-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of Ed Anderson
Sent: Wednesday, October 22, 2003 2:15 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: New cooling Model example


Hi Jim

To answer your question, I have already done that.  You can now
stick in any
gear ratio you want.  However, the only thing that it really
changes is the
prop rpm.  In other words, this simple model does not yet have a "load
factor".  I hope to be able to add that at some time in the
future, but the
problem from what little bit I know about propellers is that it would take
some math model of prop loading on the engine, thrust and airframe drag
factors. Then that would mean either everbody would have to know same for
their airframe, or some sort of simplistic model would have to be used.

 So while the model does permit your to put your gear ratio in.
I'm afraid
all it really does is calculate your prop speed for you.  Sorry
'bout that.

However, the model will calculate the rest of the stuff IF you can achieve
that rpm with your prop load (whatever that rpm may be).  You can also put
in one or three rotors (or 4 or more if you want).  I feel 90-95%
confident
that the power and BTU calcuations are within 5% (perhaps less)
of the real
world based on data I have received.  That of course assumes you have a
good induction and exhaust system.  If a bad one, then all bets are off.

If you would like a copy of the spreadsheet as it now stands let me know.

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com