Averaged Reynolds Equation Based on the Homogenization Theory for Gas Film Lubrication in the Head/Disk Interface

In order to improve the magnetic recording density of hard disk drives, discrete track disks and/or bit patterned disks are being considered. The gas film lubrication characteristics of a disk with microscale geometric surface features are different from those of traditional “smooth” disks. In this paper, an averaged Reynolds equation suitable for the analysis of gas film lubrication with discrete track recording (DTR) disks is derived based on the homogenization theory and a simplified model of the Reynolds equation with linearized flow rate (LFR). The averaged Reynolds equation and the LFR model are solved simultaneously using the finite volume method. Numerical results show that the pressure solution of the averaged Reynolds equation agrees well with the LFR model for DTR disks. The exact pressure values fluctuate in the neighborhood of those of the averaged pressure distribution curve. The pressure distributions of a complex slider for different groove depths are presented to investigate the effects of groove depth on pressure profiles. The proposed approach is shown to have a high computational efficiency.