Mechanical and Civil Engineering Seminar
Flow and transport through porous media is ubiquitous in nature. They are key processes behind subsurface resources such as oil and gas, geothermal energy, and groundwater. They also mediate corrosion and ageing of porous engineering materials as well as geohazards such as landslides, volcanic eruptions and earthquakes.
Central to many of these processes is the strong coupling between porous media flows and phase transitions—the creation or destruction of fluid or solid driven by thermodynamics. Multiphase flow with phase transitions often leads to dynamic systems that are far from thermodynamic equilibrium. In this talk, I will describe two examples of nonequilibrium phenomena, and new continuum mathematical descriptions to model them. First, I will discuss the role of mineral-dissolution reactions during geologic sequestration of carbon dioxide. Then I will address the modeling of methane clathrate (gas hydrate) in multiphase environments using phase-field methods. Motivated by field and laboratory observations, I will describe how the spontaneous formation of a solid hydrate crust on a moving gas-liquid interface gives rise to a new type of flow instability we term crustal fingering. I will further show that this solid-modulated gas percolation mechanism is crucial to our understanding of methane venting in the world's oceans, gas hydrate dissociation as a trigger to landslides, and energy extraction from gas hydrate deposits.
Finally, I will discuss how this research on fluid-solid coupling in porous media can stimulate new questions at the interface of engineering, geosciences and material sciences.