Derivation of the modified molecular gas lubrication equation - a porous media model

A porous media model has been developed which can be applied to ultra-thin gas film lubrication problems encountered in the analysis of a magnetic hea d slider flying over a magnetic disk coated with giant molecule liquid. In this model, the textured surface coated with giant molecule lubricant is re placed with a permeable material. The appropriate slip-flow boundary condit ions, i.e. the high-order slip-flow model, and the proper porous flow model , i.e. the Brinkman-extended Darcy model, are utilized in the gas film and porous film, respectively. The modified molecular gas lubrication (modified MGL) equation is then derived by consideration of the permeability of the running surface. Finally, the effects of porous film thickness (Delta), per meability (K) and inverse Knudsen number (D) on the. performance of the mag netic head slider are discussed.