Numerical analysis of flying-height fluctuation and positioning error of magnetic head due to flow induced by disk rotation

A numerical analysis method is proposed for the evaluation of flying-height fluctuation and positioning error necessary for designing high-recording-density and high-disk-speed disk drives. Flying-height fluctuation and positioning error of a head are calculated by applying flow force fluctuation, which is calculated using a finite-element-method program for turbulent flow around the suspension of the head to a vibration analysis program for the head and its suspension. In the flow analysis, a pseudo-three-dimensional flow model based on experimental observation is used. In this model, three kinds of vortex street cells are distributed along the span of the suspension. The calculated fluctuations of a head between two corotating 356-mm-diameter disks at 3600 rpm agree with those measured in an actual 356-mm disk drive.<
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