uploaded 10/18/99
Interesting Correction
I love the anonymous info I get!
After the Nazareth CART race I wrote a trip report (Eagle
997 Aero Details) with this photo and the following description
of a funny-looking aero doo-dad.
It took me a while to figure this out and I might still
be wrong. This is the right side of the sidepod below the engine
cover. The front opening is a scoop for engine air. The turbocharger
compressor is mounted there just inside the engine cover. Behind
that scoop this device is concave leading to another inlet. I
think this acts like a NACA duct spoiling air into an inlet for
cooling air for the elevated exhaust system. The engine inlet
scoop has some drag penalty but putting that other inlet behind
it might increase cooling flow without any additional drag. Very
clever!
Three months later I received and email message that corrected
me
You got it backwards on the Eagle "turbo tongue"
- the back opening is
the inlet to the turbo. the front opening is for shock cooling
and
serves to extract the nasty air in the corner of the bodywork.
The next message had a more elaborate explanation of the
device.
Anyway, the neat thing about the "turbo tongue"
is how it draws air into
the turbo intake even more efficiently than the scoops you normally
see.
Air from up to 2 feet away becomes "attached" to the
tongue surface
thereby forcing it into the turbo inlet actually creating positive
pressure. This works much like the underside of the wings where
most the
work is done. Any particles in the air stream cannot "make
the turn"
because their velocities are too great. This allows the inlet
particle
screen to be left off. These screens scrub about 30% off the
inlet air
velocity, so simply removing a screen makes a big difference
at least
until something is sucked into the inlet. The turbo inlet sees
about
1000 CFM of airflow!
Interesting, eh? Does anyone have a further comment?
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