离子双电层动态输运特性及电场对液体油膜压力的影响

随着流体动压润滑向纳米尺度发展，离子双电层对润滑性能的影响不能忽视。考虑到润滑过程中摩擦副相对速度是可变的，提出一种考虑离子动态输运特性与流场及电场耦合的离子双电层润滑模型，分析摩擦副相对运动速度和Zeta电势差对润滑膜的影响。分析结果表明：摩擦副相对运动造成了电势不均衡分布，平衡电势偏向于运动壁面Zeta电势，且相对速度的增大加剧了不均衡性；Zeta电势差对润滑液体承载能力影响显著，当Zeta电势差从0开始增大时，双电层电黏度效应及润滑液体承载能力先增大后减小。提出的模型实现了速度可变的双电层润滑瞬态仿真，为变工况下的双电层润滑性能分析奠定理论基础。

Dynamic Characteristics of Electric Double Layer Lubrication and the Effect of Electric Field on Lubricating Film Pressure

With the development of hydrodynamic lubrication in nanoscale,the influence of the electric double layer on the lubrication performance become significant.Considering that the relative speed of the friction pair is time-dependent in the lubrication process,a physical model for lubrication with electric double layer effects that considers the effect of ion transport,fluid flow characteristics and electric field was presented,and the influence of the relative speed of the friction pair and the Zeta potential difference on the pressure of the lubricating film was analyzed.The results indicate that the relative movement of the friction pair results in an unbalanced distribution of the electric potential.The equilibrium electric potential is biased towards the Zeta potential of the moving wall,and the increase of the relative speed increases the level of imbalance.The Zeta potential has a significant effect on the bearing capacity of the lubricant,as the Zeta potential increases from zero,the electric viscosity and the bearing capacity of the lubricant first increases and then decreases.The proposed model realizes the transient simulation of electric double layer lubrication with variable speed,which lays a theoretical foundation for the dynamic performance analysis of electric double layer lubrication under dynamic working conditions.