Electrochemical Engine Center

ECEC Fuel Cell Research: Multiphase Flow, Heat and Mass Transfer in Porous Media

Investigators: C. Y. Wang, Oliver T. Easterday, and Alan Shoda

Sponsor: Pennsylvania State University

Problems involving multiphase flow, multicomponent transport and heat transfer in porous media arise in a number of scientific and engineering disciplines. Important technological areas include oil reservoir engineering, groundwater contamination and remediation, heat pipe technologies, drying processes, particulate materials processing, trickle bed reactors, and geothermal reservoirs. For many decades, the traditional multiphase flow model based on the generalized Darcy's law has been used. Unfortunately, this model is cumbersome and computationally demanding when applied to predicting multiphase flow and transport; obtaining a multi-dimensional solution using this model presents a formidable challenge if not all impossible.

This research project is to develop and prove a novel approach for the exploration of multiphase flow and transport in porous media: the multiphase mixture model. The new model contains significantly fewer differential equations to solve, but remains to be a mathematically equivalent version of the conventional multiphase flow model, thus offering an attractive alternative for the theoretical analysis and numerical simulation. Through combined experimental and numerical studies, we intend to establish an efficient and routine tool to perform analyses of multidimensional multiphase flow and transport problems.

Two major areas are currently investigated. One area concerns twofers flow and heat transfer in porous media as widely encountered in energy conversion and electronics cooling. A highly efficient simulation model has been developed which can provide a routine tool for determining the two-phase dynamics and heat transfer in porous media. The computer model has been extensively validated by analytical solutions and benchmark experiments. The other area aims at developing a generic and efficient simulator for multiphase transport in relation to groundwater contamination and remediation. Advantage is taken of the two salient facts that the multiphase mixture model: (1) does not necessitate explicit tracking of phase interfaces nor primary variables switching, thereby providing an ideal formulation for the numerical modeling of multiphase flow and transport in porous media, and (2) reduces the number of differential equations almost by half and replaces them with algebraic relations in a mathematically equivalent fashion.

An earlier version of the simulator for two-phase, two-component systems has been available, while efforts are currently underway to develop a code for three-phase (i.e., gas, water and non-aqueousphase liquid), multicomponent systems.