Cellular pattern evolution in gaseous detonation diffraction in a 90°-branched channel
Cellular pattern evolution in gaseous detonation diffraction in a 90°-branched channel
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DOI：
10.1016/j.combustflame.2006.11.001
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发表时间：
2007-02
影响因子：
4.4
通讯作者：
Changming Guo;Changjian Wang;Shengli Xu;Hanhong Zhang
中科院分区：
文献类型：
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作者：
Changming Guo;Changjian Wang;Shengli Xu;Hanhong Zhang
本文介绍了气相爆轰波在90°分支通道中衍射的最新实验研究结果。衍射的整个过程由细胞图案展示，并且分析主要基于它们的演化。爆轰压力的历史和速度进行了测量和相应的蜂窝图案被记录在烟炱箔周围的分支段。结果表明，爆轰波的传播受到分支壁面几何形状的显著干扰，在两个通道中都出现了复杂的波型。胞格图显示，在T形连接区域出现膨胀扇，在水平通道中发生马赫反射，而在垂直通道中发生规则反射。随后，在垂直通道中出现了从规则反射到马赫反射的过渡。详细的细胞图案表明，从早期阶段的衍射结束，爆轰波依次经历衰减，前解耦，并退化到爆燃，重新启动，和恢复。根据蜂窝图案的演变和速度测量，恢复爆震与几乎相同的速度作为未受干扰的入射波最终发展下游在两个通道，在距离约四倍的通道高度（160毫米）。基于ZND（Zel'dovich-von Neumann-Döring）模型对衍射机理进行了探讨，两个通道中的烟炱箔都显示出与90°分支通道中空气激波衍射一致的图案。
This paper presents recent results of an experimental investigation on gaseous detonation diffraction in a 90°-branched channel. The entire process of diffraction is demonstrated by cellular patterns and the analysis is mainly based on their evolution. Detonation pressure history and velocity are measured and the corresponding cellular patterns are recorded on soot foils around the branched segment. Results show that detonation propagation is notably disturbed by the branched wall geometry and that a complex wave configuration appears in both channels. Cellular patterns show that an expansion fan appears at the T-junction area with a Mach reflection taking place in the horizontal channel, while regular reflection takes place in the vertical channel. Subsequently, it appears that there is a transition from a regular reflection to a Mach reflection in the vertical channel. Details of the cellular pattern indicate that from the early stage to the end of diffraction, the detonation wave sequentially experiences attenuation, front decoupling, and degradation into deflagration, reinitiation, and recuperation. According to cellular pattern evolution and velocity measurement, a recuperated detonation with nearly the same velocity as the undisturbed incoming wave finally develops downstream in both channels, at a distance of about four times the channel height (160 mm). The mechanism of diffraction is explored based on the ZND (Zel'dovich–von Neumann–Döring) model, and the soot foils in both channels show a pattern consistent with air shock-wave diffraction in a 90°-branched channel.