Wave-shaped flow channel design and optimization of PEMFCs with a groove in the gas diffusion layer

The effects of the wave-shaped flow channel structure and a groove in the gas diffusion layer (GDL) on the net power density of proton-exchange membrane fuel cells (PEMFCs) are investigated. A three-dimensional, two-phase, steady-state, and isothermal numerical model of PEMFCs is established. The amplitude and the number of wavy cycles play an important role in improving the performance of fuel cells, and the optimization of the wave-shaped flow channel to obtain the optimal flow channel structure is performed using the genetic algorithm. Furthermore, regarding the optimal wave-shaped channel, the mass transfer effect can be improved by introducing a groove structure into the GDL for gas diffusion. Thus, two parameters, i.e., groove position and depth, are optimized, and the output power and power consumption are also considered. According to the results, the wave-shaped flow channel with a groove in the GDL exhibits high efficiency. The optimal flow channel has an amplitude of 0.643 mm, the number of wavy cycles of 9, and the groove position and depth of 9.5 and 0.05 mm, respectively, and the net power density can be increased by 2.64%. • Wave-shaped flow channel with a groove was firstly considered in the GDL of PEMFCs for its design and optimization. • The amplitude of wave-shaped flow channel has a greater effect than the number of wavy cycles. • The diffusive oxygen flux is influenced by the position of a groove in the gas diffusion layer. • A groove in the gas diffusion layer can enhance the mass transfer effect and improve the fuel utilization.