Vibration-Induced Attraction of a Particle Towards a Wall in Microgravity—The Mechanism of Attraction Force

Abstract

The effects of small vibrations on a particle oscillating near a solid wall in a fluid cell, relevant to material processing such as crystal growth in space, have been investigated by three dimensional direct numerical simulations. Simulations have been conducted for a solid spherical particle suspended in a fluid cell filled with a fluid of 1 cSt viscosity, vibrating sinusoidally in a horizontal direction. The simulations revealed the existence of a vibration-induced force attracting the particle towards the nearest cell wall which varied with the cell vibration frequency. The mechanism for this attraction force as well as an example showing the effects of this force on the particle are presented in this paper. The predicted flow patterns around the particle unveiled an accelerated flow in the gap between the particle and the nearest wall as well as a pressure decrease in accordance with Bernoulli’s principle, which would result in the attraction force.