Elon:
While on the subject of wheel rotation drag (it began
with open wheel cars), another poster asked about
effect on an enclosed wheel car. I can't answer for
drag but lift should be considered seriously. Pressure
created by a rotating wheel in an enclosed wheel well
(streamliners and other such vehicles) must be vented
or lift is the result. Streamliners are likely to be
effected more due to small, sealed wheel cavities and
high wheel rotation speeds. Nobody likes to cut vents
in a streamliner body but they probably should be
there none-the-less. Like Mayf pointed out, the
greatest problem area of the tire is at top. Where
would you think the vent should be?
John
--- 3liter <saltfever@comcast.net> wrote:
> I would like to simplify what I got out of the book
> review. Essentially, a
> wheel is a moving body pushing through the air like
> any other object.
> Whether it is rotating or not, as an object, it has
> a drag coefficient and
> Area. What the review is saying is that, the CdA of
> an the object
> contributes far greater to its TOTAL drag, rather
> than the fact that it is
> rotating. John Burke's comment of a few percent
> (rotational drag) seams
> quite plausible when you consider a wheel's Cd and
> trying to push a
> flat-plate area of 1 or 2 square ft at speed. Always
> enjoy Mayf's "spin" on
> things though. -Elon
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