Quote:
Originally Posted by drmiller100
for me, a real question is if I take an SUV, and add an 80 percent boattail to the end of it, what will my Cd be?
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I've got 8-new pictorial drag charts to post at the boat-tailed trailer thread if the scanner will work tomorrow.
Everyone should be able to deduce drag potentials from the comparative anatomy displayed.
Nearly all the numbers are directly out of the wind tunnels.I did a few extrapolations and interpolations but they should be of high confidence for prediction.
With respect to your SUV question,your results will be determined by the state of aerodynamic tuning on the base vehicle,as you will see in the railroad component data.
SUVs will react the same as any other vehicle to streamlining.
NASA took a late 70s Ford Econoline of Cd 0.48 and with softened nose,nice bellypan,and mediocre boat tail,achieved Cd 0.235.
If they had done the roof camber,longitudinal edge radii,cooling system streamlining,etc.,they would have come in at a lower number.
Gilkison's new 4RUNNER,at Cd 0.36 is nearly as clean as my CRX was new.It just has more frontal area.
With wheel covers,fender skirts,bellypan,cooling sys. mods,and tail,it can go to Cd 0.13 as well.But it would require a trailer-length tail to kill off all that frontal area.Or do part of it rigid,and the rest inflatable.I've done both.It all works.
With serious wheel streamlining as with so many of the solar cars,HPVs,and record cars,that Cd could also go lower.