The reduction of windage, flow induced vibrations of head sliders in the off track direction, is an important step towards increasing the track density of hard disk drives. We measured windage of several types of head gimbal assemblies in the various conditions such as disk rotational speed and atmosphere temperature by using laser-doppler-vibrometers, particle-image-velocimetry, laser-doppler-anemometers, and custom-made spin-stands. We discovered windage can be reduced by decoupling the vibration modes and increasing the resonance frequencies of head gimbal assemblies.
