Bill,
If you ever get time I would love to have the specs for a fixed pitch

prop optimised for a 70" length, 225 HP and 200 to 225 MPH.  I have prop
carving on my LONG list of things to learn.

Ken Powell

Ken Powell
kenpowell@aristotle.net

Perry is building something close to that Ken for test with the LAEV
hub as we speak.

Paul Lamar

Ken,

This is approximately what the LAEV is designed for.  Since I was designing a
variable pitch prop, I haven't really looked too much at what you get when you
freeze the pitch and then run it with a variable torque vs RPM input (engine
torque curve).  This is a pretty different research path (fixed pitch prop),
altho
my software will spit out the answers for a given set of conditions, it is
not really
set up for torque right now, but HP.  It is really set up to adjust the
pitch until it
matches a specified HP at a preset RPM, alt and airspeed.

So, not undoable, just wouldl need some tweaking of the program and will need a
torque vs RPM curve for the engine at 0 MSL and 8000 MSL, the two primary
design points  (TO/climb at WOT and WOT 75% HP cruise).

PS I hope you didn't bust a gut laughing at the old composites tape.

Bill Freeman
Long EZ builder & pilot
BSME, MSME
EAA Technical Counselor

 
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