Vance W Jaqua wrote:

If you would use a very clean airframe wih a small nose, your cruise

and top

speed
would not be too bad. The take off and slow clmb would be the pits.

At

small
disc diameters and slow speed [more] blades will not make

up for small diameter.

Vance

Vance, Have you ever done a study on using a near full diameter prop
that is spun faster by an engine like the rotary with a good high RPM
potential? I was thinking of something like the UDF studies that were
done for jets. If I recall they were even looking at a supersonic
transition blade. I thought this might make a fixed pitch prop possible
for a wider operating range. Possible? Or was I taking too much cough

syrup?

bill Jepson

Bill - and others, There is some data that suggest that transonic, and even
sonic blade tips are not as lossy as generally assumed. My propeller
program is not sophisticated enough  to evaluate the level of these
losses, and the noise level problems are pretty real. The F1 air racers
are turning 4300 with pretty good results, and the tip speeds on the
Russian "Bear" are reputed to be about Mach 1.1 tho the noise
level is also reputed to be physiologically damaging. = Vance

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.