C5

Question 1

Which components provide mass, damping and stiffness terms of rotor flapping dynamics equation respectively ?

Answer 1

Inertia, aerodynamics, centrifugal

Question 2

What is the flapping offset influence on the flapping frequency and flapping phase delay angle ?

Answer 2

Increase the flapping frequency angle and reduce the flapping phase delay angle

Question 3

Why is the flapping angle close to 90 degrees ?

Answer 3

The natural frequency of the flapping motion is close to the rotational speed and the excitation frequency is equal to the rotational speed, resonance condition

Question 4

what causes the lead-lag motion and why the rotor must have the lead-lag hinge ?

Answer 4

The lag motion is due to the Coriolis forces provided by the flap and the lead-lag hinge is used to reduce this harmonic load damage on the rotor hub