Fire Safety Journal最新文献_第8页

Toxicant production in under-ventilated compartment fires assessed by laser absorption spectroscopy 用激光吸收光谱法评估通风不足的隔间火灾中毒物的产生

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-08 DOI: 10.1016/j.firesaf.2025.104534

Rayna Vreeland , Kyle L. Fetter , Nicolas S.B. Jaeger , Yi Yan , Xiuqi Xi , James L. Urban , Daniel I. Pineda , R. Mitchell Spearrin

The production of incomplete combustion products from the burning of wood, medium density fiberboard (MDF), and nylon in an under-ventilated compartment fire was investigated using a reduced-scale compartment. Species measurements of carbon monoxide (CO) and carbon dioxide (CO₂) were performed using Fourier Transform Infrared Spectroscopy (FTIR) and methane (CH₄), hydrogen cyanide (HCN), benzene (C₆H₆), ethylene (C₂H₄) and acetylene (C₂H₂) were measured with Laser Absorption Spectroscopy (LAS) with three different interband cascade lasers. The fuels were burned in three different crib configurations; only wood, only MDF, and a mixture of wood and nylon, to examine the production of different toxicants. During the experiments, measurements were collected of CO, CO₂, CH₄, HCN, C₂H₂, and C₆H₆ species from the gas exiting the compartment, gas temperature from inside the compartment, and the flow into and out of the compartment. Consistent with under-ventilated combustion, the temperature inside the compartment typically exceeded 600 °C. CO was measured during all experiments and was two orders of magnitude less than the measured CO₂ concentration. Significant amounts of unburned hydrocarbons were measured during all of the experiments, while HCN was only detected during the wood-nylon tests. Higher toxicant yields were measured for wood-nylon compared to pure wood and MDF.

使用缩小尺寸的燃烧室研究了木材、中密度纤维板（MDF）和尼龙在通风不足的燃烧室中燃烧产生的不完全燃烧产物。采用傅里叶变换红外光谱法（FTIR）测量了一氧化碳（CO）和二氧化碳（CO2）的组分，采用激光吸收光谱法（LAS）测量了甲烷（CH4）、氰化氢（HCN）、苯（C6H6）、乙烯（C2H4）和乙炔（C2H2）的组分。燃料在三种不同的婴儿床结构中燃烧；只有木材，只有中密度纤维板，以及木材和尼龙的混合物，来检查不同的有毒物质的生产。在实验过程中，测量了出舱气体的CO、CO2、CH4、HCN、C2H2和C6H6，舱内气体温度以及进出舱内的流量。与不通风燃烧一致，燃烧室内的温度通常超过600°C。在所有实验中都测量了CO，其浓度比测量的CO2浓度小两个数量级。在所有实验中都测量了大量未燃烧的碳氢化合物，而HCN仅在木-尼龙测试中被检测到。与纯木材和中密度纤维板相比，木质尼龙的有毒物质产量更高。

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引用次数: 0

The effect of water vapor on the flammability of fluorinated refrigerants 水蒸气对含氟制冷剂可燃性的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-07 DOI: 10.1016/j.firesaf.2025.104553

Gregory T. Linteris , Michael J. Hegetschweiler , Valeri I. Babushok

Possible replacements for the refrigerant R-134a have been proposed in previous work based on their flammability behavior in standard tests of the Heating, Ventilation, Air-Conditioning, and Refrigeration industry. The present work extends that behavior to more extreme conditions of temperature and humidity based on estimates of the overall reaction rate of the mixtures obtained from perfectly-stirred reactor (PSR) model simulations. The PSR simulations were found to predict the flammability conditions of the standard test well. For initial temperatures of 23 °C–60 °C and water vapor volume fraction in the oxidizer of 0 %–10 %, the effect of humidity on the overall reaction rate is predicted to be much larger than the effect of temperature, with an increase in the overall reaction rate up to about 2.5–9 times with most moist flames as compared to dry.

基于R-134a在采暖、通风、空调和制冷行业的标准测试中的可燃性，在之前的工作中提出了制冷剂R-134a的可能替代品。目前的工作将这种行为扩展到更极端的温度和湿度条件下，基于从完全搅拌反应器（PSR）模型模拟中获得的混合物的总体反应速率估计。发现PSR模拟可以预测标准测试井的可燃性条件。当初始温度为23°C - 60°C，氧化剂中水蒸气体积分数为0% - 10%时，湿度对总反应速率的影响预计要比温度的影响大得多，与干燥火焰相比，大多数湿火焰的总反应速率可提高约2.5-9倍。

引用次数: 0

Modelling the probability of smouldering ignition of vegetation from hot metal particles ejected by power lines 模拟由电力线喷出的热金属颗粒引起植被阴燃的可能性

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-01 DOI: 10.1016/j.firesaf.2025.104537

Auriane Javaloyes, Alexander Castagna, Nikolaos Kalogeropoulos, Guillermo Rein

Power line failures can cause wildfires, particularly in regions like California, Australia, and Portugal, where high-wind conditions have led to the clash of power line conductors, ejecting metal particles that can ignite nearby vegetation. While ignition by particles has been the focus of experiments before, its modelling remains understudied. This paper presents a computational model to predict ignition by particles, focusing on smouldering as the critical stage before flaming. Particle trajectory and cooling in flight are simulated stochastically using equations of motion and heat transfer, while ignition of vegetation is modelled through a pseudo-one-dimensional thermochemical medium with Gpyro. Using weather and fuel data from California as a case study, results show that for wind speeds up to 20 m/s, aluminium particles with a diameter of at least 6.5 mm, ejected from a 20 m high power line, land at temperatures above 740 °C and can ignite grass and shrub fuel beds, creating an at-risk zone of 274 m

^{2}

around the conductor clash point, extending up to 52 m from the power line. Fuel moisture is the primary factor influencing ignition, followed by particle size. This modelling study contributes to close the gap in modelling ignition by particles and offers insights for mitigating wildfire hazards from power lines.

电力线故障可能引发野火，特别是在加利福尼亚、澳大利亚和葡萄牙等地区，在这些地区，强风条件导致电力线导体发生碰撞，喷出的金属颗粒可能点燃附近的植被。虽然粒子点火一直是以前实验的重点，但其模型研究仍不充分。本文提出了一种预测颗粒着火的计算模型，重点讨论了燃烧前的关键阶段阴燃。利用运动和传热方程对颗粒的飞行轨迹和冷却过程进行了随机模拟，同时利用Gpyro模拟了植被的引燃过程。以加利福尼亚州的天气和燃料数据为例进行研究，结果表明，当风速高达20米/秒时，直径至少为6.5毫米的铝颗粒从20米高的电力线中喷射出来，在740°C以上的温度下着陆，并可能点燃草和灌木燃料床，在导体碰撞点周围形成274平方米的危险区域，从电力线延伸至52米。影响着火的主要因素是燃料水分，其次是颗粒大小。该模型研究有助于缩小颗粒点火模型的差距，并为减轻电力线的野火危害提供见解。

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引用次数: 0

Influence of inert-gas dilution on flame extinction and spread over solid fuel in low velocity oxidizer flows 惰性气体稀释对低速氧化剂流动中火焰熄灭和在固体燃料上蔓延的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-30 DOI: 10.1016/j.firesaf.2025.104548

Feng Zhu , Sen Li , Shuangfeng Wang , Wenlong Wang , Yuhan Jiang

Physical or inert fire suppressants such as N₂, Ar, and CO₂ have been broadly used on earth, while CO₂ suppressant is now employed aboard human-crew spacecrafts where the atmospheric environment is characterized primarily by low-velocity oxidizer flow. Effects of inert diluent gases (N₂, Ar, He, CO₂) on flame spread and extinction behavior over thermally-thick solid fuel with low-velocity opposed oxidizer flow environment were studied by experiments and numerical simulation. With the same oxygen volume concentration and flow velocity, the flame propagates fastest when He is used as the diluted gas, while propagates slowest in O₂/CO₂ environment. Further study found that CO₂, which has a large heat capacity to decrease the flame temperature, reduces the flame spread through thermal effect, while He promotes flame spread rate through both thermal and transport effect. In O₂/He environment, the flame extinction behavior is dominated by the diffusion effect through the greatest thermal diffusion to increase the excessive radiative heat loss ratio. In O₂/CO₂, the oxygen concentration limit comes second, which is dominated by thermal effect. The flammability range is the largest in O₂/Ar. The simulation results show that in low-velocity flow environment, if the inert-gases can emit or absorb thermal radiation, the characteristic heat transfer length increases. However, the reabsorption of emitted radiation has small effects on flame spread. This study provides valuable data on flame dynamics in diluted gases and can help develop more effective and applicable fire extinguishing agent for manned spacecraft in microgravity.

物理或惰性灭火剂，如N2、Ar和CO2已在地球上广泛使用，而CO2灭火剂现在被用于载人航天器，其大气环境主要以低速氧化剂流为特征。采用实验和数值模拟相结合的方法，研究了惰性稀释气体（N2、Ar、He、CO2）对低速对氧化剂流动环境下热厚固体燃料上火焰蔓延和熄灭行为的影响。在氧气体积浓度和流速相同的情况下，以He作为稀释气体时火焰传播速度最快，而在O2/CO2环境中传播速度最慢。进一步研究发现，CO2具有较大的降低火焰温度的热容，通过热效应减少火焰的传播，而He通过热效应和输运效应促进火焰的传播速度。在O2/He环境下，火焰的熄灭行为以扩散效应为主，通过最大的热扩散增加了过量的辐射热损失比。在O2/CO2中，氧浓度极限次之，主要受热效应影响。在O2/Ar中可燃性范围最大。仿真结果表明，在低速流动环境下，如果惰性气体能够发射或吸收热辐射，则特征换热长度增大。然而，发射辐射的重吸收对火焰蔓延的影响很小。该研究提供了稀释气体中火焰动力学的宝贵数据，有助于开发更有效和适用于微重力载人航天器的灭火剂。

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引用次数: 0

DSM-based prediction of lateral-torsional failure of cold-formed steel lipped channel beams at elevated Temperatures: Influence of the constitutive model 基于dsm的冷弯型钢唇形槽钢高温侧扭破坏预测：本构模型的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-28 DOI: 10.1016/j.firesaf.2025.104547

Natan Sian das Neves , Alexandre Landesmann , Dinar Camotim

Recently, the authors investigated the post-buckling behaviour, strength and Direct Strength Method (DSM) design of cold-formed steel (CFS) single-span simply supported lipped channel beams failing in lateral-torsional (LT) modes at elevated temperatures (up to 800 °C), adopting the constitutive model prescribed in Part 1–2 of Eurocode 3. The main fruit of this investigation was the development of an efficient DSM-based design approach capable of predicting adequately the beam LT failure moments. Since the failure moments at elevated temperatures are obviously influenced by the temperature-dependent material model considered, it is important to assess how the failure moment prediction quality provided by the above DSM-based design approach is influenced by a change in the material model adopted − this paper aims precisely at reporting an investigation dealing with such a performance assessment for the particular case of the material model at elevated temperatures prescribed by the current Australian/New Zealand specification for cold-formed steel structures (AS/NZS 4600). Like in the previous investigation, a large set of CFS beams at elevated temperatures (up to 800 °C) are analysed, exhibiting (i) various cross-section dimensions and yield stresses, selected to cover wider LT slenderness ranges, (ii) two end support conditions, differing only in the end cross-section wall displacement/rotation and warping restraints (either fully free or fully prevented), and (iii) temperature-dependent steel material properties according with the model prescribed in AS/NZS 4600. The results presented and discussed, obtained through ABAQUS shell finite element (SFE) geometrically and material non-linear analyses including (critical-mode − LT) initial geometrical imperfections (GMNIA), consist of beam LT (i) post-buckling equilibrium paths and deformed configurations, and (ii) fairly extensive numerical failure moment data. These numerical failure moments, together with those available in the literature, are then used to show that the quality of their predictions provided by the recently developed DSM-based strength curves becomes inadequate due to the change in the temperature-dependent steel constitutive model adopted. However, it is also shown that such inadequacy can be removed by merely inserting a new parameter that takes into account the specific features of the AS/NZS 4600 CFS constitutive model. This means that the format of the recently developed DSM-based strength curves can be retained and should constitute a good starting point to search for an efficient general DSM-based design approach for CFS beams failing in LT modes at room and elevated temperatures.

最近，作者采用欧洲规范3第1-2部分规定的本构模型，研究了高温（高达800°C）下，冷弯钢（CFS）单跨简支唇形槽钢在侧向扭转（LT）模式下的失稳后屈曲行为、强度和直接强度法（DSM）设计。这项研究的主要成果是开发了一种有效的基于dsm的设计方法，能够充分预测梁的LT失效时刻。由于高温下的破坏矩明显受到所考虑的温度相关材料模型的影响，评估上述基于dsm的设计方法所提供的失效矩预测质量如何受到所采用的材料模型变化的影响是很重要的——本文的目的正是报告一项调查，该调查针对当前澳大利亚/新西兰冷弯钢结构规范（AS/NZS 4600）规定的高温下材料模型的特殊情况进行了这种性能评估。与之前的调查一样，对高温（高达800°C）下的大量CFS梁进行了分析，显示出(i)不同的横截面尺寸和屈服应力，选择覆盖更宽的LT长细范围，（ii）两种末端支撑条件，仅在端横截面壁位移/旋转和翘曲限制（完全自由或完全防止）方面有所不同。（iii）根据AS/NZS 4600中规定的模型，与温度相关的钢材料性能。通过ABAQUS壳体有限元（SFE）几何和材料非线性分析（包括（临界模式- LT）初始几何缺陷（GMNIA））获得的结果包括梁LT (i)屈曲后平衡路径和变形构型，以及（ii）相当广泛的数值破坏力矩数据。这些数值失效矩，连同文献中可用的失效矩，然后被用来表明，由于采用的温度相关钢本构模型的变化，由最近开发的基于dsm的强度曲线提供的预测质量变得不足。然而，也表明，这种不足可以通过仅仅插入一个考虑到AS/NZS 4600 CFS本构模型的具体特征的新参数来消除。这意味着最近开发的基于dsm的强度曲线的格式可以保留，并且应该构成一个良好的起点，以寻找一种有效的基于dsm的CFS梁在室温和高温下在LT模式下失效的通用设计方法。

{"title":"DSM-based prediction of lateral-torsional failure of cold-formed steel lipped channel beams at elevated Temperatures: Influence of the constitutive model","authors":"Natan Sian das Neves , Alexandre Landesmann , Dinar Camotim","doi":"10.1016/j.firesaf.2025.104547","DOIUrl":"10.1016/j.firesaf.2025.104547","url":null,"abstract":"<div><div>Recently, the authors investigated the post-buckling behaviour, strength and Direct Strength Method (DSM) design of cold-formed steel (CFS) single-span simply supported lipped channel beams failing in lateral-torsional (LT) modes at elevated temperatures (up to 800 °C), adopting the constitutive model prescribed in Part 1–2 of Eurocode 3. The main fruit of this investigation was the development of an efficient DSM-based design approach capable of predicting adequately the beam LT failure moments. Since the failure moments at elevated temperatures are obviously influenced by the temperature-dependent material model considered, it is important to assess how the failure moment prediction quality provided by the above DSM-based design approach is influenced by a change in the material model adopted − this paper aims precisely at reporting an investigation dealing with such a performance assessment for the particular case of the material model at elevated temperatures prescribed by the current Australian/New Zealand specification for cold-formed steel structures (AS/NZS 4600). Like in the previous investigation, a large set of CFS beams at elevated temperatures (up to 800 °C) are analysed, exhibiting (i) various cross-section dimensions and yield stresses, selected to cover wider LT slenderness ranges, (ii) two end support conditions, differing only in the end cross-section wall displacement/rotation and warping restraints (either fully free or fully prevented), and (iii) temperature-dependent steel material properties according with the model prescribed in AS/NZS 4600. The results presented and discussed, obtained through ABAQUS shell finite element (SFE) geometrically and material non-linear analyses including (critical-mode − LT) initial geometrical imperfections (GMNIA), consist of beam LT (i) post-buckling equilibrium paths and deformed configurations, and (ii) fairly extensive numerical failure moment data. These numerical failure moments, together with those available in the literature, are then used to show that the quality of their predictions provided by the recently developed DSM-based strength curves becomes inadequate due to the change in the temperature-dependent steel constitutive model adopted. However, it is also shown that such inadequacy can be removed by merely inserting a new parameter that takes into account the specific features of the AS/NZS 4600 CFS constitutive model. This means that the format of the recently developed DSM-based strength curves can be retained and should constitute a good starting point to search for an efficient general DSM-based design approach for CFS beams failing in LT modes at room and elevated temperatures.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104547"},"PeriodicalIF":3.3,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cracking quantification of wood exposed to constant heat fluxes 暴露在恒定热通量下的木材的开裂量化

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-26 DOI: 10.1016/j.firesaf.2025.104546

Boris Aguilar , Pedro Reszka , Zoubir Acem , Pascal Boulet , Gilles Parent , Lucas Terrei

Surface cracking of wood when exposed to a heat source is one of the factors understudied by the fire community despite the fact that the cracks may guide the release of pyrolysis gases, inducing heterogeneity in the effusion of gas and therefore may affect ignition and extinction of flame at the material surface. This study aimed to develop a dynamic detection method for characterizing wood cracking during fire tests by providing quantities such as surface area, length, and number of cracks. Spruce samples were exposed to a wide range of heat fluxes during for at least 40 min using a vertical cone calorimeter. An infrared camera with a specific filter wavelength was used to track crack formation. A total of 74 experiments were carried out in air, and seven were carried out in an oxygen-free atmosphere to determine the cracking dynamics of the wood. The results show that the cracking rate and the number of cracks quickly reach to a constant value. The heat flux and the presence of oxygen are not dominant factors in wood’s dynamic cracking. This work provides quantitative data for readers interested in accounting for cracking and heterogeneous pyrolysis gas release on the surface of a sample.

木材在热源下的表面开裂是火学界尚未研究的因素之一，尽管这些裂缝可能会引导热解气体的释放，导致气体渗出的非均质性，从而可能影响材料表面火焰的点燃和熄灭。本研究旨在开发一种动态检测方法，通过提供诸如表面面积、长度和裂纹数量等数量来表征木材在火灾试验中的开裂。云杉样品暴露在大范围的热通量至少40分钟期间使用垂直锥量热计。采用具有特定滤光波长的红外摄像机跟踪裂纹的形成。在空气中进行了74次实验，在无氧气氛中进行了7次实验，以确定木材的开裂动力学。结果表明，裂纹速率和裂纹数很快达到一个恒定值。热通量和氧的存在不是木材动态开裂的主导因素。这项工作为有兴趣的读者提供了定量数据，说明裂解和异质热解气体释放在一个样品的表面。

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引用次数: 0

Towards predictive engineering-type simulations of upward flame spread in SBI scenarios SBI情景下火焰向上蔓延的预测工程模拟

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-24 DOI: 10.1016/j.firesaf.2025.104544

G. Maragkos, A. Snegirev, J. At Thabari, Y. Moorthamers, B. Merci

Large eddy simulations of upward flame spread using FireFOAM are presented. Aiming at advancing predictive fire modelling, the approach considers the use of dynamic models, with limited use of model constants, for turbulence, combustion, and radiation. Modelling of convective heat transfer is based on Newton’s law of cooling considering simplified correlations for natural convection. The thermal decomposition of the solid material is represented through a 1D pyrolysis model with optimized model-effective material properties. For validation purposes, medium-scale Single Burning Item (SBI) experiments are used, involving both inert materials (calcium silicate) and flammable walls involving both charring (MDF and plywood) and non-charring (PMMA) materials. Separate validations for the gas and solid phase are also presented. A detailed comparison between the CFD predictions and experimental data is performed, focusing on global parameters (i.e., HRR, mass loss rate, heat feedback) and local quantities (i.e., total heat fluxes). The modelling approach performs very well, with predictions being fairly grid-insensitive, showing relative differences in the predicted HRR of up to 47% between the simulations and the experiments. Convection contributes up to 30% of the total wall heat feedback, highlighting the importance of accurately modelling convection alongside radiation in early flame spread.

利用FireFOAM进行了火焰向上蔓延的大涡流模拟。旨在推进预测火灾建模，该方法考虑使用动态模型，有限地使用模型常数，湍流，燃烧和辐射。对流换热的建模基于牛顿冷却定律，考虑了自然对流的简化关联。固体材料的热分解通过一维热解模型表示，模型有效材料性能优化。为了验证目的，使用了中等规模的单一燃烧项目（SBI）实验，涉及惰性材料（硅酸钙）和易燃壁，涉及炭化（中密度纤维板和胶合板）和非炭化（PMMA）材料。还分别对气相和固相进行了验证。将CFD预测与实验数据进行了详细的比较，重点关注全局参数（即HRR、质量损失率、热反馈）和局部量（即总热流密度）。建模方法表现得非常好，预测对网格不敏感，在模拟和实验之间显示出预测HRR的相对差异高达47%。对流贡献了高达30%的总壁面热反馈，突出了在早期火焰传播中准确模拟对流和辐射的重要性。

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引用次数: 0

Thresholds of surface fire transition to crown fire: Effects of wind speed and crown base height with fixed moisture content 地表火向树冠火过渡的阈值：固定含水率下风速和树冠底高的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-22 DOI: 10.1016/j.firesaf.2025.104545

Mohamed Sharaf , Duncan Sutherland , Rahul Wadhwani , Khalid Moinuddin

Forest fires present significant global risks, leading to loss of life, community displacement, and extensive damage to property and the environment, with substantial economic and social consequences. Propagation of wildland fires can be divided into two categories: surface and crown fires. This study aims to identify threshold parameters that influence the transition from surface to crown fire, helping fire managers prevent manageable fires from escalating into uncontrollable crown fires. This study conducted pine forest simulations using the physics-based fire model Fire Dynamics Simulator (FDS) to examine the effects of varying wind speeds and crown base heights on fire transition. The results identify that 80 % crown mass loss represents sustained crowning, while values between 65 % and 80 % correspond to intermediate crowning. Furthermore, the findings demonstrate that wind speed and crown base height are crucial in reaching these threshold values. A reduction in crown base height substantially increases the likelihood of sustained crowning. However, the influence of wind speed on the surface fire transition varies with crown base height. These findings enhance understanding of surface fire transition and offer valuable insights for forest fire management and prevention.

森林火灾带来了重大的全球风险，导致生命损失、社区流离失所，并对财产和环境造成广泛破坏，造成严重的经济和社会后果。野火的传播可分为两类：地表火和树冠火。本研究旨在确定影响从地表火灾到树冠火灾过渡的阈值参数，帮助火灾管理者防止可控火灾升级为不可控的树冠火灾。本研究利用基于物理的火灾模型fire Dynamics Simulator （FDS）对松林进行模拟，研究不同风速和树冠基部高度对火灾过渡的影响。结果表明，冠层质量损失80%为持续冠层，65% ~ 80%为中间冠层。此外，研究结果表明，风速和冠底高度是达到这些阈值的关键。冠底高度的降低大大增加了持续冠的可能性。风速对地表火过渡的影响随树冠基部高度的变化而变化。这些发现增强了对地表火过渡的认识，并为森林火灾管理和预防提供了有价值的见解。

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引用次数: 0

Experimental study of fire propagation along a vertical wall in a lab scale setup 火灾沿垂直墙体传播的实验研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-19 DOI: 10.1016/j.firesaf.2025.104540

F. Di Giorgio, C. Galizzi, M. Kühni

A characterization study was conducted on a novel experimental setup designed to investigate the spread of façade fires. This setup consists of a wall divided into an effusion zone, where methane injection simulates the pyrolysis process, and a large inert zone where the flame propagates. Various flow rates were applied to the effusion module and analyzed through direct visualizations, CH* and OH* chemiluminescence imaging, as well as temperature and heat flux. The results highlight and confirm the well-established influence of fuel injection rates on flame behavior and propagation. This standardized configuration serves as a benchmark for comparisons with more complex scenarios involving different arrangements of effusion and inert zones. Moreover, the data generated in this study provide a valuable basis for evaluating the reliability of fire engineering models and codes.

一项表征研究进行了一种新的实验设置，旨在调查农林业火灾的蔓延。该装置由一堵墙组成，墙分为渗出区（甲烷注入模拟热解过程）和一个大的惰性区（火焰传播）。通过直接可视化、CH*和OH*化学发光成像以及温度和热流密度对积液模块施加不同的流量进行分析。结果强调并证实了燃油喷射速率对火焰行为和传播的影响。这种标准化的配置可以作为比较涉及不同积液区和惰性区安排的更复杂场景的基准。此外，本研究产生的数据为评估消防工程模型和规范的可靠性提供了有价值的依据。

引用次数: 0

Downward opposed flame spread response to non-steady airflow 非定常气流下的反向火焰蔓延响应

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-09-17 DOI: 10.1016/j.firesaf.2025.104543

Alana Miska , Pablo E. Pinto , Xiuqi Xi , Maria Thomsen , James L. Urban

PMMA is burned in a bench-scale wind tunnel under steady and oscillating airflows to characterize the downward flame spread response to non-steady airflow conditions. An opposed forced flow configuration is used with 0.5 and 1 mm thick black cast PMMA. The non-steady airflow oscillations for both PMMA thicknesses take the form of a transient sinusoidal profile with three amplitudes (0.1, 0.15 and 0.2 m/s), three frequencies (1/8, 1/16 and 1/32 Hz) and one baseline airflow (0.45 m/s). The time averaged and transient flame spread rate are measured using the change in pyrolysis front over time. The frequency response of the flame behavior, flame length and flame spread rate due to the impact of the non-steady airflow are investigated. A transient gas phase response is seen in all forced flow conditions. The smaller sample thickness displayed a clearer response in the transient flame spread to the non-steady airflow. This behavior is analyzed using physical timescales for solid-phase heating.

在稳定气流和振荡气流条件下，PMMA在实验风洞中燃烧，以表征非稳定气流条件下火焰向下蔓延的响应。一个反对的强制流动配置使用0.5和1毫米厚的黑色铸造PMMA。两种PMMA厚度的非稳定气流振荡都采用瞬态正弦曲线的形式，具有三个振幅（0.1,0.15和0.2 m/s），三个频率（1/ 8,1 /16和1/32 Hz）和一个基线气流（0.45 m/s）。利用热解前沿随时间的变化，测量了平均时间和瞬态火焰蔓延速率。研究了非定常气流对火焰特性、火焰长度和火焰蔓延速率的频率响应。在所有强制流动条件下都可以看到瞬态气相响应。试样厚度越小，火焰向非稳态气流的瞬态传播响应越明显。使用固相加热的物理时间尺度分析了这种行为。

引用次数: 0