Quote:
Originally Posted by JohnForde
I might be able to install these and try them Thursday or Friday.
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I located a citation online, from a 2013 Lawrence Livermore National Laboratory piece on Semi-trailer boat tails, starting on page-12 from the top of the report.
Of special interest is 'Tail 2' a straight, 11-degree EBLA tail, top and sides, with horizontal floor.
Tail 2 produced the lowest Cd of four tails tested, @ delta-26% for a 48" , 3-sided tail, and delta-26.1%, for a 32", 4-sided tail.
If extrapolated to full-length, Tail 2 would be 263.3" in total boat-tail length, longest of the four.
The trailer's 'box' was only streamlined, starting with a wake of 80.75-sq-ft, and reducing to 67.372-sq-ft/ 62.19-sq-ft, respectively; a 16.56% / 22.97% wake reduction, respectively.
Qualitatively, a 4-sided, 48" tail would provide a delta 36.2% Cd.
It's worth a 'long' look!
https://www.energy.gov/sites/prod/fi...ari_2013_o.pdf