油气润滑气液两相环状流流动特性分析

Research on Flow Characteristics of Air-oil Two Phase Annular Flow for Oil-air Lubrication

建立油气润滑气液两相环状流的数学模型,通过Fluent仿真,研究水平管内环状流的形成机制以及油气流速对其影响趋势。结果表明:气液两相流型随气相速度的变化,从分层流向环状流和雾状流转变,其中分层流向环状流的转变是附壁效应和气相涡旋流动的结果,环状流向雾状流的转变是气相撕裂油相形成细小油滴,并均匀混合的结果;在一定范围内最短进口长度和气速成正比关系。

The mathematical model of air-liquid two-phase annular flow for the oil-air lubrication was established. The formation mechanism of the annular flow in the horizontal pipe was studied, and its influence trend of the oil and air＇ s ve- locity was researched through the Fluent simulation. The results show that the flow pattern of the air-oil two-phase changes with air velocity, changing from stratified flow to annular flow, then to fog flow. The transition from the stratified flow to an- nular flow is due to the wall attachment effect, and the transformation of the annular flow to the fog flow is the result of the air phase＇ s tearing the oil phase into small droplets, and in uniform mixing. The relationship is positive correlation between the shortest length of the inlet and the air velocity in a certain range.