קולוקוויום בחוג לגאופיזיקה: Non-equilibrium flows in porous media: Hydro-mechanical-chemical coupling, preferential pathways and hysteresis in hydrogeology
Ran Holtzman, Coventry University, UK
Multiphase and reactive flow in porous and granular materials is ubiquitous in natural and engineered processes such as diagenesis and weathering, transport of water, gases, contaminants and nutrients, carbon geosequestration, and enhanced production of energy. Common to these systems is their out-of-equilibrium behavior, including the emergence of instabilities, preferential pathways and focusing of flow and reactions, and path- and rate-dependency.
I will start with an overview my approach to expose the underlying physics of these systems. A combination of numerical simulations, controlled experiments and theoretical analysis, exemplifies how coupled mechanisms and heterogeneity at the pore-scale control the behavior at larger scales of interest.
I will then expand on a fundamental problem which has been intensively studied over the last century by geoscientists, physicists and engineers: Hysteresis, memory and energy dissipation in disordered media. I will present an ab initio model of quasistatic fluid-fluid displacements in a Hele–Shaw cell with random gap spacing. In contrast with existing phenomenological approaches, all our model parameters have a clear, identifiable physical meaning, making it accessible to rigorous experimental and analytical scrutiny. This provides a quantitative link between the microscopic capillary physics, spatially-extended collective events (Haines jumps), energy dissipation and large-scale drainage–imbibition hysteresis.
מארגני האירוע: ד"ר רועי ברקן וד"ר אסף ענבל