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

摘要

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 H-2/O-2 reaction mechanisms, as well as a detailed H-2/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 non premixed hydrogen combustion. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.