FR-S Initial CFD Case

We have done some CFD work for the FR-S to get a baseline result.  The model does have a flat floor, so the coefficients are not 100% representative to the real car since the underside of most vehicles resembles rough surfaces.  However, we have attempted to account for this as best as we can by adding a boundary layer condition to the underside which simulates a rough surface.  This effect, however, can be theoretically determined to have a maximum total decrease of the drag coefficient of 0.045 according to R. Buchheim [1].

The results show the coefficient of drag is 0.262, close the OEM rating of 0.29.  Using the theoretical data from the smoothed underside, the coefficient of drag we calculated is valid. The coefficient of lift is .179, meaning the car does generate lift in its stock form.

[1]  Buchhiem, R., Leie, B., Luckoff, H-J., “Der neue Audi-100-Ein Beispiel fur konsequente aerodynamishce Personenwagen-Entwicklung,” ATZ, Vol. 85, 1983, pp419-425.