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In this study, the geometrical changes at cathode electrode in proton exchange membrane (PEM) fuel cell has been considered by inserting baffle plates across the channel. The effects of the blockage with various gap ratios, shape, thickness and numbers of the baffle plates, and the porosity of the diffusion layer on the oxygen transport and the pressure drop across the channel length are explored. It is revealed that partially blocked oxygen channel with rectangular baffle has the most velocity and oxygen concentration in the gas diffusion layer/catalyst layer interface than that of the other shape of plates; however results in a penalty of high pressure-loss. Increasing the porosity of gas diffusion layer (GDL), baffle plate thickness and baffle number and/or reducing the gap size in order to enhance the reactant gas transport result in pressure loss. Here, among the parameters considered, the porosity of GDL, gap ratio and plate number have the most remarkable impact on the oxygen transport to GDL and variation in pressure drop.

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In this study, we propose a configuration of partially blocked oxidant channel with baffle plates transversely inserted in the cathode channel and effects of the fluid dynamics due to the presence or non-presence of the baffles and their effect on the fuel cell performance is investigated. A 3D model with the presence of baffle plates is considered and a set of equations (continuity, momentum, species and charge together with electrochemical kinetics) in the form of single domain is developed and solved numerically. The baffles block the main flow in the cathode channel and force more reactant gases to turn to the GDL. This fact implies an enhancement of the oxygen flux at the GDL and catalyst surface, especially at the position beneath the location of the baffle plates. An increase in the number of baffles contribute to the reactant gas transport to GDL with more uniform distribution of gas in the GDL and catalyst layer, specially in high current densities, where it leads to a penalty of high pressure – loss. The predictions indicate that the local transport of the reactant gas would enhance the local current densities and the fuel cell performance in presence of baffle in the channel.