航空发动机轴承腔润滑的气液两相均匀流研究

Homogeneous Flow of Two-phase Gas/Liquid Flow in Aero-engine Bearing Chamber

基于轴承腔中润滑油的两相均匀流动模型,采用湍流模式和有限差分数值方法计算轴承腔内三维定常N-S方程,对腔内润滑油的气液两相均匀流动特性进行研究,以获得气液两相均匀流条件下润滑油流场、压力场和速度场在轴承腔内的分布情况,分析转子转速、含气率和润滑油进口速度对润滑油出口压力以及润滑油与壁面之间剪切力的影响,同时对单相流和两相均匀流润滑性能差异进行比较.结果表明,转子转速、含气率和润滑油进口速度对润滑油出口压力和腔内壁面与润滑油间的平均剪切力具有不同影响,而采用2种流动模型计算出的轴承腔润滑油出口压力的差异较大,同时支持了开展航空发动机轴承腔润滑两相流动分析的必要性.

Based on the two-phase homogenous flow of lubrication oil in bearing chamber, the paper solves threedimension Navier-Stokes equations by the method of the turbulent model and Finite Differential Method （FDM）. With the research of homogenous flow performance in the bearing chamber, lubrication oil flow field, pressure field and speed field are presented. The influence of shaft rotation speeds, air volume fraction and lubrication oil inlet speed on exit pressure and shear force between walls and lubrication oil was analyzed. The difference between single-phase flow and homogeneous flow model is illustrated in details. The results indicate that shaft rotation speeds, air volume fraction and lubrication oil inlet speed affects exit pressure and shear force differently. Some differences of calculation results can be seen from two different flow models and also proves the necessity of further research on two-phase flow in aero-engine bearing chamber.