View Single Post
Old 11-18-2020, 01:47 PM   #83 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,272
Thanks: 24,394
Thanked 7,364 Times in 4,764 Posts
0.09

Quote:
Originally Posted by AeroMcAeroFace View Post
But isn't that his point entirely? That low drag can be achieved without the/a template?

It is irrelevant whether it was for styling or drag, it achieves low drag, and doesn't follow the template.

"I have understood there can be attached flow with even steeper curves, but the the lowest drag is achieved if you follow the template." where is the evidence for this claim?

The template, I am pretty sure, without wheels, theoretically has a drag coefficient of 0.09.

Many solar cars with wheels, that are real, have drag coefficients around and lower than 0.09. But also none, of the many papers I have read about solar car design, say "we used an arbitrary template as the starting point".

I don't see what is relevant about being a mechanical engineer, mechanical engineering and aerodynamics are completely different things.

(I am not saying the template is useless, but it has many claims, and I have seen contrary evidence elsewhere in scientific research papers (not just in Julian's videos))
* In free air, the streamline body of revolution that the template is derived from is Cd 0. 03769.
* The half-body derived from the streamline body of revolution is Cd 0.07538.
* The data is from Sighard Hoerner's 1951 drag table, at Reynolds number = 10-million, reproduced in Hucho's 2nd-Edition, Figure 4.119, page 200.
* There's nothing theoretical about it, since 1923.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
 
The Following User Says Thank You to aerohead For This Useful Post:
AeroMcAeroFace (11-18-2020)