两刚性圆球间双黏度流体挤压流动压力分析

Analysis of squeeze flow of bi-viscosity fluid between two rigid spheres

颗粒物质是大量固体颗粒相互作用而组成的复杂体系。颗粒间孔隙水具有复杂连通结构和复杂的流动规律,直接影响颗粒体系的变形和强度,目前颗粒间隙液体的挤压流动和剪切运动分析是流体力学的难点。基于Reynolds润滑理论,导出了存在填隙双黏度流体时,两刚性圆球间流体的挤压流动速度场和压力方程。根据应力的变化情况,将流体分为屈服区和未屈服区,讨论了两区厚度与流体及颗粒参数的关系,分析了流体压力分布随计算参数的变化规律,得到了法向挤压黏性力的积分表达式,并给出了黏性力随不同参数的变化规律。

Granular matter is a collection of a large number of interactive solid particles.For moist granular systems,such as unsaturated soils,interstitial liquid among particles forms complicated connection structures and displays unique flow behaviours,which affect the strength and deformation of moist granular systems.At present,squeeze flow and shear flow between particles with fluid are hard to analyze in fluid mechanics and granular system mechanics.Based on the Reynolds lubrication theory,squeeze flow between two arbitrary rigid spheres with an interstitial bi-viscosity fluid is studied,and the yield surface paradox is avoided.According to the characteristics of stress distribution,the fluid is divided into both yielding and unyielding regions.Along with the variation of parameters,differences between the thicknesses of the two regions are discussed;and the pressure distribution in these regions is analyzed.Furthermore,the change law of the pressure distribution of the fluid and an integral expression of viscous force are derived.