A novel study on the hydrodynamic performances of squeeze-film-damper with radial misalignment effect

The stability of lubrication characteristics of squeeze film damper (SFD) under non-circular whirl trajectories, static eccentricity, and misalignment is unclear. To address this problem, a fluid domain model of the SFD was developed that incorporates non‑circular whirl trajectories, static eccentricity, and misalignment angle. The influence of operating conditions on the lubrication characteristics was analyzed, while the underlying mechanisms were revealed. The results show that aforementioned conditions adversely affect the stability of the SFDs. Specifically, an increase in the non-circular whirl trajectory parameter reduces the static characteristic values and enlarges their fluctuation amplitudes, while leading to a higher average damping but a lower average stiffness. In contrast, larger static eccentricity and misalignment angle result in an increase in the static characteristic values, their fluctuation amplitudes, as well as both average damping and average stiffness. Additionally, when the oil film width is small, raising the oil supply pressure or viscosity can improve the dynamic characteristics. The findings provide a theoretical basis for evaluating the lubrication characteristics of SFDs under special operating conditions.