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Hydrogen is expected as new fuel instead of fossil fuel. It will be used as fuel of a fuel cell for which development is performed actively. But it is difficult to experiment the hydrogen dispersion in case of hydrogen leaks. Therefore clarifying the hydrogen dispersion with numerical analysis becomes important. Furthermore, hydrogen dispersion under various conditions can be clarified with numerical analysis, which is useful to use hydrogen safely. This paper deals with computer simulation of the hydrogen dispersion by a finite element method. The mathematical model of hydrogen dispersion is governed by the momentum equations, the continuity equation and the hydrogen mass conservation equation. The model presented here is a three-dimensional, incompressible, non-stationary model. This paper describes a finite element method with the stabilization technique for solving Navier-Stokes equations and the advection diffusion equation for hydrogen concentration like the Boussinesq approximation of thermal convection problems. Improved numerical results are also shown.

We demonstrate the feasibility of the domain decomposition method in simulating large scale finite element models through the ADVENTURE code, an open source freeware partly developed by the Computational Mechanics Laboratory at Kyushu University. Our model is that of hydrogen dispersion in a partially open space, chosen because of its relevance to the safe use of hydrogen as a potential replacement for fossil fuels. An analogy of the Boussinesq approximation is applied in our simulation. We describe the formulations and the model, followed by some results.

High SOFC operating temperature allows direct internal reforming (DIR) of methane within the SOFC anode. However, carbon formation reduces considerably the performance and durability of the cells. A key step towards improving SOFC performance is to understand the detailed surface kinetics and electrochemistry for DIR of methane at the triple phase boundaries (TPBs) in SOFC anodes. In this study, we have performed kinetic simulations with a numerical model on Ni pattern anode, combined with surface reactions, charge transfer reactions, and diffusions for DIR of methane. The I-V characteristics of SOFC near TPBs are discussed.

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