Static Analysis of Flying Characteristics of the Head Slider by Using an Optimization Technique

Abstract

This paper suggests a method to predict the static solution for gas-lubricated slider bearings in a hard disk drive (HDD) by using an optimization technique. The modified Reynolds equation for the hydrodynamic lubrication theory under the slip condition is used to describe the compressible fluid flow within the gas bearing, and a factored implicit finite difference (FIFD) scheme is applied for pressure calculations. An optimization technique is employed to find the solution at which the forces and moments acting on the gas bearing are in a state of equilibrium. The proposed method is more general and robust than the conventional update schemes since it exploits the automatic update capability of the optimization technique instead of using an empirical approach, and may be more efficient than the transient FIFD approach since it directly searches for static solutions instead of tracking the time-dependent equations asymptotically to steady state. Results obtained for several typical head slider models are reported, showing the effectiveness of the proposed method.