Your patience is very much appreciated.
Quote:
Originally Posted by sregord
I found it on page 338. Figure 8.64
..and further reading: 8.5.4.5 Add-on devices on the rear end
The only drag reductions achieved(by 5%)were by the addition of non-ventilated cavities. Figure 8.65 Base-flow modification devices
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more from 8.5.4.5...The best geometry, with a cavity depth of
0.13d, reduced the drag coefficient by 5 per cent.
0.13 times 11'(tall) = 17.16"
0.13 times 8.5'(wide) = 13.26"
Quote:
Originally Posted by aerohead
It's okay to be 'open' at the rear, but not the top, sides, or bottom. The 'leakage' destroys some of the pressure recovery, the whole idea for elongation. -------------------------------------------------------------------------------------
The very last iteration of the Betterflow semi is what you want, for what's presented.
They're using the full height of the trailer (minus ground clearance ) for streamlining, and their boat-tailed cavity fits snugly against the trailer van, perfectly protecting the pressure rise.
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gluing, shaping, epoxing 2 or 3" thick pink foam to the perimeter of the rear edge, adding 13+" to the overall length of Moby ...like building a foam tail on an Insight... maybe?