Can anyone explain why these data show drag increasing with yaw from 0 to 15-20 degrees while every other data set I've seen shows drag decreasing? This seems suspicious.jmess said:Here is some interesting test data provided by Rolf showing wind tunnel tests done on a variety of wheels.
For the effect of yaw on drag, the one I know off-hand is zipp.com. Before anyone dismisses this as self serving, I'd point out the results have been confirmed many times by independent tests (I just can't remember the URL's).wiz525 said:do you have a link for any of the other data? I'm getting rid of my Rolfs and want to look at some of these data before I buy. Thanks.
Hell, I would love to see an X axis that actually starts at zero. Then it would be apparent that there is almost no difference in the results except for a R-Sys and Krysium SL. After, that, buy the cheapest and prettiest.wiz525 said:I would love to see an independent review.
Why would drag decrease as yaw increases?asgelle said:Can anyone explain why these data show drag increasing with yaw from 0 to 15-20 degrees while every other data set I've seen shows drag decreasing? This seems suspicious.
I could speculate, but I'm not really sure. It must involve a decrease in pressure drag overcoming an increase in skin friction, but I haven't seen anything showing exactly how the changing flow character at non-zero angle of attack results in a decrease in the total stress over the wheel surface.iliveonnitro said:Why would drag decrease as yaw increases?
This is only true of rims that have some depth to them. Supposedly, the aero shape produces an airfoil effect which provides a little relative thrust in the forward direction. For a rim like the 808 (82mm deep) the low point in the drag vs yaw curve is ~13 degrees. If you are TTing you will rarely have a greater yaw than this even on a windy day.iliveonnitro said:Why would drag decrease as yaw increases?