Simulation of particle rebounding from the slider air bearing surface

Abstract

An entrapped particle on the slider air bearings damages the surface of the slider or the disk. The study of particle movement on and the particle adhesion mechanism onto the slider surface is critical to reduce entrapped particle-induced damage. This paper investigates the interaction between the particles and slider surface. The particle trajectories in the far-field region are calculated using the classical Runge---Kutta method. In the near-field region, where the distance between the particle and slider surface is less than the mesh size, a new model was applied to predict the particle trajectory and whether the particle will be captured or rebound from the slider surface after the collision. A rebound model was employed to calculate the particle rebound velocity and its corresponding rebound trajectory. It was found that the particle critical velocity for rebound increases as the particle size decreases. The velocity ratio decreases as the incident velocity decreases for the same particle diameter, and it is sensitive to the particle size at a low incident velocity. For the particle collides with and rebounds from the slider surface, the negative rebound velocity makes the particles bounce a small distance away from the pad surface. The force acting on the particles also changes from negative to positive values, and they possibly undergo secondary impacts on the slider surface following air flow, which further lower the particles' velocity and increases the possibility of particles adhere to the slider surface.