Date:         Tue, 30 Apr 96 19:39 CDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         khooper@wsp1.wspice.com (Ken Hooper)
Subject:      Re: aerodynamics (Seriously...)


>This post is getting long.

But it was fascinating. Thanks. What I know about aerodynamics is an
agglutination of perceptions, prejudices, common knowledge and fanciful
notions that all might be completely wrong.

I think what I read about the drag cofficient of the Bus might have been in
St. John, but maybe I imagined it. I haven't looked for it because I don't
know where that book is at right now, so let's assume that the Bus is
draggier than the Beetle until I back up my assertions. But I still have a
question:

>The drag coefficient tends to go way up when air flow burbles over the
>car like eddies in a creek, rather than flowing smoothly like water under
>a water ski. on almost any car, even including out beloved bus, this smooth
>flow is easily accomplished on the front of the vehicle.

OK, but then why does Fred Porter want to put widgets on the flanks of the
bus to make it even more turbulent back there? Why does the dimpled golf
ball fly further? Was Porter's message some sort of dweebish parody that
went completely over my head (wouldn't be the first time)?

And another question:

Posit two Beetles. Both are identical mechanically, they have identical
bodies and they are driving down identical, perfectly flat roads. One
Beetle weighs a hundred pounds and the other weighs a thousand pounds.

Disregarding the friction in all internal mechanical
components--considering inertia only--once they reach a certain steady
speed, will they get identical gas mileage?

--Ken  <-substantial inertia