Experimental study on diffusive solid combustion behavior during transition from normal- to reduced-gravity | |
Hu LH; Delichatsios MA; Li J; Zhang XL; Wang SF(王双峰); Huo R; Hu, LH; Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China. | |
Source Publication | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER |
2012-03-01 | |
Volume | 55Issue:7-8Pages:2035-2043 |
ISSN | 0017-9310 |
Abstract | Experiments are carried out in a simplified drop system, which can provide a 2.3 s 10(-2) g reduced gravity period, to investigate the transition of solid material combustion behavior from normal- to reduced-gravity. A CCD camera records the diffusion flames produced by a solid fuel, Methenamine (C6H12N4), which easily sublimes and decomposes to flammable CH4 and H-2. The temperature distribution within the flame is analyzed by a monochromatic line of sight CCD measurement calibrated by a thermocouple measurement. It is revealed that during the transition period from normal- to reduced-gravity, the change of the flame shape, from tall and thin (pear like) to spherical, is faster than that of the luminance which represents the radiation intensity, indicating a relatively shorter adjustment time scale of dynamical gas flow buoyancy than that of the heat transfer when subjected to such a sudden change of gravity condition. It is also found that owing to the change of the flow affecting the oxygen and heat supply, the luminance of the flame as well as the burning rate, which was deduced based on projected area of the solid fuel according to d(2)-law, first decreases followed by an increment near the end of the drop where the gravity level slightly increases. The flame temperature gradually decreases, as the flame suddenly goes into reduced-gravity. Interpretation based on analysis of heat transfer balance and pyrolysis rate as well as the experimental results both indicate that the transitional effect is less pronounced for a smaller fuel particle than for a larger one, where buoyancy is stronger under normal-gravity whereas the flame has a larger standoff distance with increasing importance of the radiation losses from the fuel particle surface under reduced-gravity. The present work is relevant in assessing fire hazards of solid material during space travel as gravity levels change. |
Keyword | Reduced-gravity Combustion Of Solid Particles Transition From Normal To Reduced Gravity Luminance Droplet Combustion Microgravity Experiments Flame Extinction |
Subject Area | 微重力流体力学 |
URL | 查看原文 |
Indexed By | SCI ; EI |
Language | 英语 |
WOS ID | WOS:000300967600024 |
Funding Organization | This work is supported by Natural Science Foundation of China (NSFC) under Grant No. 51176180, Fundamental Research Funds for the Central Universities, Program for New Century Excellent Talents in University under Grant No. NCET-09-0914 and Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences. Prof. Michael Delichatsios was supported to be involved into this work by Chinese Academy of Science Visiting Professorship for Senior International Scientists under Grant No. 2009Z2-30. |
Department | NML微重力两相流与燃烧 |
Classification | 一类 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/46559 |
Collection | 微重力重点实验室 |
Corresponding Author | Hu, LH; Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China. |
Recommended Citation GB/T 7714 | Hu LH,Delichatsios MA,Li J,et al. Experimental study on diffusive solid combustion behavior during transition from normal- to reduced-gravity[J]. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,2012,55,7-8,:2035-2043. |
APA | Hu LH.,Delichatsios MA.,Li J.,Zhang XL.,王双峰.,...&Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China..(2012).Experimental study on diffusive solid combustion behavior during transition from normal- to reduced-gravity.INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,55(7-8),2035-2043. |
MLA | Hu LH,et al."Experimental study on diffusive solid combustion behavior during transition from normal- to reduced-gravity".INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 55.7-8(2012):2035-2043. |
Files in This Item: | Download All | |||||
File Name/Size | DocType | Version | Access | License | ||
SCI-J2012-075.pdf(1392KB) | 开放获取 | -- | View Download |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment