Novel approach to model microstructure of dust-deposits comprised of polydisperse particles of arbitrary shapes

Abstract

Morphology of airborne particles plays a key role in the growth rate of dust-cake formed on an exposed solid surface, or on the face of an air filter. The work presented in this paper reports on a fast and flexible algorithm to simulate the microstructure of dust-cakes resulting from deposition of non-inertial airborne particles of arbitrary shapes. Our approach is based on representing a non-spherical particle as an assembly of spherical beads connected to one another via springs and dampers. This mass-spring-damper (MSD) model allows one to study the effects of particle shape, particle size, and particle rigidity on the thickness and porosity of the dust-cakes that result from deposition of such aerosol particles in different applications. In aerosol filtration applications for instance, the ability to predict the thickness and porosity of a dust-cake comprised of non-spherical particles is needed before one can predict the pressure drop or collection efficiency of a dust-loaded filter. For demonstration purposes in this paper, dust-cakes comprised of particles with cubical and spherocylindrical shapes as well as Jacks-toy and Plus-sign shapes are simulated and discussed.