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Old 09-08-2022, 10:23 AM   #3 (permalink)
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what see

Originally Posted by freebeard View Post
I put it in "Interesting Aeordynamic..." but don't delete. It's just lost there.

What can one see from the thumbnail, that he took tuft testing to find out?
The preliminary conclusion from the tuft study infers that both the plan-taper and diffuser angle are too extreme to protect the boundary layer from premature separation, counter-flow, eddies, and turbulence.
Also, from other reportings, the addition of rear wheel skirts and a full belly pan with diffuser would have amplified the 13.7% mpg result.
So, anyone wishing to improve on the tail would select smaller angles on the sides and bottom, for the 'second-approximation' design.
When the tufts behave as up top, you're essentially 'there.'
Additionally, if the coefficient of pressure profile were to be determined, this would be 'what you're looking for', by default.
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