Dynamical Characteristic Analysis of Elastic Ring Squeeze Film Damper in Rotor System

Abstract

By placing an elastic ring inside the oil chamber, elastic ring squeeze film damper (ERSFD) has better performance than classic squeeze film damper (SFD) in suppressing nonlinear characteristic and good application potential in aircraft engines and gas turbines. However, it is not easy to combine the deformation analysis on the elastic ring with the oil film analysis based on Reynolds equations and dynamic analysis of the ERSFD-supported rotor accurately. In this paper, based on the Kirchhoff assumption, the finite element method (FEM) is employed to investigate the deformation of elastic ring. First, the oil film pressure and force are analyzed by solving the Reynolds equations. Then the deformation of elastic ring, oil film force and rotor motion are determined simultaneously to analyze the oil film coefficients of ERSFD and the response of rotor system. Using the proposed procedure of calculation, dynamic characteristic of the ERSFD is investigated and we found that the ERSFD is better than the SFD in preventing bi-stable vibration of rotor by lightening the nonlinearity level of the oil film. Then influences of the ERSFD parameters, number of elastic ring boss, ring thickness and oil film thickness respectively, on the oil film characteristics are discussed. The study reveals that three effects of elastic ring make better dynamical performance of ERSFD than SFD.