Russell Kent wrote:

Paul wrote:

Here is the problem I have with most prop solutions I have seen so far.

The definition of HP implies that thrust goes to infinity at zero MPH.
Prop efficiency curves imply zero efficiency at zero MPH.

Zero efficiency  times infinite thrust in this case gives a finite static thrust
number at zero MPH????

Next problem. Torque from an engine at zero MPH is finite!

What we need is a prop formula for thrust that has as its inputs; torque,
diameter, pitch, twist, solidity ratio, number of blades, airfoil number, RPM
and forward speed including zero MPH.

Did I forget anything?

Yeah, density altitude.

Russell Kent

Very good point Russel. There is plenty of evidence that high altitude props
require a higher solidity ratio.

Paul Lamar
 
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