表面形貌对磁盘-磁头间隙润滑影响的数值分析

Numerical analysis of the influence of surface topography on head-disk lubrication

为了解决传统R eyno lds方程无法求解盘片表面形貌突变处压力分布的问题,采用N-S方程和有限体积法对磁盘磁头间隙润滑进行数值分析。使用形貌突起高度、密度和占空比3个参数描述盘片表面的规则矩形横向形貌,并通过分析流场压力和速度的分布,解释了不同形貌参数对润滑阻力的影响。结果显示,由于矩形形貌的影响,形成了压差阻力,压差阻力随形貌突起高度或密度的增加而增大,随突起占空比的增加而减小。摩擦阻力的大小取决于近壁面流场的速度梯度,而形貌参数是该速度梯度的决定因素之一。压差阻力和摩擦阻力的综合作用决定了盘片表面的总阻力。

The conventional Reynolds lubrication equation cannot accurately predict the pressure distributions for disk surfaces with sharply changing topographies. Therefore, the Navier-Stokes equations were solved using the finite volume method to numerically analyze the head-disk lubrication for disks with regular rectangular transverse bulges on the disk surface which were characterized by the bulge height, density and duty ratio. The numerical results show that the velocity and pressure distribution changes caused by the different surface parameters greatly affect the lubrication. The difference between the front and back bulge edges results in pressure drag which increases with increasing bulge density and height, and with decreasing duty ratio. The friction drag determined by the velocity gradient near the wall is also affected by the surface topography. The total drag consists of the pressure and friction drags.