This project, entitled “Chaotic Mixing in Porous Materials,” will explore the role of chaotic advection in steady flow through porous media. Previous research has suggested that chaotic mixing, for example, the exponential elongation of fluid elements by advection, strongly depends on lattice geometries, flow direction, and packing density. However, a universal understanding of chaotic advection at pore and Darcy scales is still missing.
This study will explore the emergence of chaos in discrete and continuous porous networks and will compare several parameters that characterise this process, such as the Lyapunov exponents or the decay rate of concentration variance. This will be achieved by solving numerical equations that simulate flow in different conditions, within various geometries. Interesting examples of geometries are regular lattices, random packing with polydisperse beads, and discrete fracture networks. The numerical study will involve analysing flows through various representative elementary volumes, highlighting their impact on chaotic mixing.
I have to learn how to manage the entire process of numerical research, from meshing to simulation, up to data analysis. For meshing, it is relevant how to use blockMesh and snappyHexMesh, and I am currently learning how to use GMSH. I already learned how to perform simulations using the open-source codes OpenFOAM (Finite Volume Method solver) and FenicsX (Finite Elements Method, which I am currently working on). Furthermore, I have received access to the DFN.lab code, developed by the Fractory Lab group at the University of Rennes, with which I have already started to work. This code is purposed for simulating flows in Discrete Fractured Networks. I’m actively developing codes in Python to analyse the results.
