[Land-speed] [BULK]Re: Polar Moment

[Ed Weldon]

I mentioned polar moment mainly because deliberately moving the engine back
like they do to improve handling in road cars is really counterproductive in
most cases in our LSR cars.  But how much?   We're a long way from knowing
enough about the spin dynamics of an LSR vehicle to be able to put any
numbers on the various influencing factors. (that would be a NASA project)
Heck, we don't even have any real data on the aerodynamics of a car as the
front to rear axis of symetry on which the center of pressure (CP) sits
moves angularly (yaws) with respect to the direction in which it's
traveling.  (This would be an interesting wind tunnel experiment which I
suspect has been investigated for aircraft).

We only have the most general idea of where the CP is and especially how
fast it moves as the yaw angle increases.  Sure, on an arrow it goes right
back near the tail feathers and stays there as the angle increases.   But
howabout on Kieth's Camaro or an '86 Toyota Corolla or a  roadster with a
big flat grill shell.  I wonder how small you could go with scale models and
still get useful info.  Can any of you guys who really know something useful
about wind tunnel testing (I don't) comment on this scaling thing?

I wonder if some of the scale model body shapes available like to the RC
model builders are big enough to test in a small wind tunnel.  I even wonder
if this could be a sophisticated "garage project?  Anyone have some
engineering school contacts?  This could be a neat senior or graduate level
project for a mechanical engineering student or a group.

Ed Weldon .....uhhhh........off on the edge again.