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Originally Posted by freebeard
Thanks, I saved it as '-->Scan12' so I can find it again. 
One would think the only caveat on the forebody would be that it not set up adverse streamlines. I need a word that means 'rotational around the axis in the direction of travel'. Or would those smooth out under the soothing effect of the afterbody?
Wasn't it Tesla that was trying to find a mathematical description of that curve? |
*It's funny about the forebody.Hucho beat up on M'o'ller for giving the original VW van so much radius up front.
*He cites F.W.Palowski of 1930,who demonstrated that once the radius was enough to maintain flow attachment,that any further rounding returns zero drag improvement.
*He applauds the Vanagon and it's 'optimised' radius,which worked out at 0.045 X body width.He shows a drag curve which he probably created himself,which clearly shows no additional improvement in drag with larger radii.
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Their does appear to be a CAVEAT back in the commercial vehicle chapter,showing the bulbous nose to have the lowest drag in crosswind.
*GM published the same findings in the early 1960s.(there's a pictorial drag table of that work at the 'full-boat-tail trailer' thread)
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There would be a mathematical formula for these profiles.A visit to the Math Dept. at the local university might fill in that blank.Volunteers?
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The streamlined bodies are a profile which is revolved around the longitudinal axis.
The noses are described as ellipsoid,and the tail is referred to as a prolate ellipsoid (NFL Regulation footballs are 'prolate-ellipsoids',Cd 0.055 average, while spinning in a perfect spiral pass)