Project Falcon is a free technology preview that simulates air flow around vehicles, buildings, outdoor equipment, consumer products, or other objects of your choosing in a virtual wind tunnel. Falcon technology is extremely geometry tolerant and easy to use, enabling you to begin seeing and understanding air flow behavior within seconds of starting the application. Results update almost in real-time in response to changes in wind-direction and speed that you specify. Visualization tools available within the Falcon family of applications include 2D and 3D flow lines, shaded result planes, vector plots, and surface pressure shading. Quantified outputs include velocity, pressure, drag force, and drag coefficient.
See http://labs.autodesk.com/utilities/falcon for more information.