title: Microscale simulation of particle deposition in porous media.
abstract: In this work several geometries, each representing a different porous medium, are considered to perform detailed computational fluid dynamics simulation for fluid flow, particle transport and deposition. Only Brownian motions and steric interception are accounted for as deposition mechanisms. Firstly pressure drop in each porous medium is analyzed in order to determine an effective grain size, by fitting the results with the Ergun law. Then grid independence is assessed. Lastly, particle transport in the system is investigated via Eulerian steady-state simulations, where particle concentration is solved for, not following explicitly particles' trajectories, but solving the corresponding advection-diffusion equation. An assumption was made in considering favorable collector-particle interactions, resulting in a "perfect sink" boundary condition for the collectors. The gathered simulation data are used to calculate the deposition efficiency due to Brownian motions and steric interception. The original Levich law for one simple circular collector is verified; subsequently porous media constituted by a packing of collectors are scrutinized. Results show that the interactions between the different collectors result in behaviors which are not in line with the theory developed by Happel and co-workers, highlighting a different dependency of the deposition efficiency on the dimensionless groups involved in the relevant correlations.
authors.affiliation: DISAT - Dipartimento Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Boccardo
authors.affiliation: DISAT - Dipartimento Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: daniele.marchisio@polito.it.
authors.forename: Daniele L
authors.initials: DL
authors.lastname: Marchisio
authors.affiliation: DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
authors.forename: Rajandrea
authors.initials: R
authors.lastname: Sethi
keywords: Brownian deposition; CFD; Nanoparticle deposition; Pore-scale simulation; Porous media; Steric interception