MATHEMATICAL-MODELING OF LUBRICATION FOR THE HEAD-DISK INTERFACE USING INCOMPRESSIBLE FLUIDS

In order to keep pace with the demand for higher storage densities in magnetic recording disk drives, new technology must be developed to re duce the tribological problems associated with ultralow flying. Non-Ne wtonian liquid bearings may become a feasible alternative to slider mi niaturization due to the decrease in slider-disk contacts. Issues pert aining to modeling the head-disk interface are presented, and non-Newt onian effects are described. Generalized Newtonian fluid models descri be the dependence of the apparent viscosity on the shear rate for bulk fluids, but the extremely high shear rate and the confined geometry a t ultralow flying heights complicate conventional non-Newtonian rheolo gical models. Equations are developed for generalized Newtonian fluids which can determine the flying characteristics of recording sliders i n viscoelastic drives. Order-of-magnitude analyses are performed in or der to determine the effect of drive parameters and fluid properties o n the load bearing capacity of the slider and power consumption due to frictional forces. The results obtained are new and may become import ant in providing design criteria for VISqUS drives or to related desig n engineers.