In this work we aim to develop a theoretical framework for evaluating the feasibility of attaining significant improvement of fuel cells performance and stability by enhancing the transport processes in porous partially-fluid-filled cathode compartments through applying acoustic and structural excitations. A generic unified model has been derived of the structural/acoustic wave propagation in the porous media with consideration of its coupling with mass transfer. It has been demonstrated that the phase saturation has a strong impact on the wave dynamics in porous media. Explicit expressions have been obtained for the generalized multiphase Biot-type coefficients. A generalized filtration equation has been derived that takes into account the effects on mass transfer of dynamic loading, varying saturation, and solid structure distortion in this complex system. For model calibration a series of tests has been conducted to measure water flows through porous media with and without acoustic excitations. It has been demonstrated that the excitations may result in a net change of the saturation inside the porous medium and the applied structural/acoustic loading can intensify the transportation process. Based on the numerical and experimental results, certain recommendations have been made in regards to the selection of materials and the optimization of performance regime.
Scale-dependent permeability and formation factor in porous media: Applications of percolation theory
