Quote:
Originally Posted by JSH
If I understand correctly the stock rear trim is 17 degrees. Your structure is 14 degrees, and you have a taped panels to connect the two angles.
There is no effect because the flow is separating before it reaches your added structure. The stock 17 degree angle is too much.
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Interesting observation, and seems to match what has been posted in the forum previously.
2009
Maximum angle for boat tail?
https://ecomodder.com/forum/showthre...tail-8927.html
Quote:
Originally Posted by Bicycle Bob
Speed affects the Reynold's number, which has a small effect over the range we are concerned with. The classic answer to afterbody taper is 15 deg. top and sides, and 4 on the bottom. Those are average best numbers, but can be affected by many other factors.
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I know first hand how frustrating things can be when trying new things.
Hang in there JohnForde.
Is there any way to change materials to something clear like acrylic so that it is continuous along the sides?
I'm just thinking that something less than half the extension you have now with similar angles three sides and full length at the sides will be more effective.
2005
New Boat Tail Design Could Improve Class 8 Truck Fuel Economy by 10%
https://www.greencarcongress.com/200...at_tail_d.html
Quote:
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The Clarkson researchers evaluated more than 100 different design geometries, where cavity length, boat tail angle, and inset from the trailer edge were varied at yaw angles up to 9 degrees. They found that the optimum geometry of a four-foot device with a boat tail angle of 10° and no inset could reduce the indicated drag coefficient up to CD=0.12.
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