Research Theme 5: Thermodynamic Driving Forces

Objective:

Develop a non-equilibrium thermodynamic description of two-phase flow that includes gravitational, osmotic, chemical and thermal driving forces, as well as capillary forces and disjoining pressures, with the aim to construct a consistent and general description of two-phase flow that accounts for the relevant driving forces.

Transport of particles across a non-wetting pore due to a temperature difference across the pore. The particle stays in the gas phase. Picture courtesy: Olav Galteland.

Description:
We are working to extend the description of flow in porous media beyond the Darcy or Washburn regimes.  Flow can also occur in two-phase systems due to temperature gradients.  For instance, the transport of water vapor across a hydrophobic pore, enables us to use low temperature waste heat to clean contaminated water solutions. The use of thermal and other driving forces for porous media transport is interesting for instance in the modelling of frost heave in geophysical contexts. Electroacoustic signals can be used to characterize the state of clay and consolidated muds. For this, the interplay between theory and experiments is essential. The second law of thermodynamics governs the laws of transport, but has mostly been formulated for bulk systems. Our main challenge lies in incorporating the structure of the porous material into the nonequilibrium thermodynamic description in order to describe its interplay with the multiphase flow through the pores.

Investigators

Principal Investigator for Research Theme 5: 
Professor Øivind Wilhelmsen

Partners:
Profs. Dick Bedeaux, Eirik Grude Flekkøy, Bjørn Jamtveit, Bjørn Hafskjold, Miguel Rubi, Signe Kjelstrup, Claire Chassagne, Natalya Kizilova, Joachim Gross.

Researcher:
Seyed Ali Ghoreishian Amiri, Morten Hammer, Ailo Aasen.

PhD-candidates:
Olav Galteland, Michael Rauter, Vilde Bråten, Vegard Jervell