One answer if you are designing the cowl from

scratch might be to have a circular inlet (tractor) or outlet (pusher)

around the

hub and keep the rest of the cowl as far away as possible (see Mike

Arnold's

AR5).   Herb

Mike Wills wrote:

  Wouldnt this annular outlet miss the point? The idea was to place the
outlet so that the prop  would tend to draw air through the cooling system.
The annular outlet you describe puts the outlet area at the prop blade root
which may inhibit airflow rather than help. May be good for drag but from a
cooling standpoint (particularly ground cooling) I'd think you'd want the
outlets further out on the blade.

Mike Wills

Good point Mike.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org