>Reference: CP CG discussion. To determine a crude center of pressure for yaw
>stability on the Mclaren I took a side photo of the car, printed and scaled
>it, put it on a drawing board and assigned the side view a series of geometric
>shapes. Then I figured the area in each shape and tried to make sure I had
>more surface area behind the known CG than in front of it. Balancing a paper
>cutout of the sideview is a heck of a lot easier and more accurate than the
>way I did it. The top and underbody fins were added to push the CP rearward
>from the original design which I imagine relied on tire traction to assist in
>keeping the car aimed at high speed. Downforce on the sloped nose pushes the
>CG and car weight balance forward the faster it goes. The car has yawed
>pretty seriously in high cross winds under 100 mph (August 2002-the hurricane)
>but on the same run it became very stable once it got up to 150 and above.
>Can someone continue the conversation with some basics on how underbody air
>under flat bottomed cars affects CP, especially in yaw? thanks
>
>
Rex
>
>.
|