Assessment of a methodology to include differential diffusion in numerical simulations of a turbulent flame

•A new methodology to include differential diffusion in CFD is applied to a turbulent H₂ flame.•The accuracy of the methodology is verified by comparison to experimental data.•Differential diffusion affects the flame structure near the nozzle.•Differential diffusion affects the distribution of the species concentrations.•Differential diffusion allows predicting maximum temperatures higher than the adiabatic flame temperature.

A newly developed methodology to incorporate differential diffusion effects in CFD simulations of turbulent reactive flows is applied to the ‘H3’ benchmark flame of the Turbulent Non-premixed Flames (TNF) workshop series. The fuel consists of species with vastly different mass diffusivities. The accuracy of the proposed methodology is assessed and the influence of inclusion of differential diffusion is examined. Good agreement is obtained between numerical simulation results and experimental data if differential diffusion effects are considered. Differential diffusion effects are shown to be significant in the region near the inlet and have a great influence on the stabilization mechanism of the flame, as well as on the predicted profiles of temperature and species concentration. If differential diffusion is modeled, temperatures above the adiabatic flame temperature are recovered. Ignoring differential diffusion, this is not the case and large discrepancies between numerical simulations and experiments are observed.