Bill,
I'm an amateur at this stuff but have read a lot and asked a million
questions to try and learn. I have a book on Automotive aerodynamics that
says a teardrop with the round end forward has a cd of approx. .05 and if
you turn that around with the point forward the cd goes up to approx. .4 due
to the trailing turbulence. It also says the teardrop shape is inherently
stable. Any Aerodynamicists out there have different info? Just because it's
in print doesn't mean it's always correct.
Howard
----- Original Message -----
From: <ardunbill@webtv.net>
To: <land-speed@autox.team.net>
Sent: Saturday, July 28, 2001 9:58 AM
Subject: Aero Effects
> Hi Folks, the discussion about aero leads me to wonder if the classic
> lakester with a body made from an aircraft drop tank isn't the best. I
> assume many dollars were spent by the plane makers to find shapes that
> are aerodynamically neutral, no lift forces in any direction, and
> minimum drag.
>
> Looks like these are still around. I suppose the tapered tail could be
> cut off appropriately for chute mounting, with no aero harm, and a
> push-bar with a roller on it out the back.
>
> I am curious about the 100 inch minimum wheelbase for an XXF lakester,
> that is a little shorter than stock '32 Ford roadster. I imagine the
> shorter the wheelbase, the less stability the car has, and if it was
> both light and powerful, the wheel-standing effect would come into play.
> All things to think about, especially at Maxton with the good traction.
>
> Jack Costella's car has a long sharp nose like an arrowhead, and the
> cross section is as small as possible to cover the driver and engine
> area. He gets tremendous results so the car "works". Perhaps the
> airplane makers preferred the teardrop form for the drop tanks, because
> it is shorter, and of comparable(?) aero efficiency
>
> I think if I wanted to build a tank lakester, I'd go for the form with
> the open rollcage and driver's head in the open. With the engine behind
> the driver there is a tradition of reduced vehicle "feel" for the driver
> so it would probably help if the driver has maximum vision.
>
> Any aero people on this list who can tell us about the theory and
> practice of belly tanks on planes??
>
> Cheers Ardun Bill
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