WIND TUNNEL TESTING ON TALL BUILDINGS WITH EMPHASES ON SHAPE

[RMG63]

Hi

I have been asked to come up with the most efficient building shape for a new multi-storey building.

I think a wind tunnel test would be best to see how the wind flows around different shapes.

Has anymone got any advice as to how I would go about designing the scale models and any general advice on wind tunnel testing?
Thanks

 

[hokie66]

This sounds like a university assignment. If so, the site is not for students. Please confirm or otherwise.

Engineers do not usually get to determine the plan shape of multi-storey buildings. And wind loading is only one factor, usually not controlling the shape, as the usable floor plate is more important economically.

 

[concretemasonry]

Much of the wind effects also depends on the near-by structures in an area that have similar structures not will have them in the forseeable future.

How many stories and does it qualify for a "high rise" where ther are more wind effects.

If you are really concerned, look at the criteria for the "old" multi-story buildings (10 to 30 stories) constructed within the last 5 years ago in Dubai, where they may be dwarfed by neighbors that may have large effects in the near future. Most of these buildings had good engineerng since the general philosophy was that good engineering was an investment since construction costs were low. - You get the best bang for your dollar in the long run.

When you design multi-story buildings you have to look at the future possibilities.

Dick

 

[cvg]

I worked in a wind tunnel lab at college. It is very common for developers to contract with the university to build the models and test them as needed. concretemasonry is correct that nearby structures can have a profound effect on your building. Wind tunnel testing typically takes this into effect by modeling nearby buildings also. See link for photo of model for the world trade center twin towers.

 

[dik]

You have to be a bit cautious in modelling. The Reynolds number is not directly scaleable and there are size issues that must be addressed. Most facilities running wind tunnel testing are aware of the issues and should be directly consulted.

Keep us posted with your findings.

Dik

 

[civilperson]

A circle needs only one analysis, most other configurations need 8 or more wind directions for complete results.

 

[cvg]

but is a circle the most efficient design?

 

[civilperson]

Area/perimeter is maximized with a circle. What is your definition of "most efficient"?

 

[cvg]

in terms of construction cost and floorplan layout, I would think a circle would be much less efficient design than say a square. However, I believe rmg63 was thinking more along the lines of efficient from a wind pressure standpoint.

 

[hokie66]

cvg,

If that is what he meant, then yes, a circle is best. There are a lot of circular buildings around, including one circular tower in Sydney called Australia Square.

 

[InDepth]

Jason Garber of RWDI (

http://www.rwdi.com)

made a great presentation at the Vancouver SEI conference in early 2008 that discussed different shapes and how to reduce drag forces through inovative building shape. Tel (519) 823-1311 Ext 2269

or call the competition:

http://www.blwtl.uwo.ca