以球形CuO纳米颗粒为润滑油添加剂，选取合适的纳米润滑油密度、粘度等物性参数模型。在此基础上，建立某型16V船用柴油机曲轴主轴承流体润滑数值模型，对比分析不同体积分数纳米润滑油对曲轴主轴承最小油膜厚度、最大油膜压力及摩擦损失功率等润滑性能的影响。计算结果表明，纳米颗粒的加入，增加了润滑油粘度，提高了润滑油承载能力。相比基础润滑油，纳米润滑油明显增加了主轴承最小油膜厚度。标定工况下，当纳米润滑油体积分数为2%时，最小油膜厚度最大增加了3.4倍。而纳米润滑油对曲轴主轴承摩擦损失的影响则取决于主轴承润滑状态。当主轴承负载较大，润滑状况较为恶劣时，相比基础滑油具有更好的减摩特性。而当负载较小，润滑状况良好时，由于黏性流体剪切力增加导致总摩擦损失增大。通过对曲轴主轴承整体性能分析发现，纳米润滑油体积分数对曲轴主轴承总摩擦损失的影响并非越高越好，而是存在一最优值。
With spherical CuO nanoparticles as lubricant additives, suitable physical parameters such as density and viscosity of nano-lubricant were selected. On this basis, a numerical model of main bearing hydrodynamic lubrication for a 16V diesel engine was established, and the effects of different volume fractions of nano-lubricants on the lubrication performance of crankshaft main bearing, such as minimum oil film thickness, maximum oil film pressure and friction loss power, were compared and analyzed. The results show that the addition of nanoparticles increases the viscosity of lubricating oil and the load-carrying capacity of lubricating oil. Compared with the lubricant without nanoparticles, nano-lubricants significantly increase the minimum oil film thickness of main bearings. Under calibration conditions, when the volume fraction is 2%, the maximum increase is 3.4 times. The influence of nano-lubricant on friction loss of main bearing depends on the lubrication state of friction pair. When the load of main bearing is heavy and the working condition is worse, the wear reduction performance is better than that of lubricant without nanoparticles, while when the load is smaller and the lubrication condition is well, the total friction loss increases with the increase of viscous fluid shear force. Through the analysis of the overall performance of crankshaft main bearing, it is found that the influence of nano-lubricant volume fraction on the total friction loss of crankshaft main bearing is not the higher the better, but there is an optimal value.
2021,43(11): 122-127 收稿日期：2021-04-19
DOI：10.3404/j.issn.1672-7649.2021.11.023
分类号：TK428.9
作者简介：王焕杰(1981-)，女，博士，副教授，研究方向为摩擦学及表面工程，船舶动力
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