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Old 03-10-2013, 04:28 AM   #107 (permalink)
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Originally Posted by Shortie771 View Post
Well this is a $15,000 program, luckily it's free for about another week... Other than that you lost me in the fourth paragraph. I know these models that I am using and editing are far from perfect, but I thought it would be it at least a bit closer.
Autodesk makes some amazing software that I will never ever be able to afford on my own. Unfortunately, like aerohead said, it may not be good enough in this case. Drag is extremely difficult to calculate for any but the simplest shapes, and often even very good numerical approximations are way off. There might be some parameters you can play with in that program that will yield some more reasonable results.

That being said, you may have started your kammback too low. I'm no aerodynamics expert (I just do the coding), but my understanding is the curve of the template at the 0 mark is supposed to lie tangent to the roof of the vehicle. When you did it in Paint, it looked right, but you have the template set too far forward in the later image. This is consistent with the results from the program, which appears to be telling you the kammback is dropping off too steeply. The program may be a lost cause, but I'd be interested to see what it tells you if you align it to the 0 mark.

Update regarding the IE bug: I haven't gotten around to really looking at it much. I have identified one problem, though there may be more, but I haven't really begun looking for a solution yet. I haven't forgotten you and other IE users, I just have a lot on my plate at the moment.
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KamperBob (03-10-2013), Shortie771 (03-10-2013)