Active airborne noise control of hard disk drive

With the increase of rotation speed of hard disk drives, vibration and acoustics specifications are often required by customers. The airborne (windage) noise, which is the dominant noise source for fluid dynamic bearing and high RPM applications, is transmitted through the cover. Thus, the vibration and acoustics performance of HDD are closely related to the properties of HDD covers. In this paper, in order to control the noise of the cover, collocated piezoelectric actuators and sensors are adopted and mounted on the cover. Two dimensional dynamic finite element formulations coupling with the effect of pressure in the cavity are derived using the first order shear deformation theory for the disk cover in addition to the mechanical-electro coupled variation equation. Numerical results show that airborne noise of the cover can be reduced through active control of the actuator.