Lattice Boltzmann simulations of liquid droplets development and interaction in a gas channel of a proton exchange membrane fuel cell

Liquid water transport in gas channels may influence and even prevent gas supply in a proton exchange membrane (PEM) fuel cell, so significantly affect cell operation. A two-phase two-dimensional lattice Boltzmann model is employed in this paper to simulate the development and interaction of two liquid droplets in a gas channel of a PEM fuel cell, focusing mainly on parametric effects, including the gas flow velocity, initial droplet distance, different micropore combinations, and the gas diffusion layer (GDL) surface wetting properties, on liquid droplet transport behaviors. Results confirm that an increased gas stream velocity and liquid pore distance may prevent liquid droplet interaction and enhance liquid water removal. Numerical simulations further indicate that different pore size combinations may promote droplet interaction, particularly with a large pore in front of a small one. On the contrary, a more hydrophobic GDL surface can decrease liquid droplet interaction, benefit liquid water removal, and consequently improve PEM fuel cell water management.