Two and three dimensional simulation of flow and particle transport in porous media

The simulation of fluid flow and particle transport in porous media finds important
appli cations in many different fields, ranging from environmental and petroleum engineering to filtration and industrial chromatography. Different types of approaches exist and are generally classified by the length- and time-scales involved. Real industrial problems require the treatment of the porous medium as a continuum via the definition of porosity and permeability.
However, these parameters are very difficult to be determined and therefore a strategy to identify
them from pore-scale simulation is investigated here. When particles are characterized by nanoscopic size we are in presence of a so-called colloidal suspensions and also micro-scale forces and phenomena such as particle aggregation and deposition play an important role in determining the overall dispersivity of particles. Two and three dimensional geometries characterized by different degrees of complexity are created and studied using computational fluid dynamics codes. First the flow and particle transport around spherical grains arranged in a regular lattice is investigated. Then the analysis is extended to irregularly arranged spherical grains (of equal and different size) mimicking a realistic porous medium. Eventually geometries constituted by grains of realistic shapes are also considered. The accurate simulation of these systems require the solution of a number of mathematical and numerical challenges, related to multi-scale modelling, computational geometry, mesh processing and discretization techniques. Particular attention is devoted to the choice of adequate mathematical models and numerical strategies for the simulation of dispersed multiphase flows and to the assessment of
two meshing strategies: highly irregular body-fitted meshes versus regular cartesian-based
immersed-boundary approach.