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Old 10-13-2010, 06:04 PM   #4 (permalink)
aerohead
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equation

Quote:
Originally Posted by Patrick View Post
I don't know where this equation came from, but the H+W+H x L portion seems to be calculating the surface area of the car. If so, shouldn't there be another W for the bottom of the car? Or is that just ignored for the equation?
Patrick, this equation is from Daugherty's Fluid Mechanics text.
The 'mirror image' surface below ground is ignored.
The 'bottom' surface of the vehicle is ignored ( it will be a component of the pressure drag ).
Only the above the belly perimeter ( sides and top ) along with length are used in the surface area.
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