Dynamic behavior of the oil film for elastic ring squeeze film damper using perturbation method

Purpose The elastic ring squeeze film damper (ERSFD) is a key element of the high-speed rotor system in aero-engine. By far, the dynamic characteristics of ERSFD has not been investigated throughout. The purpose of this study is to investigate the dynamic behaviors of the ERSFD oil films considering the fluid inertia effect with using the perturbation method. Design/methodology/approach The perturbation equations for the ERSFD, including the journal’s acceleration perturbations, are derived by using the Taylor series expansion, and a comparative study of the oil film dynamic behaviors between the perturbation method and the parameter identification method is conducted. Findings The dynamic coefficients of ERSFD exhibit periodic change during an entire circle of whirling; the dynamic coefficient of the inner oil film is an order of magnitude larger than that of the outer oil film; the cross-coupled coefficients of the ERSFD’s oil film cannot be disregarded; the fluid inertia effect can increase the direct stiffness and damping coefficients. Originality/value The perturbation method can be used to calculate the complete dynamic characteristics of the ERSFD with the attitude angle, including the direct and cross-coupled dynamic coefficients. This work contributes to existing knowledge of ERSFD by providing a detailed analysis of dynamic coefficients.