AVERAGED REYNOLDS EQUATION AND ITS EFFICIENT NUMERICAL SOLUTION IN THE HEAD/DISK INTERFACE

In an operating hard disk drive the slider is flying over the high speed disk, a few nanometers of gas lubrication film is developed in the head/disk interface, and the gas film lubrication equation is modified by considering the gas rarefied effect. In order to improve the magnetic recording density of hard disk drives, a discrete track recording (DTR) disks are being considered to replace the traditional smooth disk. Owing to the track and grooves on the surface of the DTR disk, a lot of numerical grids are required to discern the surface geometry of the DTR disk, resulting in a low computational efficiency of solving the modified Reynolds equation. In this study, an averaged Reynolds equation suitable for the analysis of gas film lubrication with discrete track recording (DTR) disks was derived based on the homogenization theory and a simplified model of the Reynolds equation with a linearized flow rate (LFR). The averaged Reynolds equation and the LFR model were solved simultaneously using the finite volume method. With comparing to the modified Reynolds equation, a few discreted numerical grids were required to solve the averaged Reynolds equation, thereby saving a large amount of computational time. The largest relative errors of the pressure distribution, pressure center and bearing capacity of the modified Reynolds equation and the averaged Reynolds equation were less than 3.5%.