07. Rotor Physics

C3 C1 L6 Rotor Physics V2

F = k_F\omega^2
M = k_M\omega^2

Measuring k_F and k_M

The values for k_F and k_M are generally found empirically. We mount the motor and propeller on a load cell and measure the force and moment for different motor speeds.

The graph below shows a simulation of the data you might get from such an experiment.

Based on the Force vs omega graph shown above, what is k_F for this propeller?

SOLUTION: 0.007

If you double the rotation speed of a rotor, how does the thrust change?

SOLUTION: Increases by factor of 4