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Old 12-23-2013, 04:55 PM   #3 (permalink)
aerohead
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8-degrees

Quote:
Originally Posted by Otto View Post
NASA Langley aero guy told me 30 years ago to keep the angle <~8 degrees to keep flow attached. That was on a body of revolution, though, but comparable concept.
*W.A.Mair's boat tail research revealed 22-degrees as the maximum aft-body contour slope which would maintain attached flow on a streamline body of revolution.
*Hucho tells us that Rolf Buchheim et al. recommended no more than 23-degrees.
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*Buchheim et al.also stipulated that for simple aft-body angles,that the angle was completely dependent upon the precentage of aft-body compared to total length of the car,for fastback cars.
*Buchheim et al. also stipulates that this slope angle will change if the the roofline and C-pillars have curvature leading into the slope.
*For notchback cars it's a whole different ball game.
*And as for 'simple' angles,the only applications for such things today would be as with the "Trailer Tail" folding boat tail,
'n maybe JEEP Wranglers,HUMMER,etc..Everything else has critical curvature and camber.
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