Lattice Boltzmann Simulation of Viscoelastic Liquid Bearing in Head-Disk Interface: A Three-Dimensional Model

Abstract

In order to keep pace with the demand of higher recording density of hard disk drive (HDD), further reduction in head-media spacing is needed. In addition to make the thinner overcoat and lubricant film, reducing the fly height is an alternative key step. Two possible candidates for next generation HDDs are quasi-contact recording and viscoelastic liquid bearing (VLB). In the first approach, the slider operates in the mixed region between sliding and flying. The modeling of the lubrication of the quasi-contact recording requires complex molecular design of both thin liquid films and air flows. In the VLB technology, an incompressible liquid film is used for the lubrication instead of conventional air bearing. Such a liquid lubrication can avoid the contact of the slider and disk, which has a very "stiff" bearing and high shock resistance. The standard mathematical modeling of lubrication for VLB has been reported in the past decades. In this paper, a novel computational tool based on lattice Boltzmann methods (LBM) is adopted to simulate the lubrication for head-disk interface using a non-Newtonian fluid model in three dimensions. LBM is a versatile numerical tool for simulating fluid flows containing complex physics phenomena. The numerous advantages including clear physical pictures, an inherently transient nature, multi-scale simulation capabilities, and fully parallel algorithms make LBM to be an attractive candidate as a next generation head-disk interface (HDI) simulation tool.