Numerical study of aerosol particle deposition in simple and converging–diverging micro-channels with a slip boundary condition at the wall

Abstract

The design of micro-devices involving aerosol transport requires the study of the deposition of aerosols in micro-channels. In this study, the slip and no-slip boundary conditions for the gas flow regime were applied to the Navier–Stokes equations to obtain the particle deposition in simple and converging–diverging micro-channels. The equation of particle motion included inertial, viscous, Brownian, and gravity terms. It was found that the ratio of gravity to inertial effects controls the deposition of particles with diameters of 0.1–1μm, and the ratio of diffusion to inertial effects controls the deposition of particles with diameters of 0.01–0.001μm. Comparison between the no-slip and slip flow regimes showed that the deposition of 0.1- to 1-μm-diameter particles was less and the deposition of 0.01- to 0.001-μm-diameter particles was greater for the slip flow regime. There was no significant difference between slip and no-slip flow regimes for the deposition of 0.01- to 0.1-μm-diameter particles. Finally, it was shown that the stagnated gas in the corners of the converging–diverging micro-channel produced similar gas velocity profiles under the slip and no-slip flow regimes.