If you overly these two (175 and 150) I think you will be able to see
the effects of skin friction drag in the intake pipes. The 150 being
shorter and less draggy than the 175 while still giving good power at
6000 RPM. Namely about 235 HP. I don't want to put too much credence
in this as experimental error could be a factor. Also cruise BSFC
could be hurt if the pipes are too short. We will never know until we
get a dyno.

Paul Lamar

Hi Paul,

I learned how to do that.  These were drawn with gnuplot which I haven't
used before, but it's really quite straightforward (sort of).  I haven't
figured out how to control the colors yet, so the second plot is an
almost invisible green.  This was drawn with straight lines between the
data points.

Bob White

--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (soon)

Again I added the 2 rotor numbers on the right side.
It is very obvious here that the shorter pipe with the same diameter
indicates that internal skin friction drag is a large factor.
If internal skin friction drag were not a large factor the same HP curve
as the 150 would be merely shifted to the left.
Not only that the shorter pipe has a broader HP curve.

Paul Lamar
 
The Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2004 All world wide rights reserved.