X-Mozilla-Keys:                                                                                 
Al Gietzen wrote:

Paul;

effective cooling.  His results bear that out.  He is cooling a 200 hp
engine effectively with a radiator area of only 126 sq. in.; better than
our theory says is possible.

Perhaps it is not 200 HP Al :-) PL

Quite possibly.  126 in^2 may be effective at cruise; but he hasn't said
whether he can make an extended climb on a 100 degree day.

You have a point there but don't forget Tim England's increased frontal
area and drag coef. for that increased frontal area. The duct could
be narrower or a NACA duct used to feed an internal rad on pushers. PL

True, having the external diffuser has a drag penalty, but mostly due to
surface area.  If the shape gives him good pressure recovery inside, one
would presume it also has low drag outside; and I am presuming.

One reason it is working well for him is that the scoop is out far enough
from the surface to be in the free stream velocity.  That far back on the
fuselage the boundary layer is 2"+; so a scoop at the surface, or a
submerged inlet (NACA) would have to have considerably larger opening.

Al Gietzen

Klaus LSE is cooling a 150 HP O-200 with a NACA duct. He also has the
fastest Variez in the country at about 250 MPH.

Paul Lamar


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