Statistical approach and numerical analysis of turbulent diffusion flame of CH4/H2 mixture

Abstract

ABSTRACT In the present study, the methane/air turbulent diffusion flame enrichment by hydrogen, has been numerically investigated using a statistical approach. The countercurrent flame has been analyzed in the plane of the mixture fraction using the flame let approach. The chemical kinetics have been represented by the GRI Mech-3.0 mechanism, whereas the simulations have been performed with the PDF approach, and the modified k-ε turbulence model. Furthermore, the effect of the hydrogen addition to CH4/H2 melange with an amount of 0% to 20% was investigated; the flamelet model was first used to create a library of chemical characteristics of the laminar flame structure in the form as a mixture fraction Z-function. Next, we coupled the turbulent field to obtain the turbulent modeled flame structure with the modified k-ε model. The numerical results revealed that using the flamelet model allows an improvement of the mixture quality while adding hydrogen, whereas the maximum consumption zone occurs near the burner outlet, and the combustion temperature increases under the effect of hydrogen doping which reached 1884K, in which the NO mass fraction follows the same temperature evolutions.