Microscale Simulation of Two-Fluid Flow in Porous Media for Macroscale Model Evaluation, Validation, and Parameter Estimation

Abstract:

Accurate simulation of physical media and multiphase flow phenomena is necessary to compute microscale quantities for the evaluation, validation, and parameter estimation of macroscale models. We present a new lattice-Boltzmann model that significantly improves the ability to measure quantities important in the closure of our two-fluid-flow model. Components of the model include ray-tracing for the solid phase, a linear interpolation bounce-back method, second-order off-lattice color gradient method, and improved mass conservation using a finite volume method. Analysis of both phase and interfacial quantities is done strictly using triangular meshes which has been shown to be superior to interpolation and coarse lattice-based methods. These new advancements incur additional computational cost and algorithmic complexity, ,which coarse but fast methods avoid. High resolution simulations of idealized media are performed to validate microscale and macroscale evolution equations and to determine a Representative Elementary Volume for two-fluid flow through idealized porous media.