Modelling the removal rate of airborne dust by sprays: importance of a realistic scavenging kernel

Indoor air quality can be strongly affected by high aerosol particles concentration. When ventilation is not possible, aerosol scavenging by water sprays can be applied to protect workers. But, despite its interest for both industrial applications and occupational health, predicting realistic removal rates by means of a simple collection kernel is still a challenge. A suitable collection kernel should encompass several phenomena governing aerosol scavenging by drops such as inertial impaction, Brownian capture, electrostatic and phoretic forces (diffusiophoresis, thermophoresis), all affected by the flow regime around the drop as well as heat and mass transfers through evaporation. We propose to set up a new correlation for a global scavenging kernel upgrading its prediction capabilities both concerning accuracy and range of use. It is based on published reference data and, when needed, on new data obtained through CFD simulations of particle-laden flows around and inside a drop at moderate Reynolds number.