A method based on fluid-structure interaction to improve the uniformity of contact pressure in fuel cell stacks

The assembly of proton exchange membrane fuel cell (PEMFC) stacks presents a challenge in engineering, where the assembly methods of the stacks affect the distribution of contact pressure on key components. Therefore, a hydraulic thin-walled vessel is designed that leverages fluid-structure interaction (FSI) between the internal fluid and walls to improve the uniformity of the contact pressure in stacks. Firstly, PEMFC stack models under bolt and belt assembly methods are created, and the equivalent stiffness model is applied to simplify the models. Focusing on the reacting region of the membrane electrode assembly (MEA), the coefficient of variation (CV) of contact pressure is employed to quantify the uniformity of contact pressure inside the stacks with and without the vessels. Fluid cavity method is introduced to model the FSI. Numerical simulation demonstrates that the uniformity is worse in MEA near end plates, and the improvement in uniformity realized by the vessel is more pronounced in such regions. For the stack embedded with the vessel under bolt assembly, the maximum improvement in contact pressure uniformity reaches 22.77 %, while under belt assembly, the maximum improvement reaches 14.76 %. This study provides a new approach for improving the uniformity of contact pressure inside the large stack.