High-Concentration-Gradient Dispersion in Porous Media: Experiments, Analysis and211 Approximations. Modelling, Analysis and Simulation

摘要

A recently developed theory suggests a nonlinear relation between concentration211u001egradient and dispersive mass flux, introducing a new parameter in addition to the 211u001elongitudinal and transversal dispersivities. Once a unique set of relevant 211u001eparameters has been determined (experimentally), the nonlinear theory provides 211u001esatisfactory results, matching experimental data of column tests, over a wide 211u001erange of density differences between resident and invading fluids. The equations 211u001edescribing high concentration brine transport are a fluid mass balance, a salt 211u001emass balance in combination with a nonlinear dispersive mass flux equation, 211u001eDarcy's law and an equation of state. We study the resulting set of nonlinear 211u001epartial differential equations and derive explicit (exact) and semi-explicit 211u001esolutions, under various assumptions. A comparison is made between mathematical 211u001esolutions, numerical solutions and experiments in a wide range of density 211u001edifferences, given a unique set of experimentally determined parameters.