| Summary: | 碩士 === 國立中央大學 === 機械工程研究所 === 98 === The main purposes of this study are to investigate the use of metal foam as the flow distributor of proton exchange membrane fuel cells (PEMFCs) and the effects of flow field design on the transport phenomena and the performance of the fuel cells. A three-dimensional mesh system was built by using the GAMBIT and the discredited equations were solved by the CFD software FLUENT. Results of flow, mass, pressure, and electric distributions under real operating conditions are presented and discussed.
Based on the results, for single entrance designs, the pressure drop increases as the number of partitions increases. This increase in pressure drop results in enhanced transport of reactants in the through-plane direction. Therefore, reaction rate as well as cell performance increase. As for the comparison between single inlet and multiple inlets, although multiple inlet design has lower pressure drop, it causes lower cell performance due to uneven flow distribution among different partitions.
In addition, cell performance was found to increase slightly if the reactant gas was humidified, the pore size of the metal foam was reduced, or the foam/carbon paper was slightly compressed.
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