DENIS SMITH wrote:

>From your HP formula if my memory of Algebra is
correct Thrust should equal HP times 300 divided by
SPD.  Am I missing something here?

Depends on the units used for speed (SPD). MPH, Kts, Feet Per Second or
Furlongs Per Fortnight?

In the english system one HP is equal to 550 pounds (drag or thrust) moving 
at one foot per second or 33,000 pounds moving at one foot per minute. 

I think it was James Watt that came up with this back a couple of hundred 
years ago. In some systems HP is given in Kilo Watts. One HP is 746 watts or 
0.746 KW which is a handy way of expressing it under certain circumstances.

For prop efficiency and aircraft performance 550 pounds moving at one foot per
second is better IMHO.

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org