基于滑移/非滑移异质界面的动压润滑性能优化

Performance optimization of hydrodynamic lubrication based on heterogeneous slip/no-slip surface

合理布置的滑移/非滑移异质界面可以提高流体动压润滑性能,但目前滑移区和非滑移区的组合方式大多采用单一的直线拼接法,没有针对流体润滑摩擦副的各类工况设计出相应的优化方案,为此本文建立了一组离散式二次方程来描述滑移区和非滑移区拼接轨迹,并引入计算域单元的宽长比作为优化变量,分别以液膜刚度和摩擦因数作为优化目标,通过MATLAB数值仿真求解不同宽长比条件下滑移区和非滑移区的最优拼接轨迹。结果表明,与直线拼接法相比,选取二次方程所描述的抛物线作为滑移区和非滑移区拼接轨迹的方法使流体润滑摩擦副在摩擦因数和液膜刚度等性能指标上都有所改善,而且根据不同的优化目标参数可以方便地绘制出最优拼接方案,验证了本文方法在改善动压润滑性能上的可行性和普适性。

Well-arranged heterogeneous slip/no-slip surface can improve the performance of hydrodynamic lubrication.But the existing combination mode between the slip and no-slip zones is a simple way of straight-line splicing which cannot give the best scheme for fluid-lubricated friction pairs at different working conditions.So this paper formulated a set of discrete quadratic equations to describe the splicing trajectory between the slip and no-slip zones,and introduced aspect ratio of the computational domain as the optimization variable,liquid film stiffness and friction coefficient as the optimization objectives,respectively.Then the optimal slip/no-slip zones splicing trajectories at different aspect ratios were obtained by MATLAB numerical simulation.The results show that,compared with the straight-line splicing,this method of choosing the parabola described by the quadratic equations as the splicing trajectories between the slip and no-slip zones optimizes such performance indexes of fluidlubricated friction pair as the friction coefficient and stiffness of the liquid film.Moreover,according to different optimization objective parameters,the optimized splicing scheme can be easily drawn,which proves the feasibility and universality of the proposed method for the improvement of hydrodynamic lubrication performance.