TABLE OF CONTENTS Modeling studies for three types of fuel cells were reviewed in this chapter with particular focus on the transport and electrochemical processes within the cells. The physical phenomena and their governing equations for the overall cell as well as individual cell components were elucidated. Example results were presented on the performance of fuel cells under various design and operating conditions, and the use of the theoretical models for application considerations of cell optimization and design under uncertainty was demonstrated. The Chapter provides a compendium of advances in the modeling of fuel cells, to form the foundation for future developments. While several significant advances have been made with regard to the theoretical description and computational modeling, several challenges remain to be addressed, some of which are noted below.
Model validation remains an important issue toward improving the fidelity and the predictive capability of the computational developments. Presently, the models are routinely compared to overall polarization data, whereas more detailed validation with regard to the concentration and temperature profiles is less common. Moreover, comparisons of the models with experimental data are made mostly in a correlation sense, whereby several of the model parameters are fitted to match the experimental data. It is well known that the same polarization curve may be fitted by multiple parameter combinations, which, in turn, may correspond to dramatically different flow and reaction conditions within the cell. A related issue is the large scatter in the values of the material properties and model parameters reported...
