Three-dimensional numerical simulation of polymer electrolyte membrane fuel cells

A numerical three-dimensional prediction of a full cell (entire-cell) of a kind of polymer electrolyte membrane fuel cells (PEMFCs) was conducted by developing an in-house code. The isothermal single-phase model was adopted and the governing equations were discretized and solved in full fields. Moreover, the electrical current density was specified, and the output voltage of entire-cell was obtained by updating the over potential. The local current density distribution was also obtained by solving the Butler-Volmer equation, and its average value was then compared with the pre-specified one. The simulation results are in agreement with the experimental data. It is found that the local volumetric current density is in order of 1.0 × 10⁸ A/m³. Simulation was also conducted for a typical unit of the cell under the same operation condition. The results show the significant difference between the entire-cell simulation and the simulation of a typical computational unit (TCU) in the local distribution of current density and mass fraction. This might mainly result from the assumptions of uniform channel inlet and fully developed channel outlet in TCU. The present work confirms the importance to conduct the three-dimensional computation of entire PEMFCs.