View Single Post
Old 12-18-2020, 02:59 PM   #54 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,335
Thanks: 24,453
Thanked 7,394 Times in 4,789 Posts
How

Quote:
Originally Posted by AeroMcAeroFace View Post
"How did you calculate those figures without a complete pressure map of the cars in question? You know as well as anyone here that drag force on a three-dimensional body cannot be calculated from a few centerline pressures, and Julian has never claimed such."

this was the question asked by Vman455, I don't think that has been answered. We know how you calculated the pressures at different speeds, but if you only have measurements along a centreline, how do you somehow get total drag?

From a 2D plot, somehow you have created a 3D plot, the insight is not a body of revolution.
Didn't have to. I was only relating the original values, from the original locations measured, at the original, lower velocity, to a new, higher reference value, consistent with other pressure profile reporting in the literature. Which allows comparison at equal velocities, something lacking in the original presentation. Apples to apples!
The car's contour doesn't change, nor it's influence.
The obvious discrepancy between delta-P, from forwards, to rearwards stagnation points, and the implication, as to drag coefficient is interesting to me, being 180-degrees out of phase with convention.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote