[aerohead]

Originally Posted by Patrick

GM (Aerovironment) claims that they were able to achieve laminar flow with their Sunraycer:

"In the GM wind tunnel, we were able to put a stethoscope against the body and hear whether the flow was laminar or turbulent. If it was laminar, the sound was smooth, a whooshing; turbulence burbled. We were able to confirm that the flow over the front third of the car was laminar everywhere except for two thin wedges just above the side edges starting back about the middle of the front wheels. It was not clear why the flow was not laminar there, but as it represented less than one percent of the drag of the vehicle, we were not overly concerned."

Bart Hibbs, Lecture 2-2: Sunraycer Aerodynamic Development, p 28, in GM Sunraycer Case History, 1990.

PS: Speed was 40 mph.

Patrick,did Bart say that the boundary layer was laminar,or the flow outside the boundary layer?