航空发动机轴承腔含油滴油气两相介质的流动模拟

Exploring through Numerical Simulation Lubrication Flow inside an Aeroengine Bearing Chamber with Film/Droplet/Air Interactions Taken into Consideration

航空发动机轴承腔设计正确性不仅影响到发动机转子的力学性能和工作寿命,而且影响到发动机二次空气流动系统的效率。轴承腔中油气两相介质共存的复杂状态使得轴承腔润滑设计和热分析十分困难,并因此影响发动机润滑系统和二次空气流动系统设计准确性。针对较宽结构和工况范围内出现的轴承腔中油膜、油滴和空气共存的流动形态,文章基于CFX商业软件平台进行了轴承腔润滑介质流动状态数值模拟,探讨了轴承腔结构和工况对腔中介质流动性态和参数的影响,揭示了若干工况条件下的润滑介质压力和速度的分布规律。研究有助于轴承腔油气两相流动物理本质的深入理解,亦为航空发动机轴承腔设计中的工程基础数据和参数获得,提供了手段和途径。

Aim. The introduction of the full paper reviews some papers in the open literature, points out what we believe to be their shortcoming and then proposes our exploration, which is explained in sections 1 and 2. Section 1 briefs the structure of an aeroengine bearing chamber and its parameters. Subsection 2. 1 explores mathematically the oil film/air （containing droplets） two-phase flow inside an aeroengine bearing chamber; subsection 2. 2 devel- ops a numerical model for predicting the lubricant flow inside an aeroengine bearing chamber, with film/droplet/air interactions taken into consideration. Section 3 uses the CFX commercial software to simulate the pressure and ve- locity distributions of lubricant flows under certain operation conditions; the simulation results, given in Figs. 2 through 7, and their analysis show preliminarily that ： （ 1 ） there is a wider pressure distribution of the lubricant flow along the circumference of the beating chamber than along its axial direction ; the velocity distribution is just the op- posite of the pressure dis sure inside the bearing c tribution ; （2） the pressure of oil film increases with increasing rotational speed ;. the preshamber increases with increasing oil mass flow rate and sealing air.