Kyaw Sett Myo, Weidong Zhou, Kok Leong Lee, Shengkai Yu, and Wei Hua Direct Monte Carlo simulation of nanoscale mixed gas bearings Advances in Mechanical Engineering June 2015 7: 1687814015589528, first published on June 11, 2015 doi:10.1177/1687814015589528
Abstract:
The conception of sealed hard drives with helium gas mixture has been suggested over the current hard drives for achieving higher reliability and less position error recently. Therefore, it is important to understand the effects of different helium gas mixtures on the slider bearing characteristics in the head disk interface. In this paper, the helium/air and helium/argon gas mixtures are applied as the working fluids and their effects on the bearing characteristics are studied using the Direct Monte Carlo Simulation (DSMC) method. Based on DSMC simulations, the physical properties of these gas mixtures such as mean free path and dynamic viscosity are achieved and compared with those obtained from theoretical models. It is observed that both results are comparable. Using these gas mixture properties, the bearing pressure distributions are calculated under different fractions of helium with conventional molecular gas lubrication (MGL) models. The outcomes reveal that the MGL results could have relatively good agreement with those of DSMC simulations, especially when the helium percentage in the gas mixture is not too high.