论文部分内容阅读
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 design of the bearing cavity relies on an accurate understanding of the two-phase flow and heat transfer conditions in the cavity. In view of the shortcomings of previous research work, the characteristics of droplet deposition and the characteristics of oil film flow were studied under the conditions of heat exchange, deposition heat and temperature of oil film, which were caused by collision of oil droplet collision wall. First, the deposition characteristics of a single droplet collision cavity wall were analyzed to determine the deposition quality, momentum and heat of oil droplet. Secondly, the mass, momentum and calorific value of the deposited oil film on the wall of the collision chamber were determined by the size range of discrete oil droplets under the condition of considering the oil droplet size distribution. Finally, with the aid of the mechanical equilibrium and the mass conservation conditions, the distribution of cavity wall oil temperature, velocity and thickness was calculated based on the above parameters. The results show that with the increase of rotor speed, the mass, momentum and heat deposition rate of oil droplets decrease. The first depositional film quality, the depositional oil film momentum, the deposition oil film heat and the oil film velocity all increase while the oil film thickness decreases. The comparison between the experimental data and the experimental data shows that the proposed oil droplet deposition characteristics of the bearing cavity and the method of characteristic analysis of the oil film flow are more reliable, and the calculation of the oil film thickness is more accurate considering the temperature effect. Analytical work provides some reference for lubrication of bearing cavity and heat exchange design.