Friction in single actuator pitch systems
Category: Pitch Actuator
Problem
For single actuator pitch systems, is the friction defined for the whole system or for the individual blades?
Solution
When you select “Single Actuator Pitch System”, the pitch system is considered as one rotational degree of freedom.
The constant part of the friction terms (highlighted in red below) which act directly on this single degree of freedom, represent friction acting on the whole system pitch.
For the load dependent friction (highlighted in green below), the additional friction is calculated based on the loads on each blade, then summed up over the 3 blades before adding the necessary friction value to the pitch actuator DoF.
So, the green parts are “per blade”, but the red parts are “for the whole system”.
Keywords Single actuator, pitch system, friction