In this article, a two dimensional pore scale model of polymeric fuel cell, which is promising of a clean and renewable energy production, is presented here. Let reactive gases behave as an ideal gas; inhomogeneous anisotropic structure of the gas diffusion layer, is contemplated as a random generated circular porous media. Lattice Boltzmann method is applied to inquire the fluid flow and mass ...

in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

modeling the heat and mass transport in micro channel is being used extensively in researches and industrial applications. the aim is optimizing fuel cell designs before building a prototype for engineering application. in this study, numerical, three-dimensional, single phase computational fluid dynamics model of a proton exchange membrane fuel cell with both the gas distribution flow channels...

the problem of combined heat and mass transfer of an electrically conducting fluid in mhdnatural convection adjacent to a vertical surface is analyzed, taking into account the effects of ohmic heatingin the presence of suction or injection. an approximate numerical solution for the steady laminar boundarylayerflow over a wall of the wedge in the presence of species concentration and mass diffus...

We obtain a limit when mass tends to zero of the relativistic diffusion of Schay and Dudley. The diffusion process has the log-normal distribution. We discuss Langevin stochastic differential equations leading to an equilibrium distribution. We show that for the Jüttner equilibrium distribution the relativistic diffusion is a linear approximation to the Kompaneetz equation describing a photon d...

In this paper we investigate the effects of element diffusion on the structure and evolution of low-mass helium white dwarfs. Attention is focused mainly on the occurrence of hydrogen shell flashes induced by diffusion processes during cooling phases. Physically sound initial models with stellar masses of 0.406, 0.360, 0.327, 0.292, 0.242, 0.196, 0.169 and 0.161 M⊙ are constructed by applying m...

Restricted water diffusion has been used to distinguish pyogenic abscess from other rim-enhancing brain masses; however diffusion-weighted imaging of cerebral infection before capsule formation has rarely been described. We report a case of fungal cerebritis in which water diffusion was more restricted than that of normal contralateral brain and the measured diffusion coefficient was in the ran...

In this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (GDL) of PEM fuel cell is modeled. The governing equations including energy, mass and momentum conservation equations are solved by numerical methods. Also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (GDL) thickness and inlet relative humidity are calculated...

In this paper as a development of recently introduced analytical approach for estimation of temporal characteristics of mass and heat transport we present analysis of diffusion depth of dopant in a material with time varying diffusion coefficient. It has been shown, that changing of time dependence of diffusion coefficient gives a possibility to accelerate or decelerate diffusion process. In th...

The diffusive motion of foreign particles dispersed in a premelting solid is analyzed within the framework of irreversible thermodynamics. We determine the mass diffusion coefficient, thermal diffusion coefficient and Soret coefficient of the particles in the dilute limit, and find good agreement with experimental data. In contrast to liquid suspensions, the unique nature of premelting solids a...