A prediction study for the behaviour of fuel cell membrane subjected to hygro and thermal stresses in running PEM fuel cell.

A three-dimensional, multi-phase, non-isothermal computational fluid dynamics model of a proton exchange membrane fuel cell has been used and developed to investigate the hygro and thermal stresses in polymer membrane, which developed during the cell operation due to the changes of temperature and relative humidity. The behaviour of the membrane during operation of a unit cell has been studied and investigated under real cell operating conditions. The results show that the non-uniform distribution of stresses, caused by the temperature gradient in the cell, induces localized bending stresses, which can contribute to delaminating between the membrane and the gas diffusion layers. These stresses in the membrane may explain the occurrence of cracks and pinholes in the membrane under steady-state loading during regular cell operation. The results show that the maximum displacements in membrane for the low, intermediate and high load conditions were 2.58, 2.66, and 2.78 µ m respectively. [ABSTRACT FROM AUTHOR]