Let me toss this out ... from my reading and discussions with some
streamliner folks. The question the Coke bottle shape raises for me
concerns the interruption of the boundary layer around the car. The 6%
decrease toward the rear of the vehicle that allows the boundary layer
to remain attached seems to be a big factor with many wind tunnel
devotees. Breaking that flow in any area causes turbulence/drag in
that area whether it is at the front, around the wheel wells, exhaust
exits or the canopy over the driver's helmet. A narrow waist, a la
Redhead, would seem to create an interruption that counters the gains
in airflow. Turbulence off the top of a front wheel is a major factor
for lakester and roadster folks too ... the direction of the motion at
the top of the wheel is the opposite of the direction of the vehicle to
which it is attached creating air turbulence and thus drag. The air
coming off the rear of a liner isn't clean. Nish is making his vortex
generators (they gave me about a 1 mpg increase on my brick of a truck)
and really likes what they do to direct the air around the back of his
car and parachute deployment.
Obviously no conclusions, just pondering some largely unanswered
questions.
Wes
On Apr 29, 2007, at 12:15 PM, Skip Higginbotham wrote:
> Ed, don't forget that the coke bottle advantages for a car will likely
> need a top view of the car in order to balance the frontal area as the
> view proceeds from end to end.
>
> skip
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