Living organisms have optimized how fluid flows through their systems over thousands of years of evolution. Studying these natural structures can inspire better flow field designs for fuel cells by improving the gas distribution and water management within the cell. To evaluate the effectiveness of this design principle, Dong et al. studied the performance and properties of fuel cell flow fields inspired by four-leaf clovers.
Though previous research has looked at fuel cell designs inspired by biological features, the authors combined this approach with Murray’s law, which describes the most energetically efficient relationship for the diameters of individual veins in a leaf. Using numerical simulations of the cells’ electrochemical reactions, they compared their model with another clover-inspired field design but without the use of Murray’s law, as well as a design based on a traditional fuel cell structure.
By including the consideration of Murray’s law, they found their design outperformed both the traditional and four-leaf clover system. With a significant reduction in pressure drops within the flow channels and an increase in gas distribution uniformity, the Murray’s law approach enhances the maximum power of the cell by up to 114% as compared to traditional designs.
“For fuel cells with a large active area, using this bio-inspired structure can improve the uniformity of fuel distribution in the fuel cell and improve the water management performance,” said author Shihua Liu.
Currently, the group’s bio-inspired flow field can only be used in a single fuel cell due to the structure of its gas inlet. They plan to dedicate future studies to improve upon this structure, so it can be applied to an entire fuel cell stack.
Source: “Numerical investigation of novel bio-inspired flow field design scheme for PEM fuel cell,” by Jinhua Dong, Shunfang Liu, and Shihua Liu, Journal of Renewable and Sustainable Energy (2020). The article can be accessed at https://doi.org/10.1063/1.5137761.
