MESA+ University of Twente
Multiscale Modeling and Simulation

Aerosols in filters

Particle-laden flow in porous media

Organization:
Funded by: Philip Morris Products S.A.
PhD: Lilya Ghazaryan
Supervisor: Bernard Geurts / Steffen Stolz
Collaboration: Philip Morris International Research & Development

Description:
Understanding the behavior of aerosol droplets in porous media is of importance for many applications. For instance, in order to quantify filtration efficiency of filters, it is essential to know the dynamics of the droplets in such environments. By performing mathematical modeling and numerical simulations we aim to have a detailed description of the processes that droplets undergo during their traversal through the porous material (e.g., deposition on the surface of the solid and thermal processes, such as evaporation and condensation).

The motion of a droplet is directly, or indirectly, influenced by a number of factors. Properties of a droplet, such as its shape, mass and chemical composition, are essential parameters, which influence its dynamics. During the droplet's motion through the porous medium these parameters can change due to the varying conditions encountered by the droplets on their path through the flow field. These variations in local properties can be caused by variations in the inner structure of the porous material. Basically, it is a very complex system with three major components: fluid, the droplets that are embedded in the fluid and the porous material through which the fluid flows. There are a number of approaches for modeling each of these components.

In this research project we employ an Euler-Lagrange approach for the fluid-particle two-phase flow. The fluid phase is solved using the incompressible Navier-Stokes equations and the porous medium is incorporated using the immersed boundary method. The motion of small spherical particles in a fluid flow is approximated by including Stokes drag and a random Brownian forcing. Dependency of filtration characteristics on several physical parameters, such as porosity, gas flow rate, temperature of the gas, particle size, etc., is quantified.

Publications:

E-prints overview

Papers in preparation:

•  Ghazaryan, L. and Geurts, B.J.  and Lopez Penha, D.J. and Stolz, S. and Kuczaj A., 
    “No-slip consistent immersed boundary particle tracking to simulate impaction filtration in porous media”(to be submitted to International Journal of Numerical Methods in Fluids).

Posters:

•L. Ghazaryan , D.J. Lopez Penha, B.J. Geurts, S. Stolz,  A.Kuczaj , 
”Particle tracking in  porous media to estimate aerosol filtration”, WSC2011 Woudschoten conference, 5-7 October 2011, Zeist, Netherlands.

•L. Ghazaryan, D.J. Lopez-Penha, B.J. Geurts, S. Stolz, C. Winkelmann, 
“Simulation of impaction filtration of aerosol droplets in  porous media”,  ECCOMAS; Portugal 2010