|
wind: EPA & SAE
EPA published a chart in 1970s.
An 18-mph crosswind reduces mpg by 2%.
----------------------------------------------------------------------------
From Bain Dayman,Jr.,Jet Propulsion Lab,Cal Tech Univ.,SAE Paper 780337:
Annual mean wind spectra effect on zero-yaw Cd
Annual Mean Wind Speed,mph
5.8 10 15
Highway + 4.5% +12.0% +33.0%
This is not targeted specifically to crosswind,but will give you a feel to effect on Cd.
With respect to skirts,I've never come across any research which suggested that a skirt should be any lower than the bottom of the floorboard.
For a ground-effect racing car there would be a very carefully designed intake at front,then the rest of the car would be sealed all the way around until the very rear,where the low-pressure wake could communicate under the car, inducing downforce.
|