Aeroguy,

I envy you. Have you ever checked out the old reports in the NASA libarary?
http://naca.larc.nasa.gov/

Some of my favorite articles are reports 684, 378, 447.

http://naca.larc.nasa.gov/reports/1940/naca-report-684/ http://naca.larc.nasa.gov/reports/1932/naca-report-378/ http://naca.larc.nasa.gov/reports/1934/naca-report-447/

To calculate the Coeff of thrust I do the following. Calculate the approx .75 percent blade angle. I take the ratio of the

Blade angle=pitch/diam*20+2 (this is approx)

You can also do the blade angle=arctan(pitch/2*pi*(.75r)
r=radius pi=3.14


Coeff of thrust= blade angle*.0025 + .05

In the example
blade angle= 4/5*20+2
blade angle=18 degrees

Coeff of thrust= 18*.0025 + .05
Coeff of thrust=.045+.05
coeff of thrust=.095
If you take .095/.0888 (.0888 is what the program use for the thrust coeff) you can change the cf in the program to 1.067.

The only other trick I use is the tip speed correction, for every 10th of mach number from Mach .4 I correct by .025 percent when the blade angle is under 17 degrees. Here the blade angle is over 17 degrees so I would stay with .095 but to show you what I mean I well do an example.

tips speed on the example would be
5/12*3.14*200=262 fps or about mach .24 (262/109)
so .24-.4=-.16
and -.16*10*.025=-.04 percent reduction

.095*.96=.0912 would be the coeff of thrust if the blade angle was less than 17 degrees

Anyway that's about everything I know on how to calculate thrust. I know compared to what your doing this is pretty simplistic but it does seem to give pretty good results.