15.2.4 Wall Surface Mass Transfer Effects in the Energy Equation

Species diffusion effects in the energy equation due to wall surface reactions are included in the normal species diffusion term described in this section in the separate Theory Guide.

If you are using the pressure-based solver, you can neglect this term by turning off the Diffusion Energy Source option in the Species Model dialog box. (For the density-based solvers, this term is always included; you cannot turn it off.) Neglecting the species diffusion term implies that errors may be introduced to the prediction of temperature in problems involving mixing of species with significantly different heat capacities, especially for components with a Lewis number far from unity. While the effect of species diffusion should go to zero at Le = 1, you may see subtle effects due to differences in the numerical integration in the species and energy equations.