A novel 3D fine-mesh flow field design and performance analysis for proton exchange membrane fuel cells

Optimizing flow field structures plays a crucial role in enhancing the mass transfer of reactant gas and improving the output power density of proton exchange membrane fuel cells (PEMFCs). Herein, a PEMFC model with a three-dimensional (3D) fine-mesh flow field is developed and investigated in detail using a 3D computational fluid dynamics (CFD) model. The flow velocity, oxygen partial pressure and oxygen molar fraction distribution in the 3D fine-mesh flow field are analyzed and compared with the parallel flow field. The numerical simulation results show that as the porosity of the 3D fine-mesh structure increases, the local flow velocity increases, the oxygen partial pressure drop decreases, and the oxygen molar fraction increases, which are conducive to improving the output performance of fuel cells. At an operating voltage of 0.4 V, the peak power density of the 3D fine flow field model with a porosity of 0.9 is 21.5% higher than that of the parallel flow field model.