Direct numerical simulations (DNS) of laboratory-scale turbulent premixed Bunsen flames have been conducted and compared with an experimental dataset encompassing three methane–hydrogen flames with volumetric hydrogen fractions of and 70%. The Bunsen flames are representative of the strict flamelet regime of combustion with low turbulence intensity, which allows for the analysis of the effects induced by the combined action of Darrieus–Landau instability and non-unity Lewis number effects. The chemical aspect of DNS is treated using irreversible one-step Arrhenius chemistry, where the effective Lewis number has been determined based on a suitable calculation of the fuel mixture Lewis number along with an appropriate blending with the oxidiser Lewis number. A comparison between 2D experimental flame imaging and 3D DNS results reveals good agreement regarding mean flame shape, flame morphology, turbulent flame wrinkling, and turbulent burning velocity. This shows that simple chemistry simulations with appropriately chosen effective Lewis numbers can accurately describe turbulent burning velocity and flame–turbulence interaction for methane–hydrogen fuel blends. Provided emissions and ignition are not within the focus of the study, this might be very useful for conducting large-scale turbulent combustion simulations or large parametric studies of carbon-free or carbon-reduced fuels, which are enablers for the transformation of the energy industry into a climate-neutral circular economy.     «

Direct numerical simulations (DNS) of laboratory-scale turbulent premixed Bunsen flames have been conducted and compared with an experimental dataset encompassing three methane–hydrogen flames with volumetric hydrogen fractions of and 70%. The Bunsen flames are representative of the strict flamelet regime of combustion with low turbulence intensity, which allows for the analysis of the effects induced by the combined action of Darrieus–Landau instability and non-unity Lewis number effects. Th...     »