考虑油滴变形和二次油滴效应的轴承腔壁面油膜流动分析
收稿日期: 2012-10-22
修回日期: 2013-01-29
网络出版日期: 2013-02-01
基金资助
国家自然科学基金(50975233,51275411)
Flow Characteristics Analysis of Wall Oil Film with Consideration of Oil Droplet Deformation and Secondary Oil Droplet Deposition in Aeroengine Bearing Chamber
Received date: 2012-10-22
Revised date: 2013-01-29
Online published: 2013-02-01
Supported by
National Natural Science Foundation of China(50975233,51275411)
航空发动机轴承腔油气两相流动状态下的壁面油膜分布和流动速度直接影响其润滑和换热特性。考虑油滴变形和二次油滴沉积效应作用,通过油滴变形和运动、油滴/腔壁碰撞过程质量和动量转移以及二次油滴运动和沉积分析,获得油滴沉积过程的质量和动量转移;在此基础上利用根据力平衡原理和质量守恒原理建立的壁面油膜分布和流动的力学模型获得壁面油膜的厚度和速度分布。分析和探讨了油滴变形对油滴速度和运行轨迹的影响,变形和二次沉积效应对油滴质量和动量转移以及壁面油膜厚度和速度分布的影响。计算结果表明:考虑变形后油滴所受阻力增加,其运动速度减小,运行轨迹更加弯曲,一次质量转移增加,一次动量转移减小;二次油滴的数量很大,其沉积质量和动量转移是轴承腔中油滴质量和动量转移的主要部分;油滴变形和二次沉积效应作用下壁面油膜的厚度和流动速度都明显增大,润滑油加速排出。
陈薄 , 陈国定 , 王涛 . 考虑油滴变形和二次油滴效应的轴承腔壁面油膜流动分析[J]. 航空学报, 2013 , 34(8) : 1980 -1989 . DOI: 10.7527/S1000-6893.2013.0119
The thickness and velocity profiles of a wall oil film under air/oil two-phase flow conditions in an aeroengine bearing chamber have a strong and direct influence on the performance of lubrication and heat transfer of the chamber. This paper takes into consideration the deformation of primary oil droplets and the deposition of secondary oil droplets, and then determines the mass and momentum transfers in the process of deposition of oil droplets. The analysis contains droplet deformation and motion, mass and momentum transferred to the wall film with impingement of droplets/wall, and motion and deposition of secondary oil droplets. Based on the knowledge so obtained, the wall film thickness and velocity are subsequently calculated using a film flow model established by force balance and mass conservation. The effect of deformation on droplet velocity and trajectory is analyzed, and the effects of deformation and secondary droplet deposition on mass and momentum transfers and wall film thickness and velocity are discussed. The calculation results show preliminarily that droplet velocities decrease and trajectories become more bent due to the effect of deformation. When taking no account of secondary oil droplet deposition, the mass transfer of deformation droplets increases and the momentum transfer decreases in relation to those of spherical droplets. The number of secondary oil droplets is much larger, and the total mass and momentum transfers are mainly obtained from the secondary deposition. Film thickness and velocity increase significantly due to the influence of droplet deformation and secondary deposition, and lubrication oil is accelerated to exit the chamber through the seavenge port.
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