滑滚表面间的流体膜壁面滑移和流体动力学(英文)

Wall slip and hydrodynamics of a fluid film between sliding-rolling surfaces

经典雷诺润滑理论建立在无壁面滑移的假设基础之上。近年来许多试验报告了发生在流体膜流动的壁面滑移证据。本文研究了两固体表面间的流体膜流动特性和流体动力学,发现壁面滑移显著影响膜的流体动力学问题,流体动压力不仅受黏度和几何间隙的影响,而且还由壁面滑移和表面运动强力控制,通过控制表面的吸附性质,甚至可以得到零摩擦表面。另一方面,如果两个表面具有相同的滑移特性,存在一个临界滑动速度使得流体动压效应完全消失;但是在纯滚动条件下,即使界面极限剪应力很小,仍然有相当可观的流体动压效应。

The classical Reynolds lubrication theory is based on the no wall-slip assumption. During the recent years many experiments reported evidences of wall slip occurring in a fluid film flow. The flow behavior and hydrodynamic response of a fluid film confined between two solid surfaces are studied in the present paper. It is found that wall slip dramatically affects hydrodynamics of the fluid film. The hydrodynamic pressure is not only affected by the fluid viscosity and gap geometry, but also strongly controlled by wall slip and by what a surface moves. By controlling the surface adhesion property, even a zero friction surface can be obtained. On the other hand, if the two surfaces of a sliding gap have the same slip property, a critical sliding speed exists for the fluid hydrodynamic response to totally disappear. In pure rolling, however, a considerable hydrodynamic response still exists even the surface limiting shear stress is small.