Luca Carmignani, Mohammadhadi Hajilou, Jeanette Cobian-Iñiguez, Mark Finney, Scott L. Stephens, Michael J. Gollner, Carlos Fernandez-Pello
{"title":"木材燃烧:风和燃料几何形状的影响","authors":"Luca Carmignani, Mohammadhadi Hajilou, Jeanette Cobian-Iñiguez, Mark Finney, Scott L. Stephens, Michael J. Gollner, Carlos Fernandez-Pello","doi":"10.1007/s10694-024-01542-8","DOIUrl":null,"url":null,"abstract":"<p>Large and downed woody fuels remaining behind a wildfire’s flame front tend to burn in a smoldering regime, producing large quantities of toxic gases and particulate emissions, which deteriorates air quality and compromises human health. Smoldering burning rates are affected by fuel type and size, the amount of oxygen reaching the surface, and heat losses to the surroundings. An external wind has the dual effects of bringing fresh oxidizer to the fuel surface and porous interior, while at the same time enhancing convective cooling. In this work, a series of experiments were conducted on single and adjacent poplar dowels to investigate the effect of fuel geometry and wind speed on smoldering of woody fuels, including its burning rate and combustion products. Dowels had variable thickness (19.1 and 25.4 mm), aspect ratios, and arrangement (number of dowels and spacing between them). Using measurement of mass loss, CO, and HC production as indicators of the smoldering intensity, the results indicate that the arrangement of smoldering objects significantly affects burning rates and emissions. Specifically, spacings of 1/8 and 1/4 of the dowel thickness enhanced the smoldering process. The smoldering intensity was also enhanced by increased external wind (ranging between 0.3 m/s and 1.5 m/s), but its effect was dependent upon the spacing between the dowels. The convective losses associated with the spacing were further investigated with a simplified computational model. The simulations show that the wind significantly increases convective losses from the smoldering surfaces, which in turn may offset the increase in smoldering intensity related to the higher oxygen flux at higher wind speeds.</p>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Smoldering of Wood: Effects of Wind and Fuel Geometry\",\"authors\":\"Luca Carmignani, Mohammadhadi Hajilou, Jeanette Cobian-Iñiguez, Mark Finney, Scott L. Stephens, Michael J. Gollner, Carlos Fernandez-Pello\",\"doi\":\"10.1007/s10694-024-01542-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Large and downed woody fuels remaining behind a wildfire’s flame front tend to burn in a smoldering regime, producing large quantities of toxic gases and particulate emissions, which deteriorates air quality and compromises human health. Smoldering burning rates are affected by fuel type and size, the amount of oxygen reaching the surface, and heat losses to the surroundings. An external wind has the dual effects of bringing fresh oxidizer to the fuel surface and porous interior, while at the same time enhancing convective cooling. In this work, a series of experiments were conducted on single and adjacent poplar dowels to investigate the effect of fuel geometry and wind speed on smoldering of woody fuels, including its burning rate and combustion products. Dowels had variable thickness (19.1 and 25.4 mm), aspect ratios, and arrangement (number of dowels and spacing between them). Using measurement of mass loss, CO, and HC production as indicators of the smoldering intensity, the results indicate that the arrangement of smoldering objects significantly affects burning rates and emissions. Specifically, spacings of 1/8 and 1/4 of the dowel thickness enhanced the smoldering process. The smoldering intensity was also enhanced by increased external wind (ranging between 0.3 m/s and 1.5 m/s), but its effect was dependent upon the spacing between the dowels. The convective losses associated with the spacing were further investigated with a simplified computational model. The simulations show that the wind significantly increases convective losses from the smoldering surfaces, which in turn may offset the increase in smoldering intensity related to the higher oxygen flux at higher wind speeds.</p>\",\"PeriodicalId\":558,\"journal\":{\"name\":\"Fire Technology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2024-02-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Fire Technology\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://doi.org/10.1007/s10694-024-01542-8\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Fire Technology","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s10694-024-01542-8","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}
Smoldering of Wood: Effects of Wind and Fuel Geometry
Large and downed woody fuels remaining behind a wildfire’s flame front tend to burn in a smoldering regime, producing large quantities of toxic gases and particulate emissions, which deteriorates air quality and compromises human health. Smoldering burning rates are affected by fuel type and size, the amount of oxygen reaching the surface, and heat losses to the surroundings. An external wind has the dual effects of bringing fresh oxidizer to the fuel surface and porous interior, while at the same time enhancing convective cooling. In this work, a series of experiments were conducted on single and adjacent poplar dowels to investigate the effect of fuel geometry and wind speed on smoldering of woody fuels, including its burning rate and combustion products. Dowels had variable thickness (19.1 and 25.4 mm), aspect ratios, and arrangement (number of dowels and spacing between them). Using measurement of mass loss, CO, and HC production as indicators of the smoldering intensity, the results indicate that the arrangement of smoldering objects significantly affects burning rates and emissions. Specifically, spacings of 1/8 and 1/4 of the dowel thickness enhanced the smoldering process. The smoldering intensity was also enhanced by increased external wind (ranging between 0.3 m/s and 1.5 m/s), but its effect was dependent upon the spacing between the dowels. The convective losses associated with the spacing were further investigated with a simplified computational model. The simulations show that the wind significantly increases convective losses from the smoldering surfaces, which in turn may offset the increase in smoldering intensity related to the higher oxygen flux at higher wind speeds.
期刊介绍:
Fire Technology publishes original contributions, both theoretical and empirical, that contribute to the solution of problems in fire safety science and engineering. It is the leading journal in the field, publishing applied research dealing with the full range of actual and potential fire hazards facing humans and the environment. It covers the entire domain of fire safety science and engineering problems relevant in industrial, operational, cultural, and environmental applications, including modeling, testing, detection, suppression, human behavior, wildfires, structures, and risk analysis.
The aim of Fire Technology is to push forward the frontiers of knowledge and technology by encouraging interdisciplinary communication of significant technical developments in fire protection and subjects of scientific interest to the fire protection community at large.
It is published in conjunction with the National Fire Protection Association (NFPA) and the Society of Fire Protection Engineers (SFPE). The mission of NFPA is to help save lives and reduce loss with information, knowledge, and passion. The mission of SFPE is advancing the science and practice of fire protection engineering internationally.