Dept. of Mechanical Engineering, Urmia University of Technology, Urmia, I. R. of Iran
Modeling the heat and mass transport in micro channel is being used extensively in researches and industrial applications. The aim is optimizing fuel cell designs before building a prototype for engineering application. In this study, numerical, three-dimensional, single phase computational fluid dynamics model of a proton exchange membrane fuel cell with both the gas distribution flow channels and the Membrane Electrode Assembly (MEA) has been developed. A single set of conservation equations which are valid for the flow channels, gas-diffusion electrodes, catalyst layers, and the membrane region, are solved by finite volume technique. The present simulated straight channels PEMFC model, accounts for major transport phenomena and the performance. Additionally, the effect of reversing the flow direction at cathode side has been investigated to study the fuel cell performance and species distribution. The results showed that, in the PEMFC with the counter flow channels, the output current density has been decreased and also the kind of species distributions has been influenced by this phenomenon. It is very important to model the back diffusion and electro-osmotic mass flux for determination of ionic conductivity of membrane which affects the performance of fuel cell. Finally, the numerical results are validated by available experimental data.