Ed True enough, but most rules don't change until supersonic flow enters the picture. The turn vanes look remarkably like the vanes in the compressor section of jet engines. In all cases the losses would be lower at the lowest possible speeds. Would there be any savings in drag, if the size of the inlet openings could be changed along with the cowl flap openings? My friends Bonanza has plates that fit into the inlets for winter operation, as just closed cowl flaps are still too much cooling. Lynn E. Hanover ************************************** See what's free at http://www.aol.com. -------------------------------1180450481 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 5/29/2007 10:31:53 A.M. Eastern Daylight Time,=20 wilenius@sympatico.ca writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>

Be aware that HVAC ducting is generally not dealin= g with=20 air flows that they have to slow down from 160 + MPH. While I do not= =20 pretend to be HVAC knowledgeable - the environment and conditions are=20 different - that is not to say there may not be good ideas there - just a=20 different environment.

<snip>

True enough, but most rules don't change until supersonic flow enters t= he=20 picture.

The turn vanes look remarkably like the vanes in the compressor section= of=20 jet engines.

In all cases the losses would be lower at the lowest possible speeds.=20

Would there be any savings in drag, if the size of the inlet openings c= ould=20 be changed along with the cowl flap openings? My friends Bonanza has plates=20= that=20 fit into the inlets for winter operation, as just closed cowl flaps are stil= l=20 too much cooling.

Lynn E. Hanover

See what's free at AOL.com.

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