Abstract
The main goal of this work is to develop the tools required to simulate the head-disk interface (HDI) of rigid-disk drive systems under ultra-low flying conditions. Such tools would not only provide insight into tribological test results, but would also provide design criteria for the sliders and disks. Two fundamental concepts that must be incorporated into the analysis are gaseous rarefaction and surface roughness effects, as well as the dynamic coupling that occurs between the two. When the slider and disk surfaces are smooth, the relevant length scale is the head-disk separation and rarefaction effects are determined by the air bearing's Knudsen number. Surface roughness effects are studied by incorporating statistically averaged Reynolds equations into the simulation of the HDI. In this paper, recently derived total mass flow rate coefficients are used to analyze rarefaction and roughness effects for various forms of the modified Reynolds equation.
