Numerical investigation of fluid flow and cell performance at cathode of proton exchange membrane fuel cells

In this study, fluid flow and concentration distribution in cathode section of a PEM Fuel Cell were numerically investigated. The problem domain consists of cathode gas channel, cathode gas diffusion layer and cathode catalyst layer. The governing equations, continuity, momentum and concentration equations were discritized by the control volume method and solved using a computer program developed using SIMPLE algorithm. Comparing the results of numerical simulations and the result of analytical solution and results from literature, the mathematical model and program developed were tested. Simulations were made for different values of GDL porosity, Reynolds number and operation temperature. Using the results of these simulations, the effects of these parameters on flow, concentration and current density distribution were analyzed. It is determined that increasing the porosity of the gas diffusion layer increases current density of the PEM fuel cell, power density of the PEM fuel cell and oxygen concentration in catalyst layer. According to the simulations, it is also determined that increasing Reynolds number increases current density of the PEM fuel cell, power density of the PEM fuel cell and oxygen concentration incatalyst layer. Analyzing the data obtained from simulations shows that increasing operation temperature of PEM fuel cell increases current density of the PEM fuel cell and power density of the PEM fuel cell but decreases oxygen concentration in catalyst layer.Key Words : PEM Fuel Cells, Porous Medium, ConcentrationDistribution, Computational Fluid Dynamics