Evaluation of Liquid-Gas Two-Phase Flow Pressure Drop Signatures in Proton Exchange Membrane (PEM) Fuel Cell Flow Channels

In this study, liquid-gas two-phase flow pressure drops were measured in an ex-situ PEM fuel cell test section. Pressure drop signatures were studied for three nominal air flow rates and different water flow rates within a flow channel. The pressure drop signatures showed an increasing trend at the beginning of the experiments which were followed by a drop to lower values before reaching uniform patterns. It was observed that as the water flow rate increased, the time interval at which pressure signatures reached uniform patterns decreased. In addition, a qualitative comparison with Mishima-Hibiki model [13] revealed that this two-phase flow pressure drop model showed the best prediction capability for the medium air flow rate used in this study, ∼300mℓ/min inflow channel, corresponding to ∼220 Reynolds number.