A reduced-order model of the three-parameter fluid viscous damper with consideration of fluid compressibility and bellows volume deformation

Abstract

The three-parameter fluid viscous damper is used to isolate micro-vibration produced by control torque gyro (CMG) in satellite. In this paper, the damper is simplified by a single tube fluid viscous damper and two springs connected to the damping piston. With consideration of the principal stiffness of the bellows and the contraction and expansion effect of the damping orifice, the approximate analytical nonlinear model of the damper is established and verified by the computation fluid mechanics (CFD) method.Based on this analytical model, the displacement response of the damper and correction coefficient of hydraulic resistance are analyzed, the nonlinear characteristics in the frequency domain are also revealed.Furthermore, the energy consumptions of the nonlinear model and linear model are researched. The results show that the damper has an obvious amplitude at the first resonance peak, but not obvious at the second resonance peak. The vibration amplitude of the damping piston is only um level in the highfrequency domain. The correction coefficient of the hydraulic resistance at the resonance peak is much higher than other frequencies, which causes a significant nonlinear behavior. In addition, the energy 2 consumption of the nonlinear model is larger than that of the linear model at the resonance peak, and the larger the resonance peak, the more obvious the phenomenon is. This means that the nonlinear damping can be used to further improve the suppression of the resonance peak of the three-parameter fluid viscous damper.