﻿ 基于CFD的船用柴油机滑动轴承油膜稳定性研究
 舰船科学技术  2022, Vol. 44 Issue (16): 94-96    DOI: 10.3404/j.issn.1672-7649.2022.16.018 PDF

Research on oil film stability of sliding bearing of marine diesel engine based on CFD
ZHANG Cheng, LEi Jun, FU Bo-feng, GUO Lu-ming, ZHAO Zhan-hang, WEI Yan-xia, LEI Jiao-jiao
Shanxi Diesel & Engine Heavy Industry Co., Ltd., Xingping 713100, China
Abstract: Based on the hydrodynamic lubrication theory of sliding bearing, a three-dimensional CFD model of oil film of sliding bearing is established, and the calculation domain is discretized by using structured grid. In order to study the influence of oil film pressure on the stability of sliding bearing, the Fluent software is used through RNG κ-ε. The turbulent model is used to calculate the oil film flow field, and the three-dimensional distribution of oil film pressure field is simulated under different rotational speeds and different inlet pressures. The calculated results show that as the journal begins to rotate anticlockwise, there are high pressure area and low pressure area on both sides of the minimum oil film thickness, and the high pressure area and low pressure area increase gradually with the increase of rotational speed. At the same speed, the oil inlet pressure increases, and the high pressure area gradually diffuses to the oil inlet hole until it connects with the low pressure area. This method provides a theoretical basis for the study of oil film stability of sliding bearing.
Key words: sliding bearing     oil film pressure     numerical simulation     CFD
0 引　言

1 工作原理

 图 1 动压滑动轴承 Fig. 1 Hydrodynamic sliding bearing

2 数值计算与分析 2.1 几何模型

 图 2 油膜几何模型 Fig. 2 Geometric model of oil film

 图 3 油膜整体网格 Fig. 3 Oil film global mseh

 图 4 油膜局部网格放大 Fig. 4 Local mesh enlargemengt of oil film
2.2 数值计算分析

 图 5 不同转速下油膜压力场分布 Fig. 5 Distribution of oil film pressure at different rotating speeds

 图 6 不同转速下压力极值变化 Fig. 6 Variation of pressure extremum at different speeds

 图 7 不同进油压力下油膜压力场分布 Fig. 7 Distribution of oil film pressure at different inlet pressure
3 结　语

1）对油膜模型进行CFD数值模拟，得到油膜压力场的分布，在最小油膜厚度处两侧分别呈现高压区和低压区，即楔形收敛区和发散区。随轴颈逆时针旋转，润滑油从进油口进入楔形收敛区，油膜压力逐渐增大，当到达最小油膜厚度处，进入发散区，油膜压力迅速减小，形成低压区后逐渐稳定。

2）随转速增加，高压区和低压区逐渐在增加，最大正压和最大负压均逐渐增大，两者增长速率均趋于稳定，呈线性增长，最大负压的增长速率高于最大正压。

3）随进油压力增加，高压区逐渐向进油孔位置扩散，直至与低压区相接，且进油压力越大，与进油口相对应位置的压力越大，最大高压和最大负压位置基本保持不变。

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