轴承腔油滴含率及油滴相与空气能量传递分析  

Oil droplets fractions and oil droplets/air energy transfer analysis in bearing chamber

作　　者：孙恒超[1] 陈国定[1] 王莉娜[1] 王菲[1] 

机构地区：[1]西北工业大学机电学院,西安710072

出　　处：《航空学报》2016年第3期1060-1073,共14页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(51275411)~~

摘　　要：为了改善迄今轴承腔油滴运动分析未包含油滴与空气热量传递以及油滴相/空气介质均相处理中油滴含率确定方式不够准确的不足,借助单个油滴运动分析和油滴尺寸分布提出了轴承腔油滴含率及油滴相与空气能量传递分析方法。首先在考虑单个油滴与空气对流换热条件下,将油滴能量方程嵌入运动方程,并同步离散求解油滴运动方程和能量方程,实现了单个油滴运动速度和温度的联立求解,通过与试验结果对比证明考虑温度效应有助于提升油滴速度计算的准确性;然后确定了轴承腔油滴尺寸分布,并离散油滴尺寸分布范围以及轴承腔流场空间,进行油滴运动分析确定了轴承腔不同径向位置处油滴的体积和质量含率及油滴相与空气的动能和热能传递量。构建了圆盘腔油滴含率试验台,开展了油滴体积含率的试验测量,理论计算值与试验值较为吻合,验证了轴承腔油滴含率分析方法的有效性。Previous investigation of oil motion in bearing chamber has not considered the heat transfer between oil droplet and air,moreover,the determination of oil droplet fraction is lack of accurity when treated the oil droplets and air as homogeneous phase.To overcome the above limitations,this paper proposes the analytical method of oil droplets fractions and oil droplets/air energy transfer in bearing chamber by virtual of calculating both oil droplet motion and droplet size distribution.Firstly,considering the heat convection between oil droplet and air,the oil droplet thermal equation is embedded into its motion equation.The associated equations are solved simultaneously by an instantaneous step method to obtain the velocity and temperature of oil droplet.This treatment of considering oil droplet/air heat transfer can enhance the accuracy of droplet velocity by comparison of theoretical and experiment results.Secondly,the oil droplet diameter probability density function and the frequency of droplets generation in bearing chamber are obtained;by dispersing droplet diameter range and oil droplets/air mixture flow field,the oil droplets fractions and energy transfer with air at different radial positions are calculated by oil droplet motion analysis.Lastly,a rotating disk chamber test rig is established to investigate oil droplets＇ volume fraction.The measurement of oil droplets volume fraction is carried out.The proposed theoretical model is validated by experimental results.Such improved model overcomes the shortages of previous study,which failed to take account of the oil droplet/air heat transfer in oil droplet motion,as well as the oil droplets fraction has less accuracy among the oil droplets/air homogeneous flow simulation.

关 键 词：航空发动机 轴承腔 液滴 液滴尺寸分布 对流换热 含率 热能 动能 

分 类 号：V233.4[航空宇航科学与技术—航空宇航推进理论与工程]