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航空发动机的润滑系统和二次空气流动系统的设计依赖于对轴承腔中复杂的油气两相流动状态的理解,这其中包括影响轴承腔润滑和换热性能的壁面油膜物理特性。运动油滴转移的质量和动量与轴承腔壁面油膜厚度和速度有很大关系,并决定轴承腔油气两相流动的油膜初始状态。通过分析轴承腔结构工况与油滴直径分布参数关系,明晰基于直径尺寸连续的油滴质量分布,在此基础上进行油滴与轴承腔壁面碰撞后的沉积质量和转移动量的计算,以量纲一参数的形式探讨轴承腔结构和工况对油滴沉积质量和转移动量的影响。针对某一轴承腔结构和工况条件进行的油滴沉积质量和动量转移量计算,以研究计算方法的可行性。结合油滴尺寸分布进行油滴沉积特性分析,探索轴承腔油膜形成过程的物理本质,获得表征轴承腔结构和工况条件的量纲一参数W e*1/2对油滴沉积质量和沉积油膜动量转移量的影响规律,有助于航空发动机轴承腔油气两相流动研究后续工作的开展。
The design of aero-engine lubrication systems and secondary air-flow systems relies on an understanding of the complex oil-gas two-phase flow conditions in the bearing chamber, including the physical properties of the wall oil film that affect the lubrication and heat transfer performance of the bearing chamber. The quality and momentum of the movement of oil droplets have a great relationship with the film thickness and velocity of the wall of the bearing cavity and determine the initial state of the oil film flowing through the oil and gas in the bearing cavity. By analyzing the relationship between the working condition of bearing cavity and the diameter distribution of oil droplet, the mass distribution of oil droplet based on the continuous diameter dimension is clarified. On this basis, the calculation of sedimentation mass and transfer momentum after collision of oil droplet and bearing cavity wall is carried out. The effect of bearing cavity structure and working conditions on the deposition quality and transfer momentum of droplet is discussed in the form of a parameter. The calculation of droplet deposition mass and momentum transfer for a bearing cavity structure and working conditions was carried out to study the feasibility of the calculation method. Combined with the oil droplet size distribution, the deposition characteristics of oil droplets were analyzed to explore the physical essence of oil film formation in bearing cavity. The dimension parameter W e * 1/2 which characterizes the bearing cavity structure and working conditions was obtained. The influence law of momentum transfer is helpful to carry out the follow-up work on the study of oil-gas two-phase flow in aeroengine bearing cavity.