Enhancing polymer electrolyte membrane fuel cell efficiency through zigzag channel indentation design

For polymer electrolyte membrane fuel cells, channel indentation is a prevalent strategy for achieving higher power density. Zigzag dent arrangement in neighboring channels imposes a pressure difference between the adjacent channels which leads to enhanced over-rib convection and improved generated power at the expense of higher pumping power. In the present study, an optimization problem is formulated to maximize the net generated power as a function of the dent height ratio and the between-dent spacing. The computational domain consists of two parallel flow channels, which are investigated for three different channel lengths. A comprehensive numerical-statistical study is performed to determine the optimum dent height ratio and between-dent spacing that maximize the net generated power. Results reveal that the net generated power can be improved by 25.8% (fully blocking configuration), 17.6% (RSM-optimized configuration), and 13.3% (RSM-predicted and CFD-confirmed configuration) for L = 50, 100, and 300 mm, respectively.