Effects of thermal stratification and turbulent intensity on auto-ignition and combustion mode transition
文献类型：期刊论文
| 作者 | Pan, Jiaying1; He, Yu1; Wang, Lei1; Li, Tao2; Wei, Haiqiao1; Shu, Gequn1 |
| 刊名 | COMBUSTION AND FLAME
 |
| 出版日期 | 2022-10-01 |
| 卷号 | 244页码:16 |
| 关键词 | Engineknocking Thermalstratification Turbulentintensity Detonationdevelopment Supportvectormachine |
| ISSN号 | 0010-2180 |
| DOI | 10.1016/j.combustflame.2022.112273 |
| 通讯作者 | Wei, Haiqiao(whq@tju.edu.cn) |
| 英文摘要 | Hydrogen engines with zero-carbon emissions have recently drawn attention while they often suffer from pre-ignition and knocking issues. It is generally understood that knocking intensity is closely as-sociated with auto-ignition development modes, which are affected by multiple variables and their in-teractions. In this work, the role of thermal stratification and turbulent intensity in auto-ignition de-velopment modes were numerically investigated, addressing combustion mode transition. Representative end-gas auto-ignition conditions were employed for hydrogen/air mixtures. Meanwhile, the support vec-tor machine (SVM) algorithm was first applied in the predictions of detonation development. The results show that thermal stratification plays a decisive role in auto-ignition development modes, and supersonic auto-ignition deflagration, direct detonation, and subsonic auto-ignition deflagration can be sequentially observed with the increase of temperature gradient. However, affected by multiple hotspot interactions and pressure wave disturbance, deflagration to detonation transition arising from secondary hotspot auto -ignition becomes prevalent. It is noted that, unlike direct detonation that evolves at the entire circumfer-ential directions, deflagration to detonation transition develops only along certain directions with inter-mediate temperature gradient, and such gradient steepness is much higher than previous results based on simplified models. When turbulence fluctuation is introduced, the distribution of thermal stratification is modified significantly and the local temperature field is broken into multiple smaller regions filled with mixed temperature gradients. Consequently, deflagration to detonation transition is promoted both tem-porally and spatially, especially at high turbulence intensity. Besides, the SVM classifier is trained using the above results of numerical simulations for detonation predictions. A diagram consisting of the most energetic length scale and temperature fluctuation is proposed, which shows good performance in pre-dicting detonation occurrence. The present study demonstrates that thermal stratification and turbulent intensity can significantly affect the transition behavior of auto-ignition development mode, and machine learning approaches have the potential to achieve good predictions for detonation occurrence in multiple physical fields.(c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved. |
| WOS关键词 | DIRECT NUMERICAL-SIMULATION ; REACTION FRONT PROPAGATION ; N-HEPTANE/AIR MIXTURE ; DETONATION DEVELOPMENT ; TEMPERATURE INHOMOGENEITIES ; CONSTANT VOLUME ; AUTOIGNITION ; HCCI ; CLASSIFICATION ; DEFLAGRATION |
| 资助项目 | National Natural Science Foundation of China ; [52076149] ; [51825603] |
| WOS研究方向 | Thermodynamics ; Energy & Fuels ; Engineering |
| 语种 | 英语 |
| WOS记录号 | WOS:000896513300001 |
| 出版者 | ELSEVIER SCIENCE INC |
| 资助机构 | National Natural Science Foundation of China |
| 源URL | [http://ir.giec.ac.cn/handle/344007/38081]  |
| 专题 | 中国科学院广州能源研究所 |
| 通讯作者 | Wei, Haiqiao |
| 作者单位 | 1.Tianjin Univ, State Key Lab Engines, Tianjin 300072, Peoples R China 2.Chinese Acad Sci, Guangzhou Inst Energy Convers, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Pan, Jiaying,He, Yu,Wang, Lei,et al. Effects of thermal stratification and turbulent intensity on auto-ignition and combustion mode transition[J]. COMBUSTION AND FLAME,2022,244:16. |
| APA | Pan, Jiaying,He, Yu,Wang, Lei,Li, Tao,Wei, Haiqiao,&Shu, Gequn.(2022).Effects of thermal stratification and turbulent intensity on auto-ignition and combustion mode transition.COMBUSTION AND FLAME,244,16. |
| MLA | Pan, Jiaying,et al."Effects of thermal stratification and turbulent intensity on auto-ignition and combustion mode transition".COMBUSTION AND FLAME 244(2022):16. |
入库方式： OAI收割
来源：广州能源研究所
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