Numerical study on motion characteristics of lubricating oil film of bearing chamber wall

To obtain the motion characteristics of lubricating oil film of aero-engine bearing chamber wall, oil droplet motion in the bearing chamber, droplet impacts with the chamber wall and oil film flow were studied, and a complete mathematical model was established based on some assumptions. Three-dimensional unsteady numerical simulation to solve oil film flow by using Star-CD commercial software was carried out. On the basis of verifying the rationality of the mathematical model, the motion characteristics of two-phase flow in the bearing chamber with the rotation speed was analyzed and studied. The results show that the oil film on the bearing chamber wall experiences a development process from the oil film formation to basic stability. And in the stable state, with the increasing of rotation speed, oil film thickness shows a trend of decreasing, while oil film circumferential velocity shows a trend of increasing, in which the increment of the oil film momentum by the oil droplets' impingement is the main reason. Moreover, the shear force between air and oil film has the postive effect on accelerating the oil film velocity.The higher the rotation speed, the effect is more significant.