Numerical study of particle separation with standing surface acoustic waves (SSAW)

The particle manipulation technology based on standing surface acoustic waves (SSAW) has been widely used with high efficiency and low consumption. However, it is difficult to study particle motion at the microscopic scale with experimental methods and conventional continuous methods. In this paper, computational fluid dynamics (CFD) and the discrete element method (DEM) are used to describe the fluid-particle flow, and the effect of the acoustic field is calculated according to Gorkov's theory. The established model is validated by the particle separation in micro-channel under SSAWs as the simulation results are in good agreement with experiments in publication. The consistency between the numerical simulation results and the experimental results in separation time and separation distance confirms the merits of model. The particle motion, space distribution, velocity field, force analysis and particle collision have been conducted thoroughly to reveal the mechanism of the separation.