Quote:
Originally Posted by aardvarcus
Aerohead,
I was planning on following the AST-II top profile and the AST plan taper profile (4:1 aspect ratio?) you had previously shared, unless you think there is a reason to use a different profile on this vehicle.
Thanks for sharing the VW picture, that is very helpful for designing the tire fairings. I am a bit surprised by the size of the leading faring for the rear wheels. I am also surprised by how much wider the fairings are than the wheels/tires. This may be way too complicated, but I had considered using a “U” shaped aft tire fairing with an open back and ducting some engine bay air into the aft tire fairings to “fill the wake” once the fairing ended.
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The Buchheim et al contour for roof and sides is a known quantity,so if it will save weight it would be good.
The AST-II is 1-degree more conservative with the roofline.I've not compared the plan-view.
4:1 would be safe for the sides.Some of the lowest drag vehicles have used it.
FYI: the 1981,Randal L. Peterson,NASA boattail was good for a 32% drag reduction.Torbj'o'rn Gustavsson,KTH,Department of Aeronautical and Vehicle Engineering,Royal Institute of Technology,Stockholm,Sweden,mentioned that
"A less curved (NASA) boattail would (sic) probably given larger differences between a full boat-tail with fully attached flow and a truncated boat-tail."
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The Mair tail architecture would better satisfy the attached flow condition
