Quote:
Originally Posted by TimRogers
What I should have said was that that the Lockheed testing was incomplete and not reflective of real world situations. I think the coast down testing that our members do here is more relevant than static wind tunnel testing, at least for the design of the underside, fender openings and wheels.
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*FKFS had three wind tunnels. One was a rolling-road type. Fachsenfeld reports the differences in drag they measured, with and without rotation. The results would have to be considered in the context of the typical passenger cars of the day.
*General Motors also explored rolling-road wind tunnel results around 1953 and reported that the difference in data was numerically insignificant,and could be easily compensated for,through simple modifications of tires during static testing.Again,the conclusion would have to be taken within the context of the reporting timeline.
*Wolf H.Hucho basically said the same thing in 1987.For high-speed sports cars and race cars it was another matter.Especially open-wheeled race cars.
*I don't believe that there's any disagreement as to the superiority to the rolling-road technology,however,any arbitrary extrapolation regarding the magnitude in error of drag coefficients derived in earlier,static-wheel testing would be un-founded and dubious at best,unless actually backed up by re-testing of a given specific vehicle,with and without the rotation and moving floor.This is my main objection to Mr. Edgar's claims. There exists no 'a priori',generalized knowledge of drag variability as a function of wheel rotation/stasis. Any excursion from this 'condition' would demand scientific verification,on a case-specific basis.
We could attack Julian for not employing laser-doppler-anemometry when compiling his pressure study data.If the results are the same,or within some standard deviation,do we want to go there?