Numerical Study on Pilot Ignition of a Thermally-Thick Solid Fuel with Low-Velocity Airflow in Microgravity
文献类型：期刊论文
| 作者 | Zhang K(张凯)1,2; Zhu F(朱凤)2 ; Wang SF(王双峰)1,2
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| 刊名 | MICROGRAVITY SCIENCE AND TECHNOLOGY
 |
| 出版日期 | 2023-12-29 |
| 卷号 | 36期号:1页码:12 |
| ISSN号 | 0938-0108 |
| 关键词 | Ignition Solid material Low-velocity flow Microgravity Critical mass flux |
| DOI | 10.1007/s12217-023-10092-7 |
| 通讯作者 | Zhu, Feng(zhufeng@imech.ac.cn) |
| 英文摘要 | The mechanisms controlling the dependence on low-velocity flow of the piloted ignition of a solid material under external radiant heating is investigated through a numerical modeling. The poly (methyl methacrylate) (PMMA) was used as the fuel. The objective of the present study is to gain insight into the intrinsic ignition mechanisms of a solid fuel, as well as to gain a more comprehensive understanding of the dynamical characteristics of the ignition process near the extinction limit. For this purpose, a two-dimensional numerical model has been developed using the Fire Dynamic Simulator (FDS5) code, in which both solid-phase and gas-phase reactions are calculated. Two radiant heat flux, which are 16 and 25 kW/m2 were studied, and an external air flow was varied from 3 to 40 cm/s. The simulation results showed that transient gas reaction flashed before a continuous flame was attached to the sample surface for gas flow velocities lower than a critical value. As the flow velocity is reduced, the flashing time, which is defined as the time when any flame is seen above the sample surface, decreases, while the duration of flashing increases. The solid surface temperature and mass flow rate increase rapidly during flashing. The ignition time, which is defined as the time when a continuous flame is attached to the fuel surface, decreases, reaches a minimum, and then increases until ignition cannot occur. Mechanisms were considered to explain the ''V-shaped" dependence of ignition time on flow-velocity, and two regimes were identified each having a different controlling mechanism: the mass transport regime where the ignition delay is controlled by the mixing of oxygen and pyrolyzate; and the heat transfer regime where the ignition delay is controlled by changes in convection heat losses and critical mass flux for ignition. With the decrease of the airflow velocity, the critical mass flux shows a trend of decreasing and then increasing, which is dominated by the mixing of the pyrolyzate and the oxidizer, while the critical temperature monotonically decreases, which is dominated by a reduction of the net heat flux at the fuel surface. The results provide further insight into the ignition behavior of solid fuel under low-velocity flow environment, and guidance about fire safety in microgravity environments. |
| 分类号 | 二类 |
| WOS关键词 | FLAME SPREAD ; DELAY |
| 资助项目 | Young Elite Scientists Sponsorship Program by BAST |
| WOS研究方向 | Engineering ; Thermodynamics ; Mechanics |
| 语种 | 英语 |
| WOS记录号 | WOS:001131772800001 |
| 资助机构 | Young Elite Scientists Sponsorship Program by BAST |
| 其他责任者 | Zhu, Feng |
| 源URL | [http://dspace.imech.ac.cn/handle/311007/93982]  |
| 专题 | 力学研究所_国家微重力实验室 |
| 作者单位 | 1.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Key Lab Micrograv, Inst Mech, Beijing 100190, Peoples R China; |
| 推荐引用方式 GB/T 7714 | Zhang K,Zhu F,Wang SF. Numerical Study on Pilot Ignition of a Thermally-Thick Solid Fuel with Low-Velocity Airflow in Microgravity[J]. MICROGRAVITY SCIENCE AND TECHNOLOGY,2023,36(1):12. |
| APA | 张凯,朱凤,&王双峰.(2023).Numerical Study on Pilot Ignition of a Thermally-Thick Solid Fuel with Low-Velocity Airflow in Microgravity.MICROGRAVITY SCIENCE AND TECHNOLOGY,36(1),12. |
| MLA | 张凯,et al."Numerical Study on Pilot Ignition of a Thermally-Thick Solid Fuel with Low-Velocity Airflow in Microgravity".MICROGRAVITY SCIENCE AND TECHNOLOGY 36.1(2023):12. |
入库方式： OAI收割
来源：力学研究所
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