The purpose of this project is to develop advanced computational techniques in order to perform large-scale, state of the art simulations of two-phase transport problems arising in proton exchange membrane (PEM) fuel cells. Because of the complexity of the underlying mathematical models for fuel cells, current solution techniques are far from being satisfactory, and therefore more efficient numerical techniques are urgently needed. While there is still a long way before we can solve all the coupled systems efficiently, this proposal will be devoted to solution techniques for an important subsystem posted on the gas diffusion layers and the gas channel. This subsystem of equations possesses a number of critical numerical difficulties caused by anisotropy, large discontinuity, degeneracy and nonlinearity. The goal of the proposed project is to address these difficulties simultaneously by developing proper discretization techniques and robust iterative methods for solving the discretized systems. The discretization techniques to be developed will be mainly based on adaptive finite element/volume methods and the iterative methods will be based on multigrid techniques. The accuracy of the discretization scheme and the efficiency of the iterative methods for solving the discretized system will be studied.
The importance of the fuel cell technology can hardly be overemphasized as PEM fuel cell engines can potentially replace internal combustion engines in the future. Since a PEM fuel cell simultaneously involves electrochemical reactions, current distribution, two-phase flow multi-component transport and heat transfer, comprehensive mathematical modeling and computational simulation are required in order to: (1) understand the many interacting, complex electrochemical and transport phenomena that cannot be measured experimentally; (2) identify limiting steps and components; (3) simulate dynamic responses under vehicle driving conditions; and (4) provide a computer-aided tool for design of future fuel cell engines with much higher power density (kW/liter) and lower cost. The integration of the different expertise of the PI and co-PI is expected to lead to significant progress and likely breakthroughs in the field of fuel cell simulations. Newly developed numerical techniques will be immediately employed in the existing library of numerical codes that have been developed for years by the Penn State Electrochemical Engine Center (ECEC), lead by the co-PI. It is hoped that the new numerical techniques to be developed will lead to at least an order of magnitude improvement over the existing methods. Application and impact to national security/enviroment and to industries are naturally expected for this research because of the close tie of ECEC with national labs and automobile manufactures. Moreover, this work will provide a unique interdisciplinary research opportunity for graduate as well as undergraduate education.
