The thesis is dedicated to the quantitative analysis of the fluid flow and transport processes (advection, diffusion, and their combination — hydrodynamic dispersion) in void space of dense random sphere packings using computer simulations. In other words, the thesis description can be formulated as “pore-scale simulation of advection–diffusion transport in porous media”. A typical workflow (which is described, discussed, and validated in Chapter 1) forming the simulation procedure included computer generation of a random packing of solid impermeable spheres, simulation of low Reynolds number flow in the packing void space (i.e., flow between/around spheres fixed in space), and simulation of advection–diffusion motion of infinitely small non-reacting particles (tracers) in the packing void space using the three-dimensional flow field from the previous step. “Advection–diffusion” denotes displacement of each tracer occurred due to flow of a fluid (advection) and random motion (diffusion).
Different geometrical parameters of sphere packings (such as void space fraction, “randomness” of spheres arrangement, cross section of the hard-wall container containing the packing) were varied and their influence on the aforementioned transport processes was studied in detail.
Computer simulations were performed on high-performance computing systems (supercomputers) utilizing up to hundreds of thousands CPU cores (details can be found in the technical report).