Influence of Particle Properties on Friction Reduction of Particle Mass by Ultrasonic

Ultrasonic has been applied to a particle mass and the friction reduction on a plate has been investigated. As a result, it has been shown that the friction between particles and a plate is reduced by the ultrasonic similar to a cube. Although the extent of reduction is little affected by the particle diameter and shape, a particle mass with a larger bulk density required a larger ultrasonic power to reduce the frictional resistance. Then the relation between bulk density and amplitude of plate vibration which is required to float particles on the plate was obtained by using equations derived for cubic particles. Furthermore, the influence of sound transmission coefficient through a particle on friction reduction has been confirmed by analyzing the particle motion. Particles with a smaller transmission coefficient require a larger ultrasonic power because they absorb less energy from the ultrasonic waves.