STUDY ON ROTOR DYNAMIC CHARACTERISTICS STIMULATED BY AIRFLOW IN LABYRINTH SEALS

摘要

In this paper, a calculation model of the dynamic characteristic coefficient of labyrinth seal is established, the influence of rotor rotating speed and inlet and outlet pressure on the dynamic characteristic of labyrinth seal is numerically analyzed. The calculation results show that the cross stiffness and main damping are important factors affecting the stability of the seal rotor system; the increase of speed and pressure between inlet and outlet are not conducive to the stability of the system. On the basis of numerical analysis, a research device for air flow excitation test is set up to study the influence of rotor speed, pressure and other parameters on the vibration characteristics of the rotating subsystem. The experimental results show that the flow induced force increases the deformation degree of the flexible rotor, makes the stiffness of the rotor system change and changes the critical speed of the system. The flow of gas in the steam seal promotes the whirling of the rotor and makes the running track of the rotor more chaotic.