Interesting information. Thank you.
Howard
----- Original Message -----
From: "Clay, Dale" <Dale.Clay@mdhelicopters.com>
To: "'Nafzger'" <nafzger@vtc.net>; "Glen Barrett"
<speedtimer@earthlink.net>; "John Beckett" <landspeedracer@email.msn.com>
Cc: <land-speed@autox.team.net>
Sent: Monday, January 08, 2001 8:08 AM
Subject: RE: Rear mods
> I went over and talked to our aerodynamics guy here at MD Helicopters
about
> this one. He said he could speak to aerofoils but not necessarily for
cars
> because of the ground plane effect, but ...
>
> It seems that as the car (airfoil) penetrates the air the, sharper the
> leading edge radius the sharper the pressure gradient. As the air moves
aft
> from the leading edge the pressure initially is below ambient and then as
> the it continues aft the pressure increases until it is actually above
> ambient. For a "needle nose" configuration the difference between the
lower
> pressure (still positive, but below ambient) is greater than for a more
> rounded leading edge. Because the low pressure is relatively greater, the
> center of pressure (resultant of all aero forces) would move forward with
a
> "needle nose." By the way, the point at which the pressure increases
above
> ambient may not be the same location if nothing else is change except the
> leading edge radius, so its not totally black and white as to how far it
> will move forward. (That's why we still have wind tunnels and flight
> testing, I guess.)
>
> This could still be compensated with additional areo devices aft, too.
>
> Hope that made sense ...
>
> Dale
> -----Original Message-----
> From: Nafzger [mailto:nafzger@vtc.net]
> Sent: Friday, January 05, 2001 4:45 PM
> To: Glen Barrett; John Beckett
> Cc: land-speed@autox.team.net
> Subject: Re: Rear mods
>
>
> Just another amateur opinion but in one of the many aerodynamics books I
> purchased from SAE, a comment was made that needle nosed cars tend to move
> the center of pressure forward. That was not explained, it was just a
> statement made. If that is true and you put the engine in the rear, you
are
> trying to shoot the arrow backwards with the same results as it turns out.
> Howard
>
> ----- Original Message -----
> From: "Glen Barrett" <speedtimer@earthlink.net>
> To: "John Beckett" <landspeedracer@email.msn.com>
> Cc: <land-speed@autox.team.net>
> Sent: Friday, January 05, 2001 1:04 PM
> Subject: Rear mods
>
>
> > John
> > One thing I forgot to mention on the rear engined roadster was we had a
> > long throttle throw so it was more controllable appling the power. It
> > made a big difference instead of just on and off with the pedal.
> > Glen
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