文献类型：期刊文献

英文题名：The influence of wall roughness on detonation limits in hydrogen-oxygen mixture

作者：Zhang, Bo[1]

机构：[1]E China Univ Sci & Technol, Key Lab Coal Gasificat & Energy Chem Engn, Minist Educ, Shanghai 200237, Peoples R China

年份：2016

卷号：169

起止页码：333

外文期刊名：COMBUSTION AND FLAME

收录：;EI(收录号：20162202434645);WOS:【SCI-EXPANDED(收录号:WOS:000378583600027)】；

基金：This work is supported by the National Natural Science Foundation of China (grant no.: 11402092), and the project of State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology (grant no.: KFJJ15-03M).

语种：英文

外文关键词：Detonation limits; Roughness; Cellular structure

摘要：In this study, wall roughness is generated by inserting a Shchelkin spiral with different wire diameter (8) and pitch (L-s). Roughness is defined as the ratio delta/L-5. The effect of tube wall roughness on the detonation limits in stoichiometric hydrogen-oxygen mixture is systematically examined. The detonation velocity is determined from optical fibers and shock pins spaced at 10 cm intervals along the tube. Smoked foils are employed to record the cellular detonation structure near the limits. The experimental results indicate that detonation in both smooth and rough sections can be self-sustaining and can propagate with a steady velocity as the conditions are well within the detonation limits. However, the detonation velocity decreases as it transmits into the rough-walled tube. The velocity deficit is more significant in tubes with larger roughness due to the interaction of the detonation reaction zone and the boundary layer formed behind the shock. Single-headed spinning structure is observed as the detonation approaches the limits in the rough-walled tube. Below the minimum initial pressure at which single-headed spinning phenomena occur, detonation fails and decays to deflagration, and the minimum velocity is approximately 0.4V(CJ). It is found that wall roughness can either promote or prohibit the detonation propagation limits. When the roughness is smaller than 0.231, it is believed the turbulence generated from the roughness facilitates detonation and extends the detonation limits. However, when the roughness is larger than 0.333, low-velocity behavior plays a dominant role in prohibiting the detonation, which indicates that roughness above a certain level has a negative effect on detonation limits. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.