基于CFD的微孔空气静压轴承节流性能仿真分析

Simulation and Analysis of Throttle Performance of Microporous Aerostatic Bearing Based on CFD

摘要: 为了研究微节流孔对于空气静压轴承的节流性能的影响；本文利用CFD流体计算软件对微孔空气静压轴承的三维内部流场进行了数值模拟与计算分析；其中采用网格划分软件对轴承气膜网格进行划分，利用(Realizable K-ε)湍流计算模型分析气膜的流场特性；通过对微孔空气静压轴承的节流性能分析，研究了微孔空气静压轴承的节流孔直径对于轴承气膜内的压力及速度分布的影响，并给出了相应的对比结果；同时，将微孔空气静压轴承流场与传统节流孔空气静压轴承流场的不同区域的压力分布进行了对比，并分析了微孔节流与传统小孔节流流场之间的特点与区别。结果表明，在气膜承载面上，节流孔附近的压力降随着节流孔直径的增大，压力降呈先增大后减小的趋势；在节流孔中心线上压力随节流孔直径的增大，压力变化越不明显；微孔节流空气静压轴承与传统小孔空气静压轴承相比，在气膜承载面上，压力骤降小于传统小孔节流轴承，在节流孔中心线上，压力变化幅度大于小孔节流轴承。

Abstract: This paper is proposed to study the effect of micro-orifice on throttling performance of aerostatic bearings. In this paper, CFD computational software is used to simulate and analyze the three-dimensional internal flow field of the aerostatic thrust bearing with micro throttle holes. Meshing software is used to mesh the geometry. Realizable K-ε viscous model is used to analyze the flow field inside the film. Through throttling performance analysis of micro-porous aerostatic bearing, the influence of diameters of throttle holes on the pressure and velocity distribution inside the bearing air films is studied. The pressure distribution in different regions of the flow field of micro-hole aerostatic bearing is compared with that of traditional orifice aerostatic bearing, and the characteristics and differences between micro-hole throttling and traditional orifice throttling are analyzed. The results show that the maximum pressure drop near the outlet of the throttle holes on the bearing face increase first and then decrease as the diameter of the throttle holes increase. The pressure change along the center line of throttle holes becomes less obvious as the diameters of throttle holes increase. The pressure drop on the bearing face of aerostatic bearing with micro throttle holes is less than that of traditional aerostatic bearing. The pressure change on the centerline of the throttle holes of aerostatic bearing with micro throttle holes is larger than that of traditional aerostatic bearing.