A NUMERICAL SCHEME FOR STATIC AND DYNAMIC SIMULATION OF SUBAMBIENT PRESSURE SHAPED RAIL SLIDERS

A numerical scheme based on the finite difference technique is develop ed to simulate the steady-state flying conditions and dynamic response s of subambient pressure sliders with shaped rails. In order to suppre ss numerical difficulties caused by the clearance discontinuities pres ent in the subambient pressure sliders, the control volume formulation of the linearized generalized lubrication equation is utilized. For t he shaped rail sliders, a method of averaging the mass flow across the rail boundaries is implemented. Furthermore, the power-law scheme by Patankar, is implemented in calculating the mass flows. The resulting equation is solved using the alternating direction implicit method For the simulation of steady-state flying conditions, a variable time ste p algorithm is implemented for the purpose of reaching the steady-stat e values as quickly as possible. This numerical scheme is very efficie nt in that the coarse finite difference mesh is sufficient for numeric al stability, and that the rime step changer very much improves the co nvergence rate. The static flying heights of the Transverse Pressure C ontour and the ''Guppy'' slider are calculated for different disk velo cities and slider skew angles. For the Guppy slider, the dynamic respo nses of the slider to a cosine bump and disk runout are simulated.