封闭对微重力条件下纤维素和聚合物固体上对置流火焰蔓延的影响

IF 1.3 4区 工程技术 Q2 ENGINEERING, AEROSPACE
Ankit Sharma, Yanjun Li, Ya-Ting T. Liao, Paul V. Ferkul, Michael C. Johnston, Charles Bunnell
{"title":"封闭对微重力条件下纤维素和聚合物固体上对置流火焰蔓延的影响","authors":"Ankit Sharma,&nbsp;Yanjun Li,&nbsp;Ya-Ting T. Liao,&nbsp;Paul V. Ferkul,&nbsp;Michael C. Johnston,&nbsp;Charles Bunnell","doi":"10.1007/s12217-024-10106-y","DOIUrl":null,"url":null,"abstract":"<div><p>Opposed-flow flame spread over solid materials has been investigated in the past few decades owing to its importance in fundamental understanding of fires. These studies provided insights on the behavior of opposed-flow flames in different environmental conditions (e.g., flow speed, oxygen concentration). However, the effect of confinement on opposed-flow flames remains under-explored. It is known that confinement plays a critical role in concurrent-flow flame spread in normal and microgravity conditions. Hence, for a complete understanding it becomes important to understand the effects of confinement for opposed-flow flames. In this study, microgravity experiments are conducted aboard the International Space Station (ISS) to investigate opposed-flow flame spread in different confined conditions. Two materials, cotton-fiberglass blended textile fabric (SIBAL) and 1 mm thick polymethyl methacrylate (PMMA) slab are burned between a pair of parallel flow baffles in a small flow duct. By varying the sample-baffle distance, various levels of confinement are achieved (H = 1–2 cm). Three types of baffles, transparent, black, and reflective, are used to create different radiative boundary conditions. The purely forced flow speed is also varied (between 2.6 and 10.5 cm/s) to investigate its interplay with the confinement level. For both sample materials, it is observed that the flame spread rate decreases when the confinement level increases (i.e., when H decreases). In addition, flame spread rate is shown to have a positive correlation with flow speed, up to an optimal value. The results also indicate that the optimal flow speed for flame spread can decrease in highly confined conditions. Surface radiation on the confinement boundary is shown to play a key role. For SIBAL fabric, stronger flames are observed when using black baffles compared to transparent. For PMMA, reflective baffles yield stronger flames compared to black baffles. When comparing the results to the concurrent-flow case, it is also noticed that opposed-flow flames spread slower and blow off at larger flow speeds but are not as sensitive to the flow speed. This work provides unique long-duration microgravity experimental data that can inform the design of future opposed-flow experiments in microgravity and the development of theory and numerical models.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 2","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12217-024-10106-y.pdf","citationCount":"0","resultStr":"{\"title\":\"Effects of Confinement on Opposed-Flow Flame Spread over Cellulose and Polymeric Solids in Microgravity\",\"authors\":\"Ankit Sharma,&nbsp;Yanjun Li,&nbsp;Ya-Ting T. Liao,&nbsp;Paul V. Ferkul,&nbsp;Michael C. Johnston,&nbsp;Charles Bunnell\",\"doi\":\"10.1007/s12217-024-10106-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Opposed-flow flame spread over solid materials has been investigated in the past few decades owing to its importance in fundamental understanding of fires. These studies provided insights on the behavior of opposed-flow flames in different environmental conditions (e.g., flow speed, oxygen concentration). However, the effect of confinement on opposed-flow flames remains under-explored. It is known that confinement plays a critical role in concurrent-flow flame spread in normal and microgravity conditions. Hence, for a complete understanding it becomes important to understand the effects of confinement for opposed-flow flames. In this study, microgravity experiments are conducted aboard the International Space Station (ISS) to investigate opposed-flow flame spread in different confined conditions. Two materials, cotton-fiberglass blended textile fabric (SIBAL) and 1 mm thick polymethyl methacrylate (PMMA) slab are burned between a pair of parallel flow baffles in a small flow duct. By varying the sample-baffle distance, various levels of confinement are achieved (H = 1–2 cm). Three types of baffles, transparent, black, and reflective, are used to create different radiative boundary conditions. The purely forced flow speed is also varied (between 2.6 and 10.5 cm/s) to investigate its interplay with the confinement level. For both sample materials, it is observed that the flame spread rate decreases when the confinement level increases (i.e., when H decreases). In addition, flame spread rate is shown to have a positive correlation with flow speed, up to an optimal value. The results also indicate that the optimal flow speed for flame spread can decrease in highly confined conditions. Surface radiation on the confinement boundary is shown to play a key role. For SIBAL fabric, stronger flames are observed when using black baffles compared to transparent. For PMMA, reflective baffles yield stronger flames compared to black baffles. When comparing the results to the concurrent-flow case, it is also noticed that opposed-flow flames spread slower and blow off at larger flow speeds but are not as sensitive to the flow speed. This work provides unique long-duration microgravity experimental data that can inform the design of future opposed-flow experiments in microgravity and the development of theory and numerical models.</p></div>\",\"PeriodicalId\":707,\"journal\":{\"name\":\"Microgravity Science and Technology\",\"volume\":\"36 2\",\"pages\":\"\"},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2024-04-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s12217-024-10106-y.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microgravity Science and Technology\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12217-024-10106-y\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, AEROSPACE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microgravity Science and Technology","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s12217-024-10106-y","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, AEROSPACE","Score":null,"Total":0}
引用次数: 0

摘要

摘要 在过去的几十年里,人们一直在研究固体材料上的对流式火焰蔓延,因为这对从根本上了解火灾具有重要意义。这些研究提供了在不同环境条件(如流速、氧气浓度)下对流式火焰行为的见解。然而,封闭对对流式火焰的影响仍未得到充分探讨。众所周知,在正常和微重力条件下,束缚对并流火焰的扩散起着至关重要的作用。因此,要全面了解对流火焰的限制效应就变得非常重要。本研究在国际空间站(ISS)上进行了微重力实验,以研究不同封闭条件下的对流式火焰蔓延。两种材料,即棉纤维玻璃纤维混纺织物(SIBAL)和 1 毫米厚的聚甲基丙烯酸甲酯(PMMA)板,在一个小型流动管道中的一对平行挡板之间燃烧。通过改变样品与挡板的距离,可实现不同程度的封闭(H = 1-2 厘米)。透明、黑色和反射式三种类型的障板用于创造不同的辐射边界条件。此外,还改变了纯强制流速(2.6 厘米/秒至 10.5 厘米/秒),以研究其与封闭水平的相互作用。对于这两种样品材料,可以观察到当约束水平增加时(即 H 减小时),火焰蔓延率降低。此外,火焰蔓延率与流速呈正相关,直至达到一个最佳值。结果还表明,在高度密闭条件下,火焰传播的最佳流速会降低。密闭边界上的表面辐射起到了关键作用。对于 SIBAL 织物,与透明挡板相比,使用黑色挡板可观察到更强的火焰。对于 PMMA,与黑色障板相比,反射障板产生的火焰更强。在将结果与并流情况进行比较时,还注意到对流式火焰的扩散速度较慢,在流速较大时会被吹灭,但对流速的敏感性并不高。这项工作提供了独特的长时间微重力实验数据,可为未来微重力对流实验的设计以及理论和数值模型的开发提供参考。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Effects of Confinement on Opposed-Flow Flame Spread over Cellulose and Polymeric Solids in Microgravity

Opposed-flow flame spread over solid materials has been investigated in the past few decades owing to its importance in fundamental understanding of fires. These studies provided insights on the behavior of opposed-flow flames in different environmental conditions (e.g., flow speed, oxygen concentration). However, the effect of confinement on opposed-flow flames remains under-explored. It is known that confinement plays a critical role in concurrent-flow flame spread in normal and microgravity conditions. Hence, for a complete understanding it becomes important to understand the effects of confinement for opposed-flow flames. In this study, microgravity experiments are conducted aboard the International Space Station (ISS) to investigate opposed-flow flame spread in different confined conditions. Two materials, cotton-fiberglass blended textile fabric (SIBAL) and 1 mm thick polymethyl methacrylate (PMMA) slab are burned between a pair of parallel flow baffles in a small flow duct. By varying the sample-baffle distance, various levels of confinement are achieved (H = 1–2 cm). Three types of baffles, transparent, black, and reflective, are used to create different radiative boundary conditions. The purely forced flow speed is also varied (between 2.6 and 10.5 cm/s) to investigate its interplay with the confinement level. For both sample materials, it is observed that the flame spread rate decreases when the confinement level increases (i.e., when H decreases). In addition, flame spread rate is shown to have a positive correlation with flow speed, up to an optimal value. The results also indicate that the optimal flow speed for flame spread can decrease in highly confined conditions. Surface radiation on the confinement boundary is shown to play a key role. For SIBAL fabric, stronger flames are observed when using black baffles compared to transparent. For PMMA, reflective baffles yield stronger flames compared to black baffles. When comparing the results to the concurrent-flow case, it is also noticed that opposed-flow flames spread slower and blow off at larger flow speeds but are not as sensitive to the flow speed. This work provides unique long-duration microgravity experimental data that can inform the design of future opposed-flow experiments in microgravity and the development of theory and numerical models.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
Microgravity Science and Technology
Microgravity Science and Technology 工程技术-工程:宇航
CiteScore
3.50
自引率
44.40%
发文量
96
期刊介绍: Microgravity Science and Technology – An International Journal for Microgravity and Space Exploration Related Research is a is a peer-reviewed scientific journal concerned with all topics, experimental as well as theoretical, related to research carried out under conditions of altered gravity. Microgravity Science and Technology publishes papers dealing with studies performed on and prepared for platforms that provide real microgravity conditions (such as drop towers, parabolic flights, sounding rockets, reentry capsules and orbiting platforms), and on ground-based facilities aiming to simulate microgravity conditions on earth (such as levitrons, clinostats, random positioning machines, bed rest facilities, and micro-scale or neutral buoyancy facilities) or providing artificial gravity conditions (such as centrifuges). Data from preparatory tests, hardware and instrumentation developments, lessons learnt as well as theoretical gravity-related considerations are welcome. Included science disciplines with gravity-related topics are: − materials science − fluid mechanics − process engineering − physics − chemistry − heat and mass transfer − gravitational biology − radiation biology − exobiology and astrobiology − human physiology
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信