Simulation of particle trajectory of 1.8-in Hard Disk Drive

Abstract

A simulation of the particle trajectory of a 1.8-in hard disk drive is constructed based on precise actual dimensions of a current 1.8-in hard disk drive in the market with 3600 rpm rotation speed. The RNG k-epsilon model is used to investigate the air flow in the hard disk drive. The general particle trajectory has been calculated using the discreet random walk model (stochastic tracking). In the model, 0.5 μ-in particles have been released from the top of the Head Stack Assembly (HSA) bearing, the particles are brought inward to the centre of the rotating disk then they are thrown outward toward the disk edge closer to the disk surface. The particles barely move to the coil side of the HSA because the air velocity is lower than inside the rotating disk area. Also the whirl of the air at the ramp load area creates a spiral like trajectory.