Introduction

The sofcFoam model is an OpenFOAM application for the simulation of solid oxide fuel cells. It is a single-cell and multi-cell stack model being developed within the open source Multi-Scale Integrated Fuel Cell (MuSIC) project. This document describes how to obtain and use sofcFoam.

To make more sense of what follows, it may be useful to begin with a brief overview of the model. (A more detailed view will be provided later). The model simulates a four region fuel cell, as depicted schematically in Figure 1(a). Between two interconnects we find an air region, an electrolyte, and a fuel region. The model uses a computational domain for each of these regions, and one more global domain for the entire cell. Each domain supports its own fields. Pressure, momentum and species mass fractions, for example, are solved on the air and fuel domains, and temperature is solved on the global domain. Global and regional information is transferred back and forth via grid cell mappings that are established during mesh generation/splitting. Porous cathode and anode zones, shown in Figure 1(b), are incorporated into the air and fuel regions, respectively, using Darcy’s Law. Electrochemistry is assumed to occur on the electrode-electrolyte interfaces. The resulting electrochemical mass fluxes give rise to Dirichlet velocity conditions and Neumann mass-fraction conditions on the air and fuel boundaries interfacing the electrolyte.
After an initialization phase, the model enters an iteration loop as follows:

1. global temperature is mapped to the fluid regions, air and fuel
2. fluid densities are calculated
3. pressure and momentum are solved in fluid domains
4. mass diffusivity in fluids is calculated
5. mass fractions of fluid species are solved
6. electrochemistry is calculated
7. regional velocity and thermophysical data fields are mapped to global mesh
8. energy equation is solved for global temperature
9. Steps (1) to (8) are repeated until convergence