The effects of chemical kinetic mechanisms on large eddy simulation (LES) of a nonpremixed hydrogen jet flame

•A nonpremixed hydrogen flame was simulated using LES with detailed chemistry.•Effects of five different kinetic mechanisms on the LES results were examined.•The linear eddy model was employed for the turbulence-chemistry interactions.•Detailed H2/O2 mechanisms lead to reasonable agreements with experimental results.

Five different chemical mechanisms for hydrogen combustion are employed in large eddy simulation of a nonpremixed hydrogen jet flame to investigate the ability of these mechanisms to represent the turbulence-chemistry interactions and other combustion phenomena. The mechanisms studied include a reduced mechanism, two detailed H2/O2 reaction mechanisms, as well as a detailed H2/CO mechanism and the GRI3.0 mechanism. Linear eddy model is incorporated to evaluate the effect of turbulence-chemistry interactions. Extensive simulations of a well-known experimental case (German Aerospace Centre DLR nonpremixed flame M2) have been performed for the purpose of validation. Comparisons against experimental data including scalar distribution profiles are presented where a reasonable agreement is observed for the detailed mechanisms. Flux analyses of the species conservation equations and ignition delay time tests showed that chemical kinetics plays a role in the development of flame structures in the jet flame. This study highlights the importance of precise descriptions of the chemical kinetics in LES of nonpremixed hydrogen combustion.