Dynamic analysis of an elastic ring squeeze film damper supported rotor using a semi-analytic method

Abstract

To speed up the calculation of dynamic analysis for elastic ring squeeze film dampers (ERSFDs) and investigate the dynamic characteristics of ERSFD-rotor systems, a semi-analytic method (SAM) is proposed for analyzing oil film pressure and force. This method is subsequently verified by comparison with numerical simulation and experimental results. Based on this SAM, an improved dynamic model of an ERSFD-supported rotor is developed by coupling the kinetic equations of the rotor with the determination of elastic deformation. Using this method, the oil coefficients and vibration behaviors of the rotor such as the amplitude-frequency relation and the influence of sudden excitation are investigated. The results reveal that the equivalent oil coefficients and damping ratio of the system can be increased significantly by the adoption of ERSFDs. Therefore, the nonlinear bistable response occasionally occurring in traditional squeeze film damper (SFD) supported rotors is effectively suppressed and the transient vibration process caused by sudden unbalanced excitation action is significantly shortened. The SAM enables one to reduce the computation time of the previous method by more than 90%. Such a reduction greatly improves the computational efficiency.

Dynamic analysis of the rotor system with elastic ring squeeze film damper considering oil film temperature

“…1b. Based on the π-film assumption and rigid boundaries, the ERSFD's theoretical equations can be expressed as [2,17]:…”

“…In order to investigate the ERSFD rotor's characteristics, Zhang et al [3] adopted the FDM to analyze the reaction force of ERSFD rotor and investigate the parametric behaviors of ERSFD. Han et al [2,17] adopted the semi-analytic method to solve the reaction force, and the ERSFD rotor's behaviors under the sudden unbalanced excitation were analyzed. Considering the contact deformation of elastic ring, Wang et al [18,19] proposed the fluid-structure interaction method to solve the reaction force and pressure distribution of ERSFD.…”

Research on Sudden Unbalance Response of Rigid-Elastic-Oil Coupled Ball Bearings

“…Scholars have investigated the dynamic characteristics of ERSFDbearing-rotor systems under sudden unbalance. Han et al [39] studied the dynamic response of an ERSFD-rotor system, and the installed ERSFD could effectively suppress the nonlinear bistable response of the SFD-supported rotor, significantly reduce the transient amplitude caused by sudden excitation, shorten the resulting transient vibration process, and avoid the "soft" jump response of the rotor. Zhou et al [40,41] fully considered the coupling effect between the rotor and a floating ring squeeze oil film damper (FSFD) [42] and studied the inhibition effect of the FSFD on the sudden unbalanced response of the rotor system.…”

“…The ERSFD could effectively suppress the transient response caused by the sudden unbalance and significantly reduce the additional vibration caused by sudden unbalance. However, regardless of whether the elastic ring is fixed [39] or not [40][41][42], there will be a coupled bearing excitation, and the dynamic characteristics of the rotor are analyzed. Yang et al [44] established an integrated dynamic model of ERSFD-ball bearing considering the bearing excitation and analyzed the effects of bearing speed and squirrel cage stiffness on the dynamic response of the journal.…”

Dynamic analysis of the variable stiffness support rotor system with elastic rings

“…Chen et al [24] established the spiral bevel gear drive model with ERSFD and studied the dynamic characteristics of this system. Han et al [25,26] proposed a semi-analytic method to analyze the oil film force of ERSFD and established a Jeffcott rotor model with ERSFD. Subsequently, this model was solved by Runge-Kutta method and the dynamic response of the ERSFD-rotor was analyzed.…”