Numerical simulation and efficient algorithm for solving gas film lubrication with consideration of height discontinuities on the air bearing surface

With the decreasing of the flying height of the air bearing slider in hard disk drives,many problems appear in the numerical solution of the gas lubrication equation,such as too long computational time or even computing divergence.In order to get the storage density of 1 Tbit/in2,the flying height of the air bearing slider will approximate 1.5 nm.In this paper,based on the linearized flow rate(LFR) model of the corrected Reynolds equation proposed by the authors,the gas lubrication equation is discretized by using finite volume method with consideration of height discontinuities of the air bearing surface.Mesh adaptive technique and Multigrid method are used in the iteration algorithm to improve the computational efficiency.A numerical method with efficient algorithm is developed to simulate pressure distribution of the slider with 0.5 nm flying height.The validity of the numerical method is verified by using an air bearing slider with complex surface shapes.Numerical results show that when the minimum flying height is relatively low,the numerical results can not be obtained without considering the height discontinuities of the slider surface.The computational efficiency of the LFR model is higher than that of FK-Boltzmann model.The computational efficiency of solving the gas lubrication equation can be reduced efficiently by using mesh adaptive technique and multigird method.