2. Simple monorotor model

The main basic phenomena characteristic of rotor dynamics are presented using a simple but realistic example modeled by equations that are easy to solve by hand . The chosen method is Rayleigh-Ritz, and two types of rotors are studied: the first is symmetrical, the second is asymmetrical, since the behavior of symmetrical and asymmetrical rotors is different. The instability effect is then shown, and finally the influence of damping is presented. The basic phenomena are :

• natural frequencies as a function of rotation speed, Campbell diagram and instability ;

• the effect of excitation forces:...