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影响因子：6.2

DOI码：10.1016/j.combustflame.2025.114138

发表刊物：Combustion and Flame

关键字：Differential diffusion, Flame stabilization, Supersonic hydrogen flames, Mixing layer, LES

摘要：Differential diffusion (DD) plays a crucial role in the fundamental understanding of combustion process, particular in the context of hydrogen or hydrogen-blended fuel flames. This paper intends to address whether the impact of DD on the flame stabilization in the turbulence-dominant supersonic flow can be negligible and if not, to elucidate its mechanisms. To this end, a spatially-developing supersonic non-premixed mixing layer hydrogen flame is simulated by large eddy simulations. Three distinct flow-chemistry interaction patterns: laminar flow-chemistry, transition-chemistry, and turbulence-chemistry are well designed within the mixing layer to examine the dependence of the DD effect on turbulence and its implications for flame stabilization. Results show that the importance of DD in flame-base zones of transition-chemistry and turbulence-chemistry interaction patterns is more pronounced than in laminar flow-chemistry one, even though their turbulence effects are more significant. The DD effect is observed to shorten the flame lift-off length and shift the leading point dynamic from a low-frequency to a high-frequency mode. Further “budget analysis” of transport- and chemistry- effect of DD shows that although the transport contribution of DD diminishes in turbulence-dominant flow-chemistry interaction patterns, the chemistry contribution of DD, i.e., sensitivity of the ignition delay time (IDT) to DD, is increased due to the low mixture temperature. Specifically, even a minor increase in the concentration of certain radicals, such as H, caused by DD can result in a significant reduction in IDT. This is primarily responsible for DD shortening the flame lift-off length within transition-chemistry and turbulence-chemistry interaction patterns. In laminar flow-chemistry pattern, DD facilitates the reaction to withstand high strain rates and in turn reducing the flame lift-off length.

论文类型：期刊论文

论文编号：114138

学科门类：工学

卷号：276

页面范围：114138

是否译文：否

发表时间：2025-06-01

收录刊物：SCIE

合写作者：Zhu Xu,Wang Nana