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Old 12-03-2020, 07:57 AM   #201 (permalink)
AeroMcAeroFace
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Quote:
Originally Posted by aerohead View Post
1) boundary layer thickness has nothing to do with passenger car drag.
2) above 20-mph, a passenger car is already at supercritical Reynolds number, with 100% turbulent boundary layer. And that's a 'GOOD' thing.
But doesn't the amount of stuff ahead affect the boundary layer thickness? And doesn't that make the air less "sticky" and more likely to separate?

I would think that a longer vehicle that morphs into a semicircle compared to a shorter vehicle that morphs into a semicircle, would require different rear tapers before flow detaches.

A stretch limo has the same rear profile as the car that it is based on, but will, unless I am mistaken, have different separation characteristics.

 
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