摘要
轴承腔的润滑和换热设计依赖于对腔内油气两相流动和换热状态的准确理解。针对先前研究工作的不足,在包含油滴碰撞腔壁热量交换、沉积热量以及油膜温度即考虑温度效应的条件下,开展了油滴沉积特性及油膜流动特征分析。首先分析了单个油滴碰撞腔壁沉积特性,确定了油滴的沉积质量、动量和热量。其次在考虑油滴尺寸分布的条件下,通过离散油滴尺寸范围的方式确定了腔内所有油滴碰撞腔壁的沉积油膜质量、动量和热量。最后借助力学平衡和质量守恒条件,以上述参数为基础计算了腔壁油膜温度以及速度和厚度的分布情况。计算结果表明,随着转子转速的增加,油滴的质量、动量和热量沉积率有所降低,一次沉积油膜质量、沉积油膜动量、沉积油膜热量以及油膜速度均有所增加,而油膜厚度降低。通过与试验数据的对比表明,提出的轴承腔油滴沉积特性及油膜流动特征分析方法是较为可靠的,并且考虑温度效应使油膜厚度的计算更为准确。分析工作为轴承腔的润滑和换热设计提供了一定的参考依据。
The lubrication and heat transfer designs of an aero engine bearing chamber depend on the understanding about the states of oil/air two-phase flow and heat transfer in chamber.To overcome the weakness of previous study,we investigates into the characteristics of oil droplet deposition and oil film flow in a bearing chamber considering the heat transfer of oil droplet/housing interaction,deposition heat and oil film temperature,namely,the effect of temperature.Firstly,the deposition characteristics of a single oil droplet are analyzed,and the deposition mass,momentum and heat are obtained.Secondly,with the oil droplet size distribution,the deposition oil film mass,momentum and heat of all the droplets impacting on housing are obtained by dispersing the diameter range of the droplets.Finally,with the above parameters,the oil film temperature,average velocity and thickness are calculated by means of force balance and mass conservation conditions.The results show that with an increasing shaft speed,the oil droplet deposition rates of mass,momentum and heat decrease,and the first deposition oil film mass,deposition oil film momentum,deposition oil film heat and oil film velocity increase,while oil film thickness decreases.The comparison of oil film thickness between theoretical data and experimental data shows that the proposed theoretical model is reliable and the consideration of temperature effect improves the calculation accuracy about oil film thickness.The present work provides some references for the design of bearing chamber.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2016年第10期3159-3169,共11页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(51275411)~~
关键词
航空发动机
轴承腔
油滴
沉积
油膜
对流换热
温度
aero engine
bearing chamber
droplets
deposition
oil film
heat transfer
temperature
