The following study investigates the heat and mass transfer of a tubular solid oxide fuel cell using computational fluid dynamics. The model developed was used to parametrically study three aspects of solid oxide fuel cell simulation;​ (i) electrochemistry, (ii) thermal radiative heat exchange with participating media, and (iii) the distribution of heat generation associated by the entropy of the electrochemical reaction.

Two electrochemical models were developed. The first was a uniform current density model, while the second calculated the current source based on the local temperature, and the concentrations of fuel and oxidant. Modelling electrochemistry with a dependence on these conditions has moderate influence on the cell temperature.

Thermal radiative heat exchange was considered to occur by both surface-tosurface and participating media mechanisms. When modelling radiatively absorbing gases, the discrete ordinates method was used for spatial discretization, and water was considered to be the participating gas molecule. Simulation results show that including radiative exchange has a large impact on the fuel cell’s temperature field, and indicate that radiation cannot be ignored when modelling a SOFC. However it was also concluded that participating media plays a minor role in the effective heat exchange.

Varying the location of the reversible heat generation in the fuel cell was investigated and its influence on the cell temperature was minor. Overall, lower system temperatures resulted when heat was released on the cathode side, due to an enhanced cathode channel cooling effect.

Finally, a factor affecting the temperature field in all three studies was the air supply tube. This is vital to include in a model of a tubular SOFC designed with one, as its lower surface temperature at the air supply inlet drastically changes the temperature field in this region of the cell. It is also greatly affected by radiation exchange with the fuel cell surface.