Abstract: Hard disk drives (HDDs) are now the most important means of information storage. They continue to be made smaller in size, higher in capacity, and lower in flying height. Generalized non-dimensional Reynolds equation including pressure flow factor and shear flow factor based on a linearized flow rate (LFR) model is solved by using a meshless method called least square finite difference (LSFD) method. Effects of the surface roughness on static characteristics of the air bearing film in HDDs with ultra-low flying heights (1-2 nm) are investigated. Numerical results show that effects of the surface roughness on the pressure distributions and the load carrying capacity are great, while effects of the surface roughness on the pressure center are small. Lower flying height and/or greater value of surface roughness leading higher influence on the pressure distribution and the load carrying capacity. With the same value of surface roughness, the rough head with transverse roughness leads to the maximum pressure distribution and load carrying capacity of the system. The surface roughness does not have much influence on the pressure center, which indicates that the head/slider has good flying stability. Moreover, based on LFR model to investigate the effects of the surface roughness on static characteristics of air bearing films in HDDs, not only good accuracy in numerical results can be obtained but also very high computational efficiency can be achieved.

Key words: Gas bearings flim, Hard disk storage, Meshless method, Reynolds equation, Surface roughness