动静压耦合效应下气体轴承流场特性分析

Analysis on Flow Characteristics of Gas Bearing Flow Field with Hydrodynamic and Hydrostatic Pressure Coupling Effect

为研究静压气体轴承的动静压耦合效应机制及其对流场压力分布、承载力等特性的影响,以高速静压气体轴承为研究对象,采用CFD数值仿真方法,在不同偏心率及转速条件下对流场特性、动静压耦合效应机制、承载力以及偏心角进行分析研究。研究表明:转速和偏心率变化导致的气体黏性力、压差流和气体可压缩性变化,影响流场动静压耦合效应的强度,且造成流场的周向压力分布不对称,进而导致承载力及偏心角的变化;在相同偏心率下,承载力随转速升高而单调递增,偏心角随转速升高呈现非线性变化规律;在相同转速下,当转子保持在低速范围内时,偏心角随偏心率增大而增大,高速时则相反。

To study the effects of hydrodynamic and hydrostatic coupling effect on pressure distribution and load capaci ty of hydrostatic gas bearing,the flow field characteristic,coupling effect of hybrid gas bearing,bearing capacity,attitude angle were analyzed by Computational Fluid Dynamics (CFD) under different rotating speed and eccentricity ratio,by tak ing the high speed hydrostatic gas bearing as research objective.The results show that the change of the gas viscous force, differential pressure flow and gas compressibility caused by rotating speed and eccentricity ratio influences the strength of hydrodynamic and hydrostatic coupling effect,causes the asymmetric distribution of circumferential pressure of flow fields, and the change of force and attitude angles.At the same eccentricity rate,the bearing capacity is increased with the increas ing of the rotating speed,and the attitude angle is first increased and then decreased.At the same rotating speed,when the rotor is kept in a low speed range,the attitude angle is increased with the increasing of the eccentricity,while it is opposite at high speed.