An Experimental Study of Reduction for Aerodynamic Excitation to Head-Arm of HDD

Abstract

This paper deals with reduction methods of aerodynamic excitation for a head-arm of HDD experimentally. Two types of measurement were conducted ; flow visualization around enlarged head-arm models by using a smoke tunnel, and flow field between co-rotating disks of HDD. On the flow visualization, we put a focus on separation of the flow. It is found that width of the separation can be reduced by optimizing design of the hole in the head-arm, chamfering front edge of the head-arm, and so. On the flow field, we examined flow vectors, fluctuation of the flow, frequency characteristics, influence by existence of the head-arm, and so. No factors especially exciting the head-arm were recognized. Therefore, aerodynamic excitation force is considered to be mainly due to the turbulence caused by separation, flow instability of wake, and so.