Quote:
Originally Posted by aerohead
1) As to EBLA on prismatic bodies, the 'optimum' angle for drag reduction is a function of the aft-body length, compared to the overall length of the vehicle, represented as a percentage. Hucho gets into this on page 153. For a vehicle with the lo/l= 0.45,the lowest drag is achieved at 22-degrees downslope angle. So it's very conditional.( from Buchheim et al.)
2) For EBLA on 'curved-roof' vehicles, on page 154, Buchheim et al., found that for a vehicle of lo/l= 0.336, the optimum angle for low drag was 22-degrees.
3) For the Audi 100-III, the drag minimum was found at a backlight-to-boot angle of 17-degrees. (page 156,157)
4) Wunibald Kamm recommended that one never exceed 10-degrees. That would never pass muster.
[snipped - massive amount of theory]
|
Thanks, but I'll go based on what I can directly measure on the road (attached/separated flow, lift/downforce, surface pressures) and what professional aerodynamacists have told me.
The days of trying to make up rules that are then extrapolated to all cars are long gone. We can now just measure what is actually happening on our own cars, each with their unique shape. And measure that in real atmospheric conditions, on real roads - and all at low cost.
Seeing what is
really happening - not what 'Aerohead' theorises will happen.