| Popis: |
Non-dilute flow and transport in porous media plays an important role in many natural and engineered systems, however a mature understanding is lacking. As environmental conditions change and water resources become scarcer, the need for a more complete understanding of non-dilute flow and transport will be necessary to address future challenges, for example, assessing impacts of climate change on fresh water supplies and examining mitigation strategies. The thermodynamically constrained averaging theory (TCAT) is an approach for developing mathematical models that ties together conservation and thermodynamic laws and connects all spatial scales. This approach is used to develop a new macroscale model for non-dilute flow and transport in porous media. This model is found to more accurately describe a set of non-dilute laboratory displacement experiments as compared to existing models. Through the development of the model, an entropy production rate is derived and a new numerical method is formulated that utilizes the entropy production rate to improve computational efficiency. The general framework of this new approach can be applied to other models where the entropy production rate is known. To further improve macroscale models and our understanding of non-dilute behavior, microscale simulations are performed. As TCAT relates all spatial scales, the microscale simulations are averaged to gain insight on macroscale behavior. The importance that density, viscosity, and activity have on macroscale transport is assessed and microscale velocity distributions are analyzed to explain gravity stabilization and macroscale transport behavior. |
