Simulation using the limiting velocity approach of acoustic streaming establishment and aerosol particle focusing in complex-shaped acoustofluidic devices

In this study, we investigated the formation of acoustic fields and their influence on the particle distribution in complex-shaped acoustofluidic devices by considering the quadrupole hyperbolic resonator as a representative benchmark problem using an approach that can be applied to other resonator geometries. The Navier-Stokes equations for gases were solved twice, with different boundary conditions each time. An approach based on the limiting velocity method was used to simulate the formation of acoustic streaming and particle focusing. The effects of phase shifts in the boundary oscillations on the acoustic streaming and particle focusing patterns in the quadrupole hyperbolic resonator were investigated. The transient formation processes of Rayleigh vortices and the particle distributions were simulated at the resonant mode. Zones with drastically increased particle concentrations (acoustic traps) were identified. The results showed that the resonant frequency, locations of acoustic traps, and their form were highly dependent on the phase shifts of the boundary oscillations. (c) 2020 Elsevier Inc. All rights reserved.