Scott;
I think the airflow required to flow through an internal duct to relieve
that low -pressure area behind a car would be enormous. Shaping the
bodywork to allow the external airflow over the body to smoothly merge
into the area behind the car is what will keep that area from creating a
very low pressure. Doing that without creating parasitic drag is the
difficult trick.
Take a look at Jim Hall's last Chaparral-- the intent of those blowers
was to create a low- pressure area under the car for downforce but their
exhausts were into the rear low- pressure area behind the car-- a
"twofer."
Regards, Neil Tucson, AZ
-----Original Message-----
From: owner-land-speed@autox.team.net
[mailto:owner-land-speed@autox.team.net] On Behalf Of Scott Cowle
Sent: Wednesday, November 09, 2005 8:23 AM
To: land-speed@autox.team.net
Subject: drag behind a car
I have been trying to learn more about the effects of the low pressure
area behind a car that is left there when a car moves through the air,
and trying to imagine ways to efficiently fill this area so it doesn't
act as a drag or destabilizing effect on the car. Can anyone shed light
on the subject as to how different efforts have tried to eliminate this
low pressure. Is it safe to assume that was the logic behind the boat
tail cars. Also, what would be the effects if one were to run some kind
of tubing from the headlight area back to the tail light area so the air
is effectively passing through the car and exiting in this low pressure
area. I watched a take off of an "Intruder" I think it was an intruder
and I noticed the air intakes protruding from the side of the aircraft.
Could something like this be used to redirect air through the trunk of
the car to the back of the car without creating as much drag as at the
back of the car. We are toying with the idea of building a!
Dodge Shadow with a 340 small block , where the engine will be moved
back, as will the driver-in sort of a funny car type position, but I
want to make this a stable car- so its going to be low and have an aero
package of some type but I don't know what yet.Its November and now is
the time to play with ideas for next time I get down to where the fun
is.
Scott
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