On the computational fluid dynamics of PEM fuel cells (PEMFCs): an investigation on mesh independence analysis

Abstract

Mesh independence analysis is one of the most crucial steps in any CFD problem. The aim of this study was to investigate the most commonly used variables employed for grid independency studies in a typical PEMFC and to find possibly the most effective variables that may be decisive in a PEMFC grid independence test. Herein, a three-dimensional (3-D), steady state, non-isothermal computational fluid dynamics (CFD) model of a serpentine channel proton exchange membrane fuel cell (PEMFC) was developed. The present model includes various conservation equations that are dominant in a typical PEMFC: the mass, momentum, species, charge, and energy equations, which are coupled with the electrochemical model. The numerical results indicate that much more care should be taken while obtaining a mesh independence solution for CFD studies in PEMFC systems. Based on our findings in this study, it was demonstrated that employment of merely the polarization curve (current-voltage), especially only in a given specific point, was not sufficient to carry out the mesh independence tests for CFD studies in PEMFCs. In addition, it was observed that the average volumetric hydrogen concentration inside the catalyst layer on the anode side has a more significant role to check the grid independency tests.