Dynamic behavior of air bearing slider in air-helium gas mixtures

To reduce flutter and windage loss, helium has recently been used in high performance disk drives [1]. Several authors have studied the effect of helium on the stability of the head/disk interface, indicating that helium is beneficial for reducing head/disk dynamics and for increasing the track density in hard disk drives [2-5]. This paper studies the dynamics of the head/disk interface in helium and helium/air mixture. The Reynolds equation is used to simulate the flying characteristics of the head/disk interface to shock loading. Rarefaction and Van der Waal's effects are considered. Real time numerical simulations and power spectrum analysis are performed to analyze the frequency characteristics as a function of disk speed, flying height, and impulsive force.