An adaptive finite element strategy for analysis of air lubrication in the headdisk interface of a hard disk drive

Abstract

In this paper a finite element solution of the modified Reynolds equation using isoparametric, bilinear quadrilateral elements with an adaptive meshing strategy is presented. The modified hydrodynamic stiffness method (Smith, 1995) was used to obtain a coupled solution of the air bearing equation with the slider equilibrium equations. The vertex label based adaptive meshing algorithm of Cheng et al. (1999) was also implemented. The problem is initially solved with a regular quadrilateral FE mesh. The mesh adaptation (hrefinement) is based on the relative pressure gradients in the initial solution, and on the geometry of the slider. The refinement is implemented on an existing element, if preset criteria on the pressure gradient and/or slider geometry are exceeded. The method is described in detail. Examples are presented. Two types of sliders have been used, namely the 50% taper flat slider, and the negative air bearing slider.