Evaluation of a Moments-Based Formulation for the Transport and Deposition of Small Inertia Aerosols

Abstract

This paper introduces and evaluates a formulation for the modeling of transport and wall deposition of aerosols, written in terms of moments of the particle size distribution (PSD). This formulation allows coupling the moment methods with computational fluid dynamics (CFD) to track the space and time evolution of the PSD of an aerosol undergoing transport, deposition and coagulation. It consists in applying the quadrature method of moments (QMOM) to the diffusion-inertia model of Zaichik et al. [6], associated with the dynamic boundary layer (DBL) approach of Simonin [8] for wall deposition. After presenting the QMOM formulation of the transport equation and of the DBL wall function, the paper presents several test cases in which the method is compared to existing experimental and numerical results. It is shown that the moment formulation of the model does not introduce particular bias compared to its concentration-based formulation. This extension of the diffusion-inertia/DBL approach to the QMOM method hence allows modeling with a good numerical efficiency and at building scale the dynamics of aerosols undergoing transport and modification of their PSD through coagulation and deposition.