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This study quantitatively describes the carbonate-and bicarbonate-forming reaction mechanisms in an operating alkaline exchange membrane fuel cell that occur as a result of carbon dioxide in the cathode gas stream. A transient, spatially-averaged theoretical model was created for this study and validated to experimental data from the literature. Results present the prediction of the membrane's ionic conductivity as a function of operating conditions and membrane properties. The self-purging phenomenon was observed and studied, as well as the emission of carbon dioxide from the membrane during operation. Following the conductivity study, suggestions can be made for optimal operating conditions and membrane properties to improve fuel cell performance in the presence of carbon dioxide.

This paper deals with the development of a procedure to model geometric variations of blades. Specifically, vibratory parameters of blades are extracted from coordinate measurement machine (CMM) data on an integrally bladed rotor (IBR). The method is based on a proper orthogonal decomposition of CMM data, solid modeling, and finite element techniques. In addition to obtaining natural frequencies and mode shapes of each blade on an IBR, statistics of these modal parameters are also computed and characterized. Numerical results are validated by comparison with experimental results.