for quite some time I was using ABBOTT formula for static thrust estimation on a two-bladed propellers:

$$ T=6.8\times10^{-5}\times D^{3}\times p\times RPM^{2} $$

$T$ is Static Thrust (N); $D$ is propeller diameter (m), $p$ is propeller pitch (m); RPM (1/s)

I was, however, unable to find any formula which would include number of propeller blades.

Standard thrust estimation methods all seem to rely upon the "propeller disk area" which is always assumed for a two-bladed propellers.

The closes I was able to get is something called "blade solidity ratio", or "rotor solidity":

$$ \sigma = (B c)/2\pi R $$

where $B$ is number of propeller blades, $c$ is chord of each blade, $R$ is radius of the rotor.

The question is - how does blade solidity relate to thrust/power/torque?

for quite some time I was using ABBOTT formula for static thrust estimation on a two-bladed propellers:

$$ T=6.8\times10^{-5}\times D^{3}\times p\times RPM^{2} $$

$T$ is Static Thrust (N); $D$ is propeller diameter (m), $p$ is propeller pitch (m); RPM (1/s)

I was, however, unable to find any formula which would include number of propeller blades.

Standard thrust estimation methods all seem to rely upon the "propeller disk area" which is always assumed for a two-bladed propellers.

The closest I was able to get is something called "blade solidity ratio", or "rotor solidity":

$$ \sigma = (B c)/2\pi R $$

where $B$ is number of propeller blades, $c$ is chord of each blade, $R$ is radius of the rotor.

The question is - how does blade solidity relate to thrust/power/torque?