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Old 05-31-2013, 11:12 AM   #36 (permalink)
kach22i
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Quote:
Originally Posted by Sven7 View Post
This is why we always recommend putting large radii on boat tails.
I've done some research into hovercraft ducts where we go from round to square/rectangular in a convergent taper. Building a boattail would be similar in that we would be going from square to round with a convergent taper.

Other than a generalized arc from the template which must be twisted in 3D to even be considered relevant, I see no direct application of the template in long section if the cross section is a total bust.

This is a classic case of trying to fit a square peg into a round hole (half round hole actually), maybe there should be vetting process to avoid such situations in the future.

Quote:
Originally Posted by freebeard View Post
I've taken the same journey as you—that's what prompted the 'Does it have to be a half-body...' thread. I was asking how much violence you can do to the template and still have it respect you. Nobody addressed it as I had hoped.
Sorry, I have failed you (and myself), other forums dedicated to aerodynamics must be reading this and having a good laugh on us all. Like I said I feel embarrassed, and now embarrassed for anyone suckered into this great folly.

I like the aero-template as a concept which I can keep in the back of my mind, but as the tool it was intended to be, it's fallen short, way short in my opinion.

Perhaps a better tool would be a box in section proportioned to a typical road car's length and a typical windshield, then given a "known to work" boattail.

Such a template would be applicable to retrofitting existing cars/trucks, but the gold standard Part-C template could be reserved for scratch built projects with a hemispherical cross section.

Just my thoughts.
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Last edited by kach22i; 05-31-2013 at 11:41 AM..
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