Discrete Element Method (DEM) for Gas-Liquid Flows with Wall Interaction in Microchannels

In low-temperature fuel cells, liquid water condenses within the porous gas diffusion layer and is subsequently drawn into the gas microchannels. Efficient
water removal is essential for optimal performance. Uneven distribution and blocked channels cause flow maldistribution and can damage the cell. The
current range of multiphase models for large simulation domains is limited. Small domains are analyzed using the Volume of Fluid (VoF) method, while for
larger domains usually two-fluid models are utilized that ignore wall interaction, despite surface tension dominating in microchannels. We propose analyz-
ing droplet behavior in gas channels with a Discrete Element Method (DEM) based on an immersed boundary approach. This technique offers a significant
speed-up over VoF while producing comparable results and being more robust. With this method droplet detachment in a single channel and in two parallel
channels are analyzed.