Quote:
Originally Posted by ChazInMT
OK, I see now where this might work on account of being long enough to allow air to reattach before falling off, and, the whole "stuff the wake" principle.
Aerostealth is only going 2 feet back which leads me to think his top panel is just going to ride along under any air tumbling off the roof when sloped to 25°. That's why I suggest a 15° angle with a curve cause if nothing else it will smoothly direct air down reducing the amount of turbulence in the wake area and shortening the turbulent area in drag behind the trailer.
I really think the length variable is significant on this application.
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My intuition is to totally agree,but I've got no prima facie evidence to back it up.And I refuse to experiment on the other guy's nickel.
Scott Funderburk,who was doing this research for his Master's Thesis did test a truncated version of GM's boat tail.
I don't have the Thesis,so,so far,the information is classified with the exception of his comment about vorticity caused by sharp edges.(something NASA never got into).
It's plausible that if the tail is truncated to 2-feet,that it will behave with a linear,or monotonic performance curve,as Hucho talks about with some mods.
Again,I don't know.And I'd never build one of these,but I'm not the boss of this project.
It is interesting that GM is using something like the 25/10/10-degree tail,with the exception of the progressive edge radii.(FKFS says this radii is good for a 16% drag reduction)
It sucks not to be a gazillionaire!
Here's a link to Scott's US Patent for a drag reducing add-on
http://pdfpiw.uspto.gov/.piw?Docid=0...iew+first+page