中介轴承集油结构内两相流动的数值研究

Numerical study of two-phase flow in oil collector of intermediate bearing

为了找到某航空发动机中介轴承集油结构集油损失的原因,采用基于VOF模型的多相流数值计算方法,对集油结构内的油-气两相流动进行模拟研究。分析了结构内的流场和滑油运动规律,并给出了内圈转速对集油效率的影响。结果表明:转速越大,集油效率越低。集油环腔内的流动以周向流动为主,在环腔子午面上出现非对称的旋转涡流。集油损失的原因是滑油从进油孔甩入环腔,与保持架内表面碰撞,分为两股油流,一股流向轴承内部,另一股流向泄漏口方向。流向泄漏口方向的滑油由于缺少流向轴承内部方向的驱动力而在油坝内侧附近积累,达到一定量时溢过油坝,泄漏到轴承腔中。

In order to find the cause of oil loss of an aero-engine intermediate bearing oil collector. The oil-air two-phase flow in the oil collector was studied by VOF model,a numerical method of multiphase flow. The flow field and oil movement in the oil collector were analyzed,and the effect of inner ring rotate speed on oil collecting efficiency was given. The results show that the higher the rotating speed,the lower the oil collecting efficiency. The flow in the oil collecting annulus is mainly in the circumferential direction,and the asymmetric swirling vortices appeared on the meridional surface of the annulus. The reason for the oil loss is that the oil is split into two branches of oil flow from the entry port and collided with the inner surface of the cage,one branch to the inside of the bearing,and the other to the leak port. The lubricating oil accumulated near the inner side of the oil dam is absense of force that drives the oil to the inner direction of the bearing. When the oil accumulated at the oil dam reaches a certain amount,the oil overflows the oil dam and leaks into the bearing cavity.