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Old 07-14-2024, 10:28 PM   #59 (permalink)
JohnForde
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Quote:
Originally Posted by JSH View Post
A constant 19 degree angle is unlikely to keep the flow attached. GM did not design that rear trim for optimal aerodynamics.

You won't know until you test but if you are using straight panels I would shoot for 15 degrees. I would do some research on Class 8 trailer tails and see what angles they are using. No reason to reinvent the wheel.

As Aerohead said - it is a trade-off between build complexity, practically, and aerodynamic performance.
I actually think GM designed the cuff primarily for aerodynamics. But I am wondering if it is designed to allow flow separation but have some other benefit.

3" of rise over a 10" run is about 17 degrees.

Weather should be good here starting Tuesday so I may have a working, adjustable prototype late in the week and do some testing: both tuft and efficiency.
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