Mass transport in Channels with Porous Walls

Mass transport between the bulk and a surface arises in a variety of applications ranging from catalytic converters to oxygen transport in the lungs. These settings typically involve channels with porous walls to maximize surface-to volume ratio. Mass flux is controlled by three separate physical processes: transport from the bulk to the channel walls, transport through the pores, and finally absorption/desorption at the surface. By using a combination of simulation and experiments, we investigate transport in the channel and the pores under laminar flow conditions. The impact of porosity on oxygen, carbon dioxide, and water concentrations in a gaseous mixture is quantified for a range of flow speeds, pore fraction, and tortuosity.