COMPLEX RESPONSE OF A HIGH-PARAMETER TURBO ROTOR MODEL UNDER THREE NONLINEAR FORCES

The dynamic equations of a flexible symmetrical rotor of a single span under three nonlinear forces, the oil film force, the airflow force and the seal force are established. Considering the parameters of high speed, large airflow velocity and a small seal clearance, the dynamic behavior of the system is studied with a numerical integration method by the software of Matlab. The results show that: with the change of rotary speed, the system shows a complex dynamic behavior containing periodic movements and quasi-periodic movements. With the change of airflow velocity, the instability of the system will occur suddenly, and windows of period-6 and period-3 movements occur after that; the amplitude of period-3 movement increases suddenly and the window becomes high. With a small seal clearance, the system has quasi-periodic movements, in which the period-1 movement is contained.