[gumby79]

In order to understand automotive air dynamics one must throw out most of what know of airplane aerodynamics and only consider WIG(Wing In Ground effect) aerodynamics

This team took the NACA 4412 "best in Ground effect" and optimized it for just above road going vehicle altitudes of 20% cord ground clearance ratio. EG 100" bumper to bumper = belly pan 20" off the deck

Shape Optimization of an Airfoil in Ground Effect for
Application to WIG Craft


Yilei He,1 Qiulin Qu,2,3 and Ramesh K. Agarwal1
1 Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA
2 Institute of Fluid Mechanics, Beijing Institute of Aeronautics and Astronautics, Beijing 100191, China
3Washington University in St. Louis, St. Louis, MO 63130, USA
Correspondence should be addressed to Ramesh K. Agarwal; rka@wustl.edu
Received 31 May 2014; Accepted 19 October 2014; Published 8 December 2014
Academic Editor: Jian-han Liang


Even at 80% cord ground clearance ground effect must be considered in design
Eg 100" bumper to bumper @80" belly pan clearance is still in full ground effect and free stream aerodynamics cannot apply.



Free streem optimization of NACA 4412 versus wig optimization of the NACA 4412

PS Notice also,that nearly the entire belly of CUER is 'diffuser.' This is something Cybertruck will be able to incorporate,with it's all-wheel air-suspension.

This studdy agrees with your sediment as I understand it.
Dream big chisel down to reality