表面织构活塞环与CuO纳米润滑油协同润滑特性数值研究

建立了活塞环-缸套流体动压润滑数值模型,研究表面织构和CuO纳米润滑油对活塞环协同润滑机理。研究结果表明:CuO纳米润滑油能有效减小粗糙接触力,降低磨损,但会引起流体黏性剪切力增加;活塞环织构表面与缸套之间形成的微动压效应对动压润滑有促进作用,能有效减小流体摩擦力,减少摩擦损失,但在上下止点附近会导致粗糙接触力增加,磨损加剧;活塞环表面织构的位置会影响其摩擦性能,对比发现中间织构效果最好,与无织构活塞环相比能减小摩擦损失5.17%;表面织构和CuO纳米润滑油之间存在协同润滑作用,合适浓度的纳米润滑油和一定尺度的表面织构能在减少活塞环摩擦损失的同时降低磨损。本研究中中间织构活塞环和体积分数0.5%CuO纳米润滑油组成的协同润滑能达到最佳润滑性能。

Numerical Study on Synergistic Lubrication Characteristics of Textured Ring and CuO Nano-Lubricant

A numerical model of ring-liner hydrodynamic lubrication was established to study the synergistic lubrication mechanism of surface texture and CuO nano-lubricant.The results show that CuO nano-lubricant can decrease asperity contact force and reduce wear,but will increase viscous shear force of fluid.The formed wedge-shaped oil film effect between the texture surface of the ring and the liner can promote the hydrodynamic lubrication and effectively reduce the hydrodynamic friction force and thereby reduces the friction loss.However,the asperity contact force increases and the wear intensifies near top and bottom dead centers.The position of surface texture forthe ring affects the tribological performance and the ring textured in the middle has the best effect,which can reduce the friction loss by 5.17% compared with the untextured ring.In addition,there is a synergistic lubrication effect between the surface texture and the CuO nano-lubricant.A suitable concentration of nano-lubricant and a certain scale of surface texture can reduce the friction loss and the wear of piston ring.In this research,the synergistic lubrication consisting of the ring textured in the middle and the nano-lubricant with 0.5% volume of CuO achieves the optimum lubrication performance.