Differential diffusion effects in numerical simulations of laminar, axi-symmetric H2/N2–air diffusion flames

• A new methodology to include differential diffusion was applied to laminar H2 flames.
• The accuracy of the methodology was verified against experimental data.
• Differential diffusion affected the stabilization mechanism of the flame.
• Differential diffusion affected the distribution of the species concentrations.
• Including differential diffusion resulted in lower maximum flame temperatures.

The accuracy of a new methodology to include differential diffusion in numerical simulations of reactive flows is illustrated for a set of laminar, axi-symmetric H2/N2–air diffusion flames. From the comparison of the calculations with the experimental data it is observed that when differential diffusion effects are properly taken into account in the transport equations in physical space, simulation results agree well with the experimental data. Ignoring differential diffusion effects is not acceptable, due to lack of H2 diffusion close to the jet inlet. Overall, differential diffusion has a strong influence on the stabilization of the flame as well as on the chemical species concentrations.