质量守恒边界下挤压油膜阻尼器动力特性分析

Analysis on Characteristics of Squeeze Film Damper in Pressure Boundary Conditions

气穴对油膜动力特性影响较大。研究了质量守恒边界对挤压油膜阻尼器的特性影响,基于雷诺方程和Elrod算法改进了质量守恒边界条件的统一方程,通过有限差分法求解并获取质量守恒边界条件下油膜的分布特性。研究结果表明:气穴的存在使油膜相位略有超前,当油膜负压区达到气穴压力时不再降低,而是保持为气穴压力;质量守恒边界与阻尼器的实际工作状态最为接近,它不仅提供了油膜的破裂条件,而且在油膜形成处也满足质量流量连续条件,能较好地将阻尼器在运转过程中的动力特性以及油膜承载力反映出来。研究结果对提高预测油膜特性精度具有重要意义。

As cavitation has great influence on the dynamic characteristics of oil film,the influence of mass conservation boundary on the characteristics of squeeze film damper is studied,a modified equation with mass conservation boundary condition is derived based on Reynolds equation and Elrod algorithm,and distribution characteristics of oil film under mass conservation boundary conditions is obtained by finite difference method.The results show that the existence of cavitation has an advance effect on phase of the formation of oil film.When the pressure of negative region reaches the cavitation pressure,it does not decrease,but remains as the cavitation pressure.The mass conservation boundary is closest to the actual working state of the damper,not only providing the condition of oil film fracture,but also meeting the mass flow continuous condition at the oil film formation,by which the dynamic characteristics and load capacity of operating damper are better reflected.The reserch is of great significance in improving the accuracy of predicting oil film characteristics.