Deposition characteristics of ultrafine particles of different shapes in an inertial impactor: CFD-DEM simulations and experiments

In this study, the deposition characteristics of non-spherical ultrafine particles in an inertial impactor were analyzed. Firstly, numerical simulations were conducted using a model developed via computational fluid dynamics and the discrete element method (CFD-DEM). The numerical results suggested that the particle deposition characteristics were influenced by the drag force, adhesion force, and particle inertia. Moreover, the collection efficiencies of spherical, triangular, and cylindrical particles in the impactor were examined, and cylindrical particles with a large aspect ratio exhibited the lowest collection efficiency. Secondly, experiments were conducted using a particle dispersion system, particle collection system, and particle size distribution measurement system, and the particle size spectrum was measured using a scanning mobility particle sizer (SMPS). The experimental results demonstrated that the collection efficiency of non-spherical particles was lower than that of spherical particles for the same initial concentration in the impactor, which was in good agreement with the simulation results.