滑动轴承润滑油膜单气泡破裂扩散的仿真分析

Simulation Analysis of Single Bubble Rupture Diffusion of Lubrication Oil Film of Sliding Bearing

滑动轴承在工作过程中由于供油压力不足、机械故障等原因,可能会因贫油而出现油膜气泡现象,导致承载力下降或油膜破裂。利用气液两相流的基础理论和数值模拟分析技术,针对滑动轴承润滑油膜中含有单个大气泡的现象,建立物理模型、数学模型及相应的初始和边界条件,利用VOF模型分析气泡的动力学行为,对于大气泡裂变的过程、破裂后子气泡的演变过程进行仿真。结果表明:轴承油膜中出现的大气泡,在工作过程中极易发生非对称性破裂,裂变成直径大小不等的子气泡;轴承工作过程中,在离心力的作用下气泡有向轴承外圈靠近的趋势,并且有些气泡黏附在轴承外壁上;轴承转速越高,气泡破裂得越快。

Sliding bearing oil film bubble phenomenon possible appears due to the insufficient oil pressure or mechanical failure during operation, which will result in the decline of loading capacity or the oil film rupture. Based on the basic theory of gas-liquid two phase flow and the numerical simulation techniques, the physical model and mathematical model, the corresponding initial and boundary conditions were established aimed the phenomenon of lubricant film in sliding bearing containing a single large bubble. The bubble dynamic behavior was analyzed by using the VOF model, the fission process of large bubble, and the evolution process of the subbubble were simulated. The results show that the non symme- try rupture occurs easily for the large bubble in bearing oil film in working process, and the subbubbles with different sizes in diameter are formed. The bubble is close to the outer ring of the bearing under the action of centrifugal force in working process, and some bubbles are adhered in the bearing outer wall. The bubble ruptures faster, when bearing speed is faster.