Comparative DEM-CFD study of binary interaction and acoustic agglomeration of aerosol microparticles at low frequencies

Abstract

The paper concerns the problem of acoustic agglomeration due to the acoustic wake in diluted aerosols and addresses the development of the time-accurate discrete element method (DEM) simulation technique. The case of weak entrainment of heavier mono-sized microparticles at low-frequency sound waves is considered. The agglomerative motion of two identical micron-sized spherical particles is simulated numerically, and contribution of the particles boundary layer in transition from the diluted to the dense phase is investigated. A comparative study of the DEM approach against more accurate computational fluid dynamics (CFD) computations is performed. The 3D incompressible viscous flow of aerosol medium described by Navier–Stokes equations is considered regarding the fine scale of particles. The numerical results regarding the agglomeration rate, drag coefficient, and perturbation velocities are discussed. Moreover, the correction to the fluid–particle interaction force is proposed to increase the accuracy of the DEM model.