Simplified precise model of Reynolds equation for simulating ultra-thin gas film lubrication in hard disk drives

In order to increase the recording density of magnetic disk drives, the spacing between the flying head and the rotating disk must be as small as possible. When the spacing between the flying head and the rotating disk approaches the mean-free path of the gas, rarefaction effects must be taken into account. The authors propose a simplified precise second order (PSO) model that implements a Poiseuille flow rate database to simulate ultra-thin gas film lubrication. The PSO model is evaluated using the finite volume method. Numerical results obtained using the PSO model are presented and compared with the results from simulations that implement four formerly and currently employed lubrication models including the first-order, the second-order, the 1.5-order, and the widely used FK (Fukui and Kaneko) models. The PSO model’s key advantages are validated in three aspects: mathematical formulation, simulation accuracy, and computational efficiency.