磁盘速度与容纳系数对硬盘气膜静态特性的影响

Effects of Disk Velocity and Accommodation Coefficients on Static Characteristics of Air Bearing Films in Hard Disk Drives

随着硬盘(Hard disk drives,HDDs)中浮动块与磁盘间飞行高度的降低,气体分子与磁头/磁盘间的交互作用逐渐增强,磁盘速度及容纳系数(Accommodation coefficients,ACs)对气膜承载特性的影响越来越重要。采用一种无网格法—最小二乘有限差分(Least square finite difference,LSFD)法,对简化的分子气膜润滑(Molecular gas film lubrication,MGL)方程进行求解,研究了磁盘速度、磁头和磁盘表面ACs对HDDs超低飞高气膜静态特性的影响。数值结果表明:对称性分子交互作用时,磁头和磁盘表面ACs对气膜静态特性的影响明显;非对称性分子交互作用时,磁盘表面ACs对气膜静态特性的影响较大,而磁头/浮动块表面ACs的影响较小;不同ACs条件下,随着磁盘速度或最小飞行高度的增加,压力幅值点位置的变化较均匀。

As the spacing between the flying head/slider and the rotating disk in hard disk drives （HDDs） continues to decrease, the interaction between the molecular gas and the surfaces of the disk and the head/slider becomes significant. The influence of disk velocity and accommodation coefficients （ACs） at slider and disk surfaces are important factors to govern the static characteristics of air bearing films. A simplified molecular gas film lubrication （MGL） equation is solved by using a mesh-less method, called least square finite difference （LSFD） method. Effects of the ACs on static characteristics of the air bearing film in HDDs with different disk velocities and ultra-low flying heights are investigated. Numerical results show that effects of ACs at slider and disk surfaces on the static characteristics are obvious for the case of symmetric molecular interaction. The effects of ACs at the disk surface on the static characteristics are obvious for the case of non-symmetric molecular interaction, while effects of ACs at the slider surface on the static characteristics are weak. The position of the maximum pressure changes uniformly with the increase of the disk velocity or the minimum flying height under different conditions of ACs.