基于混合均质模型的气液两相流润滑动静压轴承性能分析

Performance analysis of hybrid journal bearings in two phase flow based on liquid-vapor mixture model

依据所建立的从全液体状态经混和介质状态,直至全气体状态的连续汽化流体属性模型,联合广义雷诺方程及全能量方程,从理论上对处在连续变化低温介质条件下的径向动静压轴承的静动特性进行研究。研究结果表明,由于两相流条件下的流体压缩性发生了极大变化,因而使得处在该条件下的轴承性能不再满足全液体或全气体介质润滑下的轴承性能规律。

To meet the advanced bearings needs of cryogenic rocket engine turbopumps, a hybrid bearing was designed. An all liquid, liquid-vapor mixture and all vapor continuous vaporization bulk flow model of density and viscosity for mixture fluid was presented for prediction of bearing static and dynamic re- sponse. The general Reynolds equation and energy equation govern the two phase flow of homogeneous satu- rated mixture in thermodynamic equilibrium. The static and dynamic performances of hybrid bearing were obtained from a perturbation analysis of governing equations. The results show that the performance varia- tions of bearing operating under liquid oxygen are not bounded by all liquid and all vapor cases in the liq- uid-vapor mixture range. These behaviours are attributed to the large change in the compressibility character of the flow.