Different modes of reaction front propagation in n-heptane/air mixture   with concentration non-uniformity

doi:10.1016/j.proci.2016.06.086

CORC > 北京大学 > 工学院

	Different modes of reaction front propagation in n-heptane/air mixture with concentration non-uniformity
	Qi, Chengken ; Dai, Peng ; Yu, Hao ; Chen, Zheng
刊名	PROCEEDINGS OF THE COMBUSTION INSTITUTE
	2017
关键词	Autoignition modes Detonation development Concentration non-uniformity n-Heptane DIRECT NUMERICAL SIMULATIONS SPHERICAL FLAMES HIGH-PRESSURE HOT-SPOTS AUTOIGNITION IGNITION TEMPERATURE DETONATIONS INITIATION REGIME
DOI	10.1016/j.proci.2016.06.086
英文摘要	According to the reactivity gradient theory of Zel'dovich, the non-uniformity in temperature or concentration can lead to detonation development under certain conditions. In the literature, there are many studies on detonation development caused by temperature gradient or hot spot. However, the modes of supersonic reaction front propagation and detonation development regime caused by concentration non-uniformity have not been investigated previously. In this study, one-dimensional simulations were conducted to investigate the transient autoignition and reaction front propagation processes in n-heptane/air mixture with concentration non-uniformity. With the increase of equivalence ratio gradient, three modes (supersonic autoignitive reaction front, developing detonation and subsonic reaction front) of reaction front propagation induced by concentration non-uniformity were identified. The effects of heat conduction and mass diffusion on these three modes were examined and it was demonstrated that molecular diffusion has little influence on the first two modes. The detonation development regime caused by concentration non- uniformity was reported in this paper. This regime was found to be similar to the one caused by temperature gradient. A non-dimensional parameter was proposed to characterize the lower limit of the detonation regime. Furthermore, the effects of initial temperature on the detonation development regime were examined. It was found that the detonation development regime becomes wider as the initial temperature decreases. The initial temperature was shown to only have great impact on the upper limit of the detonation development regime while it has little influence on the lower limit. The influence of initial temperature was explained using the volumetric energy density of the mixture. (C) 2016 by The Combustion Institute. Published by Elsevier Inc.; National Natural Science Foundation of China [51322602]; SCI(E); ARTICLE; 3; 3633-3641; 36
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/476405]
专题	工学院
推荐引用方式 GB/T 7714	Qi, Chengken,Dai, Peng,Yu, Hao,et al. Different modes of reaction front propagation in n-heptane/air mixture with concentration non-uniformity[J]. PROCEEDINGS OF THE COMBUSTION INSTITUTE,2017.
APA	Qi, Chengken,Dai, Peng,Yu, Hao,&Chen, Zheng.(2017).Different modes of reaction front propagation in n-heptane/air mixture with concentration non-uniformity.PROCEEDINGS OF THE COMBUSTION INSTITUTE.
MLA	Qi, Chengken,et al."Different modes of reaction front propagation in n-heptane/air mixture with concentration non-uniformity".PROCEEDINGS OF THE COMBUSTION INSTITUTE (2017).