Very cool! That would have been fun. I once toured GM Powertrain Headquarters and got to see several new engines before they were released.
One little quibble...
Quote:
Originally Posted by Sven7
How fast does the air go?
The top speed of the tunnel is 155mph. As shown at the end of the video above, though, that equals out to a lot lower speed considering the model’s scale. A 1/3 scale model will only get hit with 1/3 as many air particles, so to get results consistent with full-size testing, the air has to be going 3x the speed. So, considering the size of the models being tested here, 155mph is equivalent to about 60mph for a full size car.
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I get that you are trying to simplify in layman's terms that the Reynolds number needs to be constant to compare the results on the model to that of the real car. However, it doesn't really make sense to me to state that the model gets hit with 1/3rd as many air particles. Keep in mind the frontal area of the model is 1/9th (1/3rd height x 1/3rd width) of the full size car. Scaling up the speed really has more to do with the fluid in the boundary layer acting over the length of the model. Since the characteristic length is 1/3rd as long, the speed has to be 3 times as great.