压力相关的壁面滑移在滑动间隙流体动压力产生中的作用

近年来,壁面滑移在纳米流变学、微流体力学、薄模润滑和微机电系统(MEMS)等领域越来越引起关注。以前大部分研究集中于表面初始极限剪应力对薄模润滑的壁面滑移和流体动力学的影响。本文通过一个极限剪切应力比例系数主要研究了与压力相关的壁面滑移滑动间隙流体动压力产生中的作用,发现极限剪切应力比例系数以相反的两种方式影响着流体膜的流体动力学:在高初始剪应力区使流体动力增加,但在低初始剪应力区使流体动力减小,这意味着就极限剪切应力比例系数影响流体动压力而言,存在一个初始极限剪切应力的转换点。但是在界面滑移存在时,较小的极限剪切应力比例系数总是产生较小的摩擦阻力。

The role of pressure-dependent wall slip in the generation of hydrodynamic pressure in a sliding gap

Wall slip has received more and more attention during recent years in nanorheology,micr-fluidics,thin film lubrication,micro-electro-mechanical-system(MEMS),etc.Most of the previous investigations focused on the effects of the surface initial limiting shear stress on the wall slip behavior and hydrodynamics of thin film lubrication.This paper mainly investigates the role of the pressure-dependent wall slip in the generation of hydrodynamic pressure in a sliding gap by means of a limiting shear stress proportional constant.It is found that the proportional constant affects the hydro dynamics in two opposite ways: it increases hydrodynamic pressure at a high initial limiting shear stress,but decreases hydrodynamic pressure at a low initial limiting shear stress.That means there is a transition point of the initial limiting shear stress for the proportional constant to affect generation of the hydrodynamic pressure.However,a small proportional constant always gives rise to a low friction drag when a wall slip occurs.