Effects of Temperature on Particle Trajectory Inside the Helium-Filled Hard Disk Drive

The presence of particles, which can intrude into the air bearing, is one of the most common factors in the failure of hard disk drives (HDDs). Previous works investigated the particle trajectory inside air-filled drives without considering the temperature effects on the distribution of particles. Actually, for the submicron particle, particle trajectory and trapping status are affected by the temperature gradient since the thermophoretic force cannot be ignored. In this paper, considering the major heat generation components such as spindle motor and voice coil motor (VCM), the trajectories and trapping status for Al₂O₃ particles with diameter of 0.3 μm inside a 2.5 inch helium-filled drive are simulated by the commercial computational fluid dynamics solver FLUENT with user-defined functions (UDFs). The trapping criterion for Al₂O₃ particles are used as the boundary conditions for the different colliding surfaces.