甩油盘系统内部流场数值模拟

Numerical Simulation of Fluid Field Inside Slinger System

关键词:  甩油盘  分油环  数值模拟  内部流场  雾化

Key words:  Slinger  Oil ring  Numerical simulation  Inside fluid field  Atomization

摘要:

为获取内部流场对雾化性能的影响规律，对实际应用的甩油盘系统，包括分油环、甩油盘进行了数值模拟研究。结果表明，分油环中，流量越大，分流均匀性越差；合适的出口直径可以提升分油环分流均匀性；出口数量越多，分流均匀性越差，数量增加到一定程度时，分流均匀性又会转好；不同位置的出口流量不同，最大流量偏差约2%；出口直径不一致时，分流均匀性最差。在甩油盘研究中，引入了出口液体等效直径的概念来量化研究内部流场对雾化的影响。研究得到，转速增加，甩油盘内部液膜变薄，液雾SMD减小，均匀性变好，穿透深度变小；流量增加，液雾SMD变大，穿透深度增加；出入口之间轴向距离引起出口液体速度及液体等效直径的变化小于5%，可以忽略其影响；在出孔直径小于1.7mm时，增大出孔直径，可以改善雾化；出孔倾斜角主要影响液雾的轴向分布；增加出孔数量，可以减小液雾SMD。

Abstract:

To obtain how the internal flow affects the atomization performance， the slinger system which includes oil ring and slinger was studied by numerical simulation. In the oil ring， greater flow rate causes poorer flow distribution uniformity. The appropriate outlet diameter can improve the flow distribution uniformity. Larger number of outlets breaks the distribution uniformity of the flow， but when the number increases to a certain value， the flow distribution will be more even. The outlet flow rates are different when at different locations， the maximum flow deviation is about 2%. The flow distribution uniformity is poorest when the outlet diameters are inconsistent. In the research of slinger， a concept of liquid equivalent diameter was introduced to quantitatively measure the effects of the internal flow on slinger’s atomization. The results show that when the rotating speed increases， the liquid film inside the slinger becomes thinner， the spay SMD becomes smaller and more uniform， and the penetration depth becomes smaller. When the flow rate increases， the spray SMD becomes larger and the penetration depth increases. The axial distance between the inlet and the outlet causes the change of the liquid velocity and the liquid equivalent diameter at outlet to be less than 5%， and the effect can be ignored. Increasing the outlet diameter can improve the spray quality when the outlet diameter is smaller than 1.7mm. The outlet channel angle mainly affects the axial distribution of the spray. Increasing the outlet number can reduce the spray SMD.