VAWT: The virtual aerodynamic/aeroacoustic wind tunnel

Ever since computational fluid dynamics (CFD) arose as a tool for predicting fluid motions engineers have looked to the day when it could be used reliably to supplement wind tunnel tests. Limits on computer speed and algorithm accuracy have prevented the development of a virtual wind tunnel. But now, a team from Ford Research has developed the capability that allows engineers to evaluate vehicle designs both aerodynamically and aeroacoustically in a virtual environment. Starting with a CAD surface description of the vehicle, a CFD simulation can be constructed and executed with little user intervention in only a few days. This information can be used to estimate interior sound due to wind noise, which can then be played through speakers for a comparison of alternate vehicle designs. The technology that makes this possible combines a new method for CFD called PowerFlowTM (from the Exa Corporation) with an enhanced Wind Noise Modeller©. To illustrate this new capability, we will consider an analysis of the Taurus line. Aerodynamic information regarding flow around the side mirror and windshield wipers will be provided, and aeroacoustic wind-noise predictions will be made and compared to actual wind tunnel tests.

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