Prop Thrust Calcs / Bow Thrusters

[jocko_nc]

Hey all. Great forum, glad I found it.

I have been searching the net for prop thrust calcs with little success... Does anyone have basic relationship between diameter, rpm, pitch and thrust? Real-world rules of thumb? I need ballpark figures to check viability of a concept, to see if I am even close.

What I am trying to get to is the approximate performance of a bow thruster. I am looking at the suitability of a unique hydraulic motor that would, more or less, deliver 12-14 hp at 500-600 rpm direct-drive. Assuming that the market expects to see such a thruster in a 10-12 inch tube, can a single prop (10-12 inch also) convert torque to "max" thrust at that low rpm? I assume a larger diameter is unacceptable. What final drive speed do current thrusters operate? Are they gear-reduced, electric, hydraulic, both? Is 500-600 rpm a "sweet" speed for a prop? What do I need to consider?

Thanks in advance for your input.

jocko