This research reports a feasibility study into multi-scale polymer electrolyte fuel cell (PEFC) modelling through the simulation of macroscopic flow in the multi-layered cell via 1D electrochemical modelling, and the simulation of microscopic flow in the cathode gas diffusion layer (GDL) via 3D single-phase multi-component lattice Boltzmann (SPMC-LB) modelling. The heterogeneous porous geometry...

Abstract. We investigate the asymptotic behaviour of the wetting front arising from unsaturated flow in porous media wherein the liquid saturation θ obeys a nonlinear diffusion equation having moisture diffusivity that is an exponential function D(θ) = Do exp(βθ). For values of the physical parameters corresponding to actual porous media, the diffusivity at the residual value of saturation is D...

In this paper we report on a thermoelectric generator (TEG) using thermal isolation provided by a thick porous Si layer locally formed on the Si wafer and thermocouples composed of p-doped polycrystalline Si/Al. The "hot" contacts of the thermocouples lie on the porous Si layer, while the "cold" contacts lie on bulk crystalline Si. A housing was also designed and fabricated in order to transfer...

An interconnected set of algorithms is presented for the simulation of two-phase ow in porous media achieving more than two orders of magnitudes acceleration. The accuracy and e ciency of the approach is demonstrated through 2D and 3D numerical experiments for a range of two-phase porous media problems involving single cracks, heterogeneous permeability, and hydrophobic and hydrophilic media

We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer sh...

A new model for turbulent flows in porous media is developed. The spatialand time fluctuations in this new model are tied together and treated as a single quantity. This novel treatment of the fluctuations leads to a natural construction of the k and e type equations for rigid and isotropic porous media in which all the kinetic energy filtered in the averaging process is modeled. The same terms...

In this paper we discuss the formulation of the governing equations that describe ow of uids in porous media Various types of uid ow ranging from single phase ow to compositional ow are considered It is shown that all the di erential equations governing these types of ow can be e ectively rewritten in a fractional ow formulation i e in terms of a global pressure and saturation or saturations an...

In this paper, the passive control of flow past a semi-circular cylinder is investigated. This control is achieved by adding a porous medium between the solid obstacle and the incompressible fluid in order to reduce drag forces and regularize the flow. A vortex-penalization method is chosen to easily model the flow in the different media. Several configurations of the porous layer are investiga...