供气压降下气体轴承-转子系统瞬态特性流固耦合分析

Analysis of Transient Characteristics of Gas Bearing-Rotor System under Fluid-structure Interaction and Supply Pressure Reduction

为研究供气压力波动对气体轴承-转子系统瞬态特性的影响,采用一种流固耦合仿真与实验相结合的方法,对空载及加载下气体轴承-转子系统在不同转速和供气压力下降时的转子下端偏移、轴心轨迹等变化规律进行了研究。结果表明:供气压力以斜坡形式下降时转子下端偏移理想轨迹的距离呈现波浪式变化,且工频条件下的轴心轨迹重复性变差;加载时供气压降前后转子下端偏移差值明显高于空载状态;供气压降前后转子下端偏移差值随着加载力和转速的增大而增大。

To research the influence of supply pressure fluctuation on the transient characteristics of gas bearing-rotor system,it is taken that the numerical simulation of fluid-structure interaction combine with experiment validation to study the rule of the rotor lower end offset and axis trajectory under no-load and loading conditions with different rotational speeds and the supply pressure reduction.The results show that supply pressure reduction on a slope causes the phenomenon that the distance that rotor lower end deviates from the ideal trajectory varies in a wavy manner,and the axis track repeatability of power frequency becomes worse.Before and after the supply pressure reduction,the offset difference increases with the increment of loading force or speed and during loading,it is significantly higher than that of the no-load state.