速度滑移对液静压轴承油膜微流动影响敏感度

为了使液体静压轴承油膜性能的研究更加准确,基于计算流体力学(computational fluid dynamics,CFD)和有限差分方法,研究了液体静压轴承间隙油膜微流动的速度滑移现象及其对轴承性能的影响,并定义敏感度物理量对影响程度进行评估.在传统油膜流动假设条件基础上,引入Navier速度滑移边界条件对传统的Reynolds方程进行修正,通过有限元差分方法求解修正后的Reynolds方程,采用梯形积分公式求解轴承承载力等性能参数,对速度滑移影响的轴承性能的敏感度做出定量和定性分析.研究结果表明:油膜压力分布、轴承的承载力、动刚度及油腔流量等轴承性能对速度滑移都有一定的敏感性.最大油腔压力随滑移系数的增加而减小;速度滑移在一定程度上提高了轴承承载能力和油腔流量,但同时降低了轴承动刚度,流量对速度滑移的敏感度最大达到100%.

Sensitivity of the Impact of Velocity Slip on Hydrostatic Bearing Oil Film Micro-flow

To accurately research the hydrostatic bearing oil film performance,based on the computational fluid dynamics ( CFD) and finite difference method, velocity slip phenomenon of the oil film micro-flow in hydrostatic bearing clearance and its influence on bearing performance are investigated. The sensitivity parameters are defined to evaluate the impact of velocity slip on the bearing performance. Based on the conventional assumptions of the oil film flow, the conventional Reynolds equation is modified by introducing Navier-slip boundary condition. Modified Reynolds equation is solved by finite difference method, and the performance parameters such as bearing capacity are deduced using the method of trapezoidal integral formula. The parameters of sensitivity are used to make a quantitative and qualitative analysis. Results show that bearing performances such as the distribution of oil film pressure, bearing capacity, dynamic stiffness and oil cavity flow have a certain sensitivity for velocity slip. The maximum cavity pressure decreases with the increase of slip length, to a certain extent, the load capacity and oil flow of the bearing are improved;however, the dynamic stiffness of the hydrostatic bearing is reduced at the same time. The maximum sensitivity of quality flow to velocity slip is 100%.