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Old 10-12-2019, 08:50 AM   #13 (permalink)
stcyrwm
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Join Date: Jun 2018
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Quote:
Originally Posted by freebeard View Post
Let go of the Template. It has a very narrow range of application, and is not fit for your purpose.
So if I let go of the template then I need some help from someone on how to size the boattail, which I feel more confused about at this point than when I started (not necessarily a bad thing given that I might have been on the wrong track in the first place???).

The original idea was to do something similar to the RV in the thread titled "Aero RV (custom boat tail for '95 Ford E-350 Class C motorhome)". Several people commented that the angle of the curves he used were too much which brings me back to how does one calculate how to build something where the angles are not "too aggressive"?

Quote:
Originally Posted by freebeard View Post
In 2-4ft, pace Mair, l/d (~3/6) give a 50% reduction in Cd. Of this one component.
I don't honestly know what this means other than maybe I am way over my head trying to do this, because of my own confusion reading this? I do get that a 50% reduction in Cd is good but everything before that is basically like another language, that unfortunately I probably don't have the time to learn right now.

Quote:
Originally Posted by freebeard View Post
The top and sides are straightforward, with a curve, slant or box step; the bottom needs special consideration due to the wake from the rear wheelwells.
Hmmm, "straightforward" but again if I let go of the template I have no idea where to begin other than eyeballing it based in the other thread I mentioned or going back to the original percentages I mentioned???

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