Effect of Waveform Gas Channel on Liquid Water Movement Emerging from GDL Pore with Lattice Boltzmann Method

Abstract

This paper aims to study the effect of waves from gas channels on the interaction of liquid droplets growing from two micropores in a wavy gas channel of PEMFC. The computational domain consists of a wavy gas channel in which liquid water is injected from two micropores with different diameters from the bottom of the computational domain. Also, the airflow entering the gas channel is fully developed with Poiseuille velocity. A multi-component multiphase pseudopotential Lattice Boltzmann method with a multi-relaxation time collision operator is present to simulate it. The forcing term in the collision operator has been improved to reach the real conditions of liquid water and air component density ratio and thermodynamic consistency. The different parameters such as Capillary number, temperature effect, wave amplitude, micropore diameter, and distance between two micropores on growth, detaching, and movement of liquid in the gas channel are studied. The simulation results indicate that by enhancing the Capillary number, the drag shear force rises, and the droplet detaches faster and improves its movement in the gas channel. Also, it is found that when the micropore diameter increases, the flow pattern changes from dripping flow to a continuous jet regime and raises the water removal time. The simulation is performed for a higher amplitude wavelength ratio to increase the maximum velocity, thus facilitating the droplet exit from the gas channel.