Be aware that HVAC ducting is generally not dealing
with air flows that they have to slow down from 160 + MPH. While I do
not pretend to be HVAC knowledgeable - the environment and conditions are
different - that is not to say there may not be good ideas there - just a
different environment.
<snip>
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
I agree, Lynn most rules do not change.
However, making air turn at different velocities can be a factor that is
affected. A curve that will turn air with minimum turbulence at 10 mph
velocity may create severe turbulence at higher velocities. From what I
read, the Reynolds number plays a key role in boundary layer interaction on
surfaces even when not supersonic. On the other hand, since 99 % of what
we do is at the eye-ball engineering style - any examples is bound to be
helpful.
Ed