Establishing a Quantitative Functional Relationship between Capillary Pressure Saturation and Interfacial Area

Abstract

SUIWMARY OF OBJECTIVESWe propose to continue our collaborative research focused on advanced technologies for subsurface contamination problems. Our approach combines new multi-phase flow theory, novel laboratory experiments, and non-traditional computational simulators to investigate practical approaches to include interfacial areas in descriptions of subsurface contaminant transport and remediation. Because all inter-phase mass transfer occurs at fluid-fluid interfaces, and it is this inter-phase mass transfer that leads to the difficult, long-term ground-water contamination problems, it is critical to include interfacial behavior in the problem description. This is currently lacking in all standard models of complex ground-water contamination problems. In our earlier project, we developed tools appropriate for inclusion of interfacial areas under equilibrium conditions. These include advanced laboratory techniques and targeted computational experiments that validated certain key theoretical conjectures. However, it has become clear that to include interfacial behavior fully into a description of the multi-phase flow and contamination problems, the Molly dynamic case must be considered. Therefore, we need to develop both experimental and computational tools that can capture the dynamic nature of interfacial movements. Development and application of such tools will allow the theory to be evaluated, and will lead to significant improvements in our understanding of complex subsurface contamination problems, thereby allowing us to develop and evaluate improved remediation technologies.We propose to combine theoretical, experimental, and computational research efforts to achieve the following goals: 0 Develop new experimental techniques to measure interface dynamics, under realistic conditions of movement in porous media. 0Develop new computational algorithms that properly incorporate interface dynamics, and that include wedges and films of wetting fluid. .Test existing theory and develop new theory, in conjunction with the experiments and the computations, to provide practical definitions to fundamental terms like dynamic capillary pressure and average interfacial velocity. 0Synthesize the results of the experimental, computational, and theoretical investigations to develop a new model for multi-phase flow and contaminant transport in contaminated soils and ground waters. Compare this new approach to standard methods and evaluate the potential improvements in terms of soil characterization and remediation evaluation.The results of this research will provide guidance regarding fundamental questions of remediation efficacy. We will examine how interfacial areas need to be characterized, and under what conditions their dynamics need to be included in practical analyses of subsurface contamination problems, Given that these interfaces are the source of contaminants to the aqueous phase, it is important that we continue our ongoing investigations of the role of these interfaces in contamination problems, the influence o...