How Do We Replace Wind Tunnels With Computational Fluid Dynamics (CFD)

Duncan Phillips
RWDI, Guelph

The use of computational fluid dynamics (CFD) is becoming an increasingly popular means to model flows in and around buildings. The first published application of CFD to indoor building airflows was in the 1970's. Since then, CFD usage has expanded to include different components within buildings and flows outside.

Wind tunnel testing of buildings for wind loads has existed for approximate a decade longer where it was pioneered during the design of the World Trade Center Towers in New York. Since then, the understanding of the planetary boundary layer, instrumentation, methodologies and analysis have been continuously refined.

There is a drive to replace wind tunnel testing with computational methods. The thought being that CFD is quicker, less expensive and places control with the architects. While these are admirable objectives, the design community is being fooled into believing that CFD is completely ready. Unfortunately, there is little information available to building owners and architects on the limitations of CFD for flows around buildings and communities. Firms that propose using CFD are unchallenged by facts on its limitations. Hence building owners, developers and architects are not aware of the risks they incur by using CFD for different studies traditionally conducted using wind tunnels.

THE PURPOSE OF THIS SEMINAR is to explain what needs to happen for CFD to replace wind tunnels. The three main challenges will be discussed, along with ongoing research and how they impact the results. Attendees will leave the session with a better grasp of how CFD works and questions to ask when acquiring either CFD or wind tunnel services to maximize value.