Analytical approach to investigate the effect of gas channel draft angle on the performance of PEMFC and species distribution

An analytical procedure is presented based on the perturbation technique to solve the governing equations of the reactant gas flow in the gas channels of a PEMFC draft angle. The equations are solved in both the anode and cathode gas channels with conveniently defined perturbation parameters to achieve the velocity, species concentration and temperature profile in the gas channels. By increasing the draft angle (theta), the maximum section of the velocity profile tends toward the bottom of the gas channel. In addition, the maximum magnitude of the velocity is enhanced by increasing the draft angle magnitude. Also by furthering the draft angle, the amount of the species which transfer into the reaction area is increased too. Accordingly the concentration of species is reduced along the channel. Enhancing the draft angle magnitude increases the temperature gradient in the longitudinal direction, while reduces the temperature at the entrance region of the channel. The best draft angle is about 10 degrees to 20 degrees for optimal velocity, species concentration and cooling through the gas channel. The analytical results are verified with 3-D numerical simulation. The gas channels with draft angle, enhance the performance of PEMFC in the comparison by the channel without the draft angle. It means that, draft angle improves the performance of PEMFC by modifying the species concentration distribution and penetration through the PEMFC. (C) 2020 Elsevier Ltd. All rights reserved.