Flame acceleration process and detonation transition in a channel with roughness elements on a wall
Flame acceleration process and detonation transition in a channel with roughness elements on a wall
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壁面粗糙元通道内的火焰加速过程和爆轰转变
DOI：
10.1016/j.proci.2022.07.224
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发表时间：
2022
影响因子：
3.4
通讯作者：
Obara Tetsuro
中科院分区：
文献类型：
--
作者：
Maeda Shinichi;Irokawa Masahiro;Taneichi Daiki;Obara Tetsuro
实验研究了壁面粗糙度对火焰加速和燃烧转爆轰（DDT）的影响。我们先前的实验（Maeda等人，2019）使用砂纸状不规则粗糙度表明，火焰加速和相关的DDT大大增强的粗糙度。在这项研究中，CH* 化学发光成像以及纹影成像与使用通道中的乙烯-氧气燃烧的压力测量并行进行（486毫米长，10毫米正方形横截面），具有常规粗糙度（底部长度和高度为1 mm的正方形棱锥元件），以便直接连接流动之间的干扰，粗糙度和火焰传播表面对化学反应场的影响导致了化学反应的增强，而在以前的研究中，单独的纹影成像不能允许讨论化学反应场。在初始指状火焰加速过程形成前导激波后，在火焰前缘上观察到与粗糙元件附近未反应气体的流场和压力扰动的多重相互作用。结果表明，粗糙度强化了边界层的影响，扰动层与火焰相互作用的区域与化学发光图像中强烈的化学反应相吻合，表明火焰前缘的湍流增加了火焰表面积，燃烧速度的粗略估算也验证了这一点.在火焰表面附近的粗糙元素的壁面处观察到爆轰开始。最后的爆轰转变的可能因素被推断为热点的形成的基础上的压力波与粗糙元素的多重相互作用和夹带的未反应气体的高度湍流火焰前锋。
We experimentally investigated the effect of small roughness elements, which could be regarded as the wall roughness, on flame acceleration and deflagration-to-detonation transition (DDT). Our previous experiments (Maeda et al., 2019) using the sandpaper-like irregular roughness indicated that the flame acceleration and the associated DDT were greatly enhanced by the roughness. In this study, CH* chemiluminescence imaging as well as schlieren imaging was conducted in parallel with pressure measurements using an ethylene-oxygen combustion in the channel (486 mm long, 10 mm square cross-section) with the regular roughness (square pyramid elements with a base length and a height of 1 mm) in order to directly link the interference between the flow-field affected by the roughness and the propagating flame surface resulting the enhancement of chemical reactions, whereas the schlieren imaging alone could not allow to discuss the chemical reaction field in the previous study. After the leading shock wave was formed by the initial finger flame acceleration process, multiple interactions were observed on the flame front with the flow-field and pressure disturbances of the unreacted gas near the roughness elements. The results provided clear evidence that the roughness emphasized the effect of boundary layer, and the region where the disturbance layer and the flame were interacting coincided with the strong chemical reaction in the chemiluminescence image, indicating increase of the flame surface area caused by the turbulence on the flame front, which was also validated by the rough estimation of the burning velocity. The detonation onset was observed at the flame surface near the wall with the roughness elements. The possible factors of the final detonation transition were deduced to be the hot spot formation based on the multiple interactions of pressure waves with the roughness elements and entrainment of the unreacted gas of the highly turbulent flame front.
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影响因子：
2.2
作者：
S. Maeda;S. Minami;D. Okamoto;T. Obara
通讯作者：
S. Maeda;S. Minami;D. Okamoto;T. Obara
爆炸性气体中的初始火焰加速
DOI：
10.1098/rspa.1962.0132
发表时间：
1962
期刊：
Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences
影响因子：
--
作者：
A. Laderman;A. K. Oppenheim
通讯作者：
A. K. Oppenheim
表面粗糙度对亚毫米通道中爆燃到爆炸转变的影响
DOI：
--
发表时间：
2017
期刊：
--
影响因子：
--
作者：
R. Houim;E. Oran
通讯作者：
E. Oran
DOI：
10.1016/j.proci.2014.08.002
发表时间：
2015
期刊：
--
影响因子：
--
作者：
M. Kellenberger;G. Ciccarelli
通讯作者：
G. Ciccarelli