ThrustHP's help file documents the forumulas it uses, their source, and comments on pitch.

The following (to end of this post) is cut and paste from ThrustHP's help file.
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Static Thrust Information

Formulas from AMA mag Oct 86

Load = Prop Diameter^4 * Pitch

Speed = Pitch * rpm * 0.000947

Horse Power = Load * rpm^3 / 1.4 * 10^17

Static Thrust = 0.00000000000283 * rpm^2 * Prop Diameter^4 * Air Density/29.92 * CF value


Note:

Regarding thrust to pitch variables, PRACTICAL test revealed very little if any change in thrust due to pitch variation at the same RPM. This I think is partly due to any increase in thrust being negated by blade stalling and a more turbulent influx area with increased pitch. This obviously only applies to static conditions, it's a whole new ball game under dynamic i.e. flying variables. The program is not designed to calculate thrust under dynamic conditions so it may not be of use for Ducted Fans.
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