Flow distribution in a bipolar plate of a proton exchange membrane fuel cell: experiments and numerical simulation studies

An experimental and numerical research has been performed in order to study the flow distribution in a bipolar plate of a commercial PEM fuel cell. Planar laser induced fluorescence (PLIF)trace tracking has been applied to visualize the flow pattern and to measure the velocity in the plate channels. Simultaneously, the problem has been studied numerically, simulating the flow under similar operational conditions as those fixed in the experiments. Results obtained reveal a defective design of the bipolar plate. Based on the experimental visualization and on the numerical simulations it is concluded that the flow preferentially moves through the lateral channels, resulting in an inappropriate distribution on the electrode surfaces. Velocity measurements also confirm the above statements, showing high values at the lateral channels, while the flow is nearly stagnant in the central region. With this non-homogeneous flow distribution at the bipolar plate, a low performance of the fuel cell energy conversion could be expected