Influence of Acoustic Pressure and Flexural Vibration on Friction Reduction Effect by Ultrasonic

The influence of acoustic pressure and flexural vibration on friction reduction effect by ultrasonic has been investigated in this study. Then the relationship between friction reduction of particles by each effect and the particle density has been shown by using of ultrasonic. Additionally, the maximum of particle density which could receive the friction reduction effect by the acoustic pressure has been expressed. In short, when the particle density was large, the influence of friction reduction effect by the acoustic pressure decreased and the influence of friction reduction effect by the flexural vibration grew. In this study, two plates were set parallel to each other. The dried particles were scattered on the lower plate, and the ultrasonic was applied. Then, the entire equipment setup was tilted slowly until the scattered particles began to move, and the friction coefficient was measured. Then, influence of acoustic pressure and flexural vibration were evaluated. In order to evaluate the reduction effect by acoustic pressure and flexural vibration, firstly, the distribution of acoustic pressure between reflection plate and the vibration plate have been measured. As a result, it was clarified that acoustic pressure distribution became the almost same whether ultrasonic was applied for the upper or lower plate, and the reflection plate vibrated little. Therefore it was possible to divide the influence of acoustic pressure and flexural vibration on the friction reduction.