Thread: Cd 0.38
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Old 10-26-2015, 06:21 PM   #5 (permalink)
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height/width

Quote:
Originally Posted by freebeard View Post
Cd (a dimensionless number) is what's being asserted. But I'm wondering for an equal A (area) does the height/width ratio have any impact? The Template would be .5, my car closer to 1. The Smart could be over 1.

This is based on the sides having twice the taper of the top.
Kamm and Fachsenfeld tested this at the FKFS and the short answer is no,it didn't make a difference.
They varied the width of their airfoil-shaped model from around 230mm,to 1,000mm,holding the height constant,and recorded the same Cd, on a frontal area basis.
Any car of any scale will have an identical Cd as long as Reynolds number is accounted for.They call is dynamic similarity,or verisimilitude.
The tunnel velocity must be such that a turbulent boundary layer is guaranteed.
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