Autodesk Labs has released another Tech Preview of Vasari v2.1. It now features more Ecotect integration including wind tunnel analysis. To make a long story short, you assign wind rose data based on location of your building site to the Vasari model by selecting the data you are interested in, apply it to the model, and then in a 3d representation you see the effects of that data as the wind is pushed and pulled around your model and the site. It's a pretty amazing looking display that is sure to wow whoever looks at it. It looks like fluid dynamics swirling around your building.
Bringing sexy back with this wind tunnel animation
You can also compare various design options against eachother to figure out which massing form is best suited based on the Ecotect anaylsis data graphs after running the simulations.
Watch this short video to see it in action (highly recommended).