Multiphase flow is simultaneous flow of (a) materials with different states or phases (i.e. gas, liquid or solid), or (b) materials with different chemical properties but in the same state or phase (i.e. liquid-liquid systems such as oil droplets in water). Multiphase flow in porous media is encountered in a number of natural and industrial applications. The current models of two-phase flow are based on the assumption of continuity of phases, but it gets more complex when discontinuous phases form during the evolution of the flow. Some examples: in air sparging of polluted ground water, upward movement of air is mainly in the form of discontinuous bubbles; in the course of potential melting of gas hydrates, gas bubbles will exist as a discontinuous phase; the remediation of polluted soil from Non-Aqueous Phase Liquids (e.g. gasoline, petroleum) relies on the mobilisation of stagnant NAPL ganglia; etc.
Ioannis’s study combines novel and traditional methods to perform multiphase flow experiments, in order to acquire pore scale information that were not available in literature, so as to get a better understanding of the flow of discontinuous phases. His results and recommendations contribute to the (further) development and testing of a theory for the macro-scale description of discontinuous two-phase flow involving bubbles and/or droplets.