"Jon Woellhaf" wrote in message
...
Jim Morgans wrote

OK. I have always heard the approximate rule for good cooling is double
the intake size for the exit size. Guess it doesn't transfer to
expansion.

Did you mean to write, "... double the exit size for the intake size?" If
not, you lost me.

Difficult to communicate that clearly, I guess. Try this.

If the cooling intake is 50 square inches, the exit for the cooling air is
100 square inches. For planes with moveable cowl openings, that would be
with the cowl open full.
--
Jim in NC