航空发动机轴承腔气相速度场数值模拟

摘要

The airflow field in a typical aeroengine beating chamber has been calculated with the commercial computational fluid dynamics software CFX 11. 0, taking into consideration the sealing structure of the ventilation hole and the airflow state equations. Then the effects of erating conditions such as rotational speed, air inflow volume, gap of the bearing chamber, the the structural parameters and ophydraulic diameter of the bearing chamber on the air- flow states are analyzed. The calculation results show preliminarily but clearly that the air inflow, ventilation hole and compressible air property have significant influence on the airflow states of the bearing chamber. The nondi- mensional tangential velocity decreases along the radial direction of the bearing chamber, but the radial and axial velocities change in a complicated manner. The rotational speed of the rotor, airflow volume and the hydraulic diameter of the bearing chamber have great influence on the nondimensional velocity distribution.%考虑轴承腔密封间隙和排气孔结构,以及气相介质状态方程条件下,利用CFX软件数值计算了典型航空发动机轴承腔结构的气相流场。探讨了密封间隙和排气孔结构存在以及考虑气相介质状态方程对气相介质流动的影响,以及转子转速、进气量、轴承腔的液力直径等工况和结构参数对气相介质流动状态的影响。计算结果表明：考虑密封进气和排气孔结构以及气相介质的状态方程对气相介质流动速度分布影响较大;气相介质无量纲切向速度沿着轴承腔径向方向减小,而无量纲径向速度和轴向速度沿着径向方向变化较为复杂;转子转速、密封进气量和轴承腔液力直径对无量纲速度分布影响也较大而且很复杂。与有关文献计算结果的对比验证了本文提出的计算方法的可靠性和正确性。