Mechanical and Civil Engineering Seminar
Mechanical and Civil Engineering Seminar Series
Title: Statistical Mechanics of Immiscible Two-Phase Flow in Porous Media
The central problem in the physics of multiphase flow in porous media is to find a proper description of the flow at scales large enough so that the medium may be regarded as a continuum: the scale-up problem. It is the same kind of problem as finding a proper description of fluids at the continuum level when we know that they consist of molecules; a problem that in this case was solved almost two hundred years ago with the introduction of the Navier-Stokes equation. So far, the only workable approach to the multiphase flow scale-up problem has been a set of phenomenological equations that have obvious weaknesses. Attempts at going beyond this relative permeability theory have so far never led to practical applications due to exploding complexity.
Edwin T. Jaynes proposed in the fifties a generalization of statistical mechanics to non-thermal systems based on the information theoretical entropy of Shannon. We have used this approach to construct a description of immiscible two-phase flow in porous media at the continuum scales, which is directly related to the physics at the pore scale, and with a level of complexity that is manageable. The approach leads to a thermodynamics-like formalism at the continuum scale with all the relations between variables that "normal" thermodynamics has to offer.
Hansen did his undergraduate work at the University of Oslo and a PhD in theoretical physics at Cornell University. He then held postdoc positions at the Ecole Normale Superieure in Paris and the University of Cologne in Germany. In 1994 Hansen became professor of theoretical physics at the Norwegian University of Science and Technology in Trondheim, a position he still holds. He has an honorary doctorate from the University of Rennes in France, where he also holds a habilitation degree. He is the director of the Center of Excellence PoreLab since its opening in 2017. He is also the chief editor of Frontiers in Physics. His main research is on the physics of flow in porous media.
NOTE: At this time, in-person Mechanical and Civil Engineering Lectures are open to all Caltech students/staff/faculty/visitors.