium on Computational Wind Engineering
(1999) (BBRI) (Windhouse Exp. Building)* (*) humbly
BBRI

8. Burj Khalifa
163 floors
26000 glass panels A Belgian contractor was
responsible for execution
[ proud mode ]
830m
BBRI

9. Comfort @154th floor ?
Glass panels resistance against
localized pressures ?
Stability ?
BBRI

10. The reference tool : the wind-tunnel
Atmospheric Boundary Layer (ABL)
Scaled models (1:1 > 1:500)
Rotating table
Internal efforts measurements (balance,…)
Pressure coefficients
BBRI

11. Pressures integration
for horiz. displacement calculations
Location Elev. (m) Drift (cm)
Top Offices +570 125
Top Residential +375 54
BBRI

12. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
Into the 21th century
BBRI

13. Wind pressures
Turbulence effects
BBRI

14. Alan G. Davenport
The Wind Loading Chain
Dynamic Effects Uncertainty
Reference Dynamic
Pressure
qb Ce CsCd Cp µ
Pressure
Exposure Coefficient Coefficient
(roughness effects)
BBRI

15. We do not design for all situations
Whirlwinds are classified as accidental actions in Belgium
As high as 6000 Pa
# Whirlwinds en Belgique
12
10
8
6
4
2
0
1982 2010
Waregem (2005)
BBRI

16. Belgian meteorological data
Spatial distribution of the reference wind speed
qb = .ρ .v b2
1
qbb = 0,5.ρ.v b2b2
q = .ρ .v
1
2 2
10m height
Roughness cat. II
BBRI

17. Belgian meteorological data
Elevation & roughness effects
0
I
II
III
IV
q b. C e BBRI

18. The pressure coefficient Cp
The Grail Quest…
P − Pref
Cp =
.ρ .v 2
1
2
BBRI

19. The pressure coefficient Cp
The Grail Quest…
BBRI

20. The pressure coefficient Cp
Simple solutions for simple buildings…
WInt© http://www.bbri.be/antenne_norm/eurocodes TNO Cp-generator
BBRI

21. Slender
Lighter
Complex
Multi-functional
(Outsized)
BBRI

22. Research tools
Toolboxes
VKI©
Full-scale Wind-tunnel Numerical simulation
BBRI

23. Toolbox 1 – Full-scale measurements
Problem identified for semi-permeable envelopes
The Eurocode 1
assumes less
difference
BBRI

24. Toolbox 2 – Wind-tunnel
From large scale structures to low-rise buildings…
Greisch© Greisch©
VKI©
BBRI

25. Toolbox 2a – Wind-tunnel
Wind vortexes observed on roof…
BBRI

26. Toolbox 2b – 1:1 Wind tunnel
+ Rain/Snow…
CSTB, Nantes ©
BBRI

27. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
Into the 21th century
BBRI

28. Comfort : the ventilation strategy
is based on the external pressures knowledge
BBRI

29. The ventilation strategy
IAQ & Summer comfort simulations
integrate a sum of uncertainties
(local wind, local pressure coefficients, models)
N. Heijmans & P. Wouters (2002)
BBRI

30. Ventilation
Uncertainties from reference wind to local wind
Altitude [m]
??
qp [Pa]
BBRI

31. Ventilation strategy
Discomfort simulations…
DH25 is the number of hourly mean temperature above 25°C
weighted by the temperature difference (T-25)
DH25 198
173
178
138
CPe
WIND
N. Heijmans & P. Wouters (2002) – The PROBE building
Simulations with CAPSOL©
BBRI

32. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
A) Energy production
Into the 21th century
BBRI

33. Energy production – Urban wind turbines
Innovations needed to improve efficiency
Design the building to be a
“Particles accelerator” ?
BBRI

34. Energy production – Urban wind turbines
•Architectural integration ?
•Stability - Vibrations
•Production efficiency ?
•Noise ?
Les compagnons d’Eole©
BBRI

35. Energy production – Photovoltaic panels
In some cases, the wind action is underestimated
65 Collapses known in Belgium
from 01/2012
BBRI

36. The Learning Curve
The wind loading chain
Beyond structural design : A) Comfort
Beyond structural design : B) Energy production
Into the 21th century
BBRI

37. CFD tools
Tomorrow tools to determine pressure coefficients
on complex building shapes
Verrière Fondation Louis Vuitton (jardin d’acclimation Paris)
Frank Gehry©
BBRI

38. CFD tools
They need (more) validation
• Validation Full(Model)-scale-CFD
The future for Wind Engineering is also :
• Special shape  generic approach
• Automatic calculation of roughness
(GIS approach)
• More Monitoring after construction
(pressures)
Köse et al (2011)
BBRI

39. A (french) discussion forum
http://aiv.asso.fr/
BBRI

40. [Credits]
#1 VKI
#10 www.skyscraper.com
#16 RMI http://www.meteo.be
#19-20 Arthur Hugues
#22 Herzog & DeMeuron - http://tinyurl.com/3ww4cbw
Ghery & Milunic
Unfcccecosingapore - http://tinyurl.com/3maywn3
Contemporist.com - http://tinyurl.com/6beqdt
Ney & Partners – Knokke footbridge
#25 Greisch
#29 www.aucoeurdumonde.ca
#30-32 Heijmans N. & Wouters P., ”Impact of the uncertainties on wind pressures on
the prediction of thermal comfort performances”, Technical report for IEA,
Annex 35 Hybvent, BBRI, 2002
#35 www.compagnons-eole.be
#36 www.lejdd.fr
#39 Kose D.A., Fauconnier D. & Dick E. « ILES of flow over low-rise
buildings:Influence of inflow conditions on the quality of the mean pressure
distribution prediction », J. Wind Eng. Ind. Aerodyn. Vol 99 (2011)
doi:10.1016/j.jweia.2011.07.008
BBRI