Research on the Scale Coefficient in the Interface Leakage Rate Multi-scale Model and the Performance Study of the Gasket-BPP Sealing Interface in PEMFCs

The existing of rough asperities on the surfaces of rubber Gaskets and metal BPPs at microscopic scales is the basic reason why the gas leaks from the sealing interface. Characterizing the non-smooth asperities of the sealing interface is crucial to realize the calculation and analysis of the leakage rate. But the microscopic features are strongly related to the observation scale, so the multi-scale interface leakage prediction model is established to exclude the negative influence on modeling micro-scale rough surfaces of a single observation scale. In this paper, the scale coefficient in the multi-scale model is studied to improve the accuracy of the interface leakage rate multis-scale model by analyzing the linear relationship between the interface leakage rate and the volume of the leakage channel. Continuously based on the multi-scale model which maintains the studied scale coefficient, the interface leakage rates of different Gasket-BPP sealing structures are investigated. And the reliability and accuracy of the multi-scale model are verified by comparing to the traditional interface leakage model.