Wolfgang and Ardalan [21] stated th

Wolfgang and Ardalan [21] stated that when the rate of removal of water is higher than that of water production through reaction, there may not be enough water to keep the electrolyte membrane hydrated which will cause it to dry out resulting in a drop of voltage in the PEM fuel cell and its overall efficiency. Dong et al. [22] concluded that rib structure and capillary force have a tremendous effect on liquid water transport and distribution in the GDL which could enhance the removal of water from the GDL to avoid water flooding. Carton et al. [23] modelled slug formation and droplet accumulation in the channels of a PEM fuel cell. They employed the Volume of Fluid (VOF) model in ANSYS Fluent to visualise the slug formation and water movement. Carton et al. [23] found out that coalescence of water droplets and excess water in the channels can lead to the formation of slugs in the cell and bends and steps in the flow channels could disrupt movement of slug and prevent channel blockage.