Fire Safety Journal最新文献_第4页

Corrigendum to “An experimental and numerical study of fire and plume characteristics of pool fires fueled by diesel-canola oil mixture” [Fire Saf. J., 159 (2026), 104560] “柴油-菜籽油混合燃料池火和羽流特性的实验和数值研究”[消防安全]的勘误表。[J] .中国生物医学工程学报，2009,32 (1),344 - 344]

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-14 DOI: 10.1016/j.firesaf.2025.104592

Navya Muniraj , Weixuan Gong , Muthu Kumaran Selvaraj , William Ruddy Mell , Albert Simeoni

引用次数: 0

Thermal response of hybrid steel-timber floor cross-sections exposed to standard fire: experimental and numerical investigations 暴露在标准火灾下的混合钢-木材地板截面的热响应：实验和数值研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-12 DOI: 10.1016/j.firesaf.2025.104593

Deonisius P. Aprisa , Ankit Agrawal , Ana Sauca , Ian Pope , Renaud Blondeau-Pâtissier , Luke Bisby , Martyn S. McLaggan

Hybrid systems that combine steel beams with cross-laminated timber (CLT) floor slabs can be vulnerable to fire, given the combustible nature of timber. Specifically, when unprotected, heat from a fire can conduct through steel beams to the CLT panels, which in turn may experience loss of mechanical properties, and possible charring (and combustion) in the connection zone between the CLT panel and the steel beam. Accordingly, this paper aims to establish thermal profiles in hybrid steel-timber floor cross-sections exposed to fire through experimental and numerical investigations. Results from fire tests and numerical validation studies on hybrid cross-sections exposed to a standard fire are presented; a total of six experiments with unprotected, partially protected, and fully protected steel sections were conducted following an ISO 834-1 standard fire exposure. Furthermore, a two-dimensional numerical heat transfer model was developed using SAFIR software, to predict the evolution of temperatures in the hybrid cross-section. The results confirm that passive fire protection of the steelwork using intumescent coatings plays a key role in determining the extent of charring in the connection region between the CLT panel and the steel section. In addition, temperature predictions from the developed numerical model show reasonable agreement with the experimental measurements.

考虑到木材的可燃性，结合钢梁和交叉层压木材（CLT）楼板的混合系统容易受到火灾的影响。具体来说，当不受保护时，来自火灾的热量可以通过钢梁传导到CLT板，而CLT板反过来可能会失去机械性能，并可能在CLT板和钢梁之间的连接区域发生炭化（和燃烧）。因此，本文旨在通过实验和数值研究建立钢-木混合地板在火灾下的截面热分布。从火测试结果和数值验证研究的混合截面暴露在一个标准的火；按照ISO 834-1标准进行了六次无保护、部分保护和完全保护钢截面的实验。此外，利用SAFIR软件建立了二维数值传热模型，预测了混合截面内温度的演变。结果表明，膨胀涂层对钢结构的被动防火是决定CLT板与钢截面连接区域炭化程度的关键。此外，所建立的数值模型的温度预测结果与实验测量结果吻合较好。

{"title":"Thermal response of hybrid steel-timber floor cross-sections exposed to standard fire: experimental and numerical investigations","authors":"Deonisius P. Aprisa , Ankit Agrawal , Ana Sauca , Ian Pope , Renaud Blondeau-Pâtissier , Luke Bisby , Martyn S. McLaggan","doi":"10.1016/j.firesaf.2025.104593","DOIUrl":"10.1016/j.firesaf.2025.104593","url":null,"abstract":"<div><div>Hybrid systems that combine steel beams with cross-laminated timber (CLT) floor slabs can be vulnerable to fire, given the combustible nature of timber. Specifically, when unprotected, heat from a fire can conduct through steel beams to the CLT panels, which in turn may experience loss of mechanical properties, and possible charring (and combustion) in the connection zone between the CLT panel and the steel beam. Accordingly, this paper aims to establish thermal profiles in hybrid steel-timber floor cross-sections exposed to fire through experimental and numerical investigations. Results from fire tests and numerical validation studies on hybrid cross-sections exposed to a standard fire are presented; a total of six experiments with unprotected, partially protected, and fully protected steel sections were conducted following an ISO 834-1 standard fire exposure. Furthermore, a two-dimensional numerical heat transfer model was developed using SAFIR software, to predict the evolution of temperatures in the hybrid cross-section. The results confirm that passive fire protection of the steelwork using intumescent coatings plays a key role in determining the extent of charring in the connection region between the CLT panel and the steel section. In addition, temperature predictions from the developed numerical model show reasonable agreement with the experimental measurements.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104593"},"PeriodicalIF":3.3,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579578","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

Numerical simulation of the action of fire-induced wind on wildfire behaviour 火致风对野火影响的数值模拟

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-11 DOI: 10.1016/j.firesaf.2025.104591

Gilbert Accary

The development of fire-induced wind and its action on wildfire behaviour are studied by numerical simulation of fire spread on sloping terrain. The simulations, conducted using a physics-based fire model, are based on a shrubland fire experiment carried out on a 28° sloping terrain under a 1.67 m/s wind-speed, resulting in a high-intensity fire (about 10 MW/m). Three lengths of the ignition line were considered: infinite fire line (simulated using periodic boundary conditions), 30-m-long fire line (as in the experiment), and 90-m-long fire line. Results show that fire-induced wind only occurs in the case of a large fire-front length and that its interaction with the fire front changes fire-spread regime. The highest intensity of fire-induced wind was obtained for an infinite fire front leading to a wind-driven fire with Byram's number less than 2. Induced wind was practically cancelled for a 30-m-long fire line as the fire draws fresh air into the flaming zone from the lateral sides, yielding a plume-dominated fire with Byram's number greater than 10. For a 90-m-long fire line, the intensity of fire-induced wind increased compared to the 30-m-long fire line case, resulting in a transitional fire-spread regime with Byram's number between 2 and 10.

通过对斜坡地形上火灾蔓延的数值模拟，研究了火风的发展及其对野火行为的影响。模拟使用基于物理的火灾模型，基于在28°斜坡地形上进行的灌木丛火灾实验，风速为1.67 m/s，导致高强度火灾（约10 MW/m）。考虑三种长度的着火线：无限火线（使用周期性边界条件模拟），30米长的火线（与实验一样）和90米长的火线。结果表明，火灾诱导风只在较大的火线长度下发生，其与火线的相互作用改变了火灾的蔓延状态。在无限火锋处，当拜拉姆数小于2时，火致风强度最大。在30米长的火线上，诱导风实际上被取消了，因为火焰从侧面吸引新鲜空气进入燃烧区域，产生了一种以羽状火焰为主的火灾，Byram数大于10。对于90米长的火线，与30米长的火线情况相比，火灾诱发风的强度增加，导致过渡的火灾蔓延状态，Byram数在2到10之间。

{"title":"Numerical simulation of the action of fire-induced wind on wildfire behaviour","authors":"Gilbert Accary","doi":"10.1016/j.firesaf.2025.104591","DOIUrl":"10.1016/j.firesaf.2025.104591","url":null,"abstract":"<div><div>The development of fire-induced wind and its action on wildfire behaviour are studied by numerical simulation of fire spread on sloping terrain. The simulations, conducted using a physics-based fire model, are based on a shrubland fire experiment carried out on a 28° sloping terrain under a 1.67 m/s wind-speed, resulting in a high-intensity fire (about 10 MW/m). Three lengths of the ignition line were considered: infinite fire line (simulated using periodic boundary conditions), 30-m-long fire line (as in the experiment), and 90-m-long fire line. Results show that fire-induced wind only occurs in the case of a large fire-front length and that its interaction with the fire front changes fire-spread regime. The highest intensity of fire-induced wind was obtained for an infinite fire front leading to a wind-driven fire with Byram's number less than 2. Induced wind was practically cancelled for a 30-m-long fire line as the fire draws fresh air into the flaming zone from the lateral sides, yielding a plume-dominated fire with Byram's number greater than 10. For a 90-m-long fire line, the intensity of fire-induced wind increased compared to the 30-m-long fire line case, resulting in a transitional fire-spread regime with Byram's number between 2 and 10.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104591"},"PeriodicalIF":3.3,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529232","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

The effect of the smoke alarm obligation – Experiences from Germany based on the data from 1998–2022 烟雾报警器义务的影响——基于1998-2022年数据的德国经验

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-11 DOI: 10.1016/j.firesaf.2025.104590

Sebastian Festag

Germany has had over 20 years of experience with the mandatory use of smoke alarms in households, apartments and residential areas. Since the first smoke alarm obligation (SAO), all federal states have now gradually stipulated an SAO in their building codes over different points of time and with different details. In addition to the positive experiences in concrete practical cases, in which smoke alarms warned people of fire, the effect of this regulation measure can be demonstrated statistically by analysing the development of fire fatality risks for Germany overall and in the individual federal states based on significance tests (t-tests). The benefit of this measure is occasionally questioned in public discussion, although the existing studies show positive effects. So far, there has not been sufficient experience or samples for all federal states to provide a statistical answer. The study presented here examines the impact of the SAO in Germany over the period from 1998 to 2022. Compared to previous analyses, this is the first time that data for the period from 2017 to 2022 are included in the analysis. This provides, a differentiation between the SAO for new buildings (SAO_NB) and existing buildings (SAO_EB). The result of the study shows a significant effect in Germany and in 12 of 16 federal states. The positive effects have increased in recent years, as can be seen in comparison with the latest analyses.

德国在强制在家庭、公寓和住宅区安装烟雾报警器方面已有20多年的经验。自第一个烟雾报警器义务（SAO）以来，所有联邦州现在都逐步在其建筑规范中规定了不同时间点和不同细节的SAO。除了在烟雾警报器警告人们注意火灾的具体实际案例中取得的积极经验外，还可以根据显著性检验（t检验）对整个德国和各个联邦州的火灾死亡风险发展情况进行统计分析，从而证明这一管制措施的效果。尽管现有的研究显示出积极的效果，但这种措施的好处偶尔会在公众讨论中受到质疑。到目前为止，还没有足够的经验或样本让所有联邦州提供统计答案。本文介绍的研究考察了1998年至2022年期间SAO对德国的影响。与之前的分析相比，这是第一次将2017年至2022年的数据纳入分析。这提供了新建筑（SAONB）和现有建筑（SAOEB）的SAO之间的区别。研究结果显示，在德国和16个联邦州中的12个州，这种做法产生了显著影响。从最近的分析可以看出，近年来积极的影响有所增加。

{"title":"The effect of the smoke alarm obligation – Experiences from Germany based on the data from 1998–2022","authors":"Sebastian Festag","doi":"10.1016/j.firesaf.2025.104590","DOIUrl":"10.1016/j.firesaf.2025.104590","url":null,"abstract":"<div><div>Germany has had over 20 years of experience with the mandatory use of smoke alarms in households, apartments and residential areas. Since the first smoke alarm obligation (SAO), all federal states have now gradually stipulated an SAO in their building codes over different points of time and with different details. In addition to the positive experiences in concrete practical cases, in which smoke alarms warned people of fire, the effect of this regulation measure can be demonstrated statistically by analysing the development of fire fatality risks for Germany overall and in the individual federal states based on significance tests (t-tests). The benefit of this measure is occasionally questioned in public discussion, although the existing studies show positive effects. So far, there has not been sufficient experience or samples for all federal states to provide a statistical answer. The study presented here examines the impact of the SAO in Germany over the period from 1998 to 2022. Compared to previous analyses, this is the first time that data for the period from 2017 to 2022 are included in the analysis. This provides, a differentiation between the SAO for new buildings (SAO<sub>NB</sub>) and existing buildings (SAO<sub>EB</sub>). The result of the study shows a significant effect in Germany and in 12 of 16 federal states. The positive effects have increased in recent years, as can be seen in comparison with the latest analyses.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104590"},"PeriodicalIF":3.3,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579575","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

Buoyancy effects on combustion products from high-pressure hydrogen jet flames 高压氢射流火焰燃烧产物的浮力效应

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-11 DOI: 10.1016/j.firesaf.2025.104587

Thushadh Wijesekere, Marcus Runefors, Konrad Wilkens Flecknoe-Brown

Due to the lower radiative fraction and typically higher storage pressures, gas temperatures can often result in longer safety distances compared to radiative heat transfer for hydrogen jet flames. The high temperatures, however, also lead to a low density causing the flow to rise at a certain distance from the release. Unfortunately, a model to determine this distance, similar to what is available for unignited releases, is currently not available which this paper aim to provide. An experimental study was conducted investigating the buoyancy effect on ignited horizontal hydrogen jet releases with different release diameters. The invisible hydrogen plume was visualized using a Background Oriented Schlieren technique (BOS). The transition of the initial momentum-driven jet into a fully buoyancy-driven jet was estimated by following the gradient of the centerline of the plume. A model based on the Froude number of the release similar to the model for unignited releases was developed and the distance showed a very similar dependence on the Froude number, but giving consistently approximately 39% shorter distances.

由于较低的辐射分数和通常较高的储存压力，与氢喷射火焰的辐射传热相比，气体温度通常会导致更长的安全距离。然而，高温也会导致低密度，使流量在距离释放点一定距离处上升。不幸的是，一个模型来确定这个距离，类似于可用的未点燃的释放，目前是不可用的，这篇论文的目的是提供。通过实验研究了不同释放直径的点燃氢射流水平释放的浮力效应。使用背景定向纹影技术（BOS）对不可见的氢羽进行了可视化。根据羽流中心线的梯度，估计了初始动量驱动射流向完全浮力驱动射流的转变。建立了一个基于弗劳德数的模型，该模型与未点燃释放的模型相似，距离对弗劳德数的依赖非常相似，但始终给出约39%的短距离。

{"title":"Buoyancy effects on combustion products from high-pressure hydrogen jet flames","authors":"Thushadh Wijesekere, Marcus Runefors, Konrad Wilkens Flecknoe-Brown","doi":"10.1016/j.firesaf.2025.104587","DOIUrl":"10.1016/j.firesaf.2025.104587","url":null,"abstract":"<div><div>Due to the lower radiative fraction and typically higher storage pressures, gas temperatures can often result in longer safety distances compared to radiative heat transfer for hydrogen jet flames. The high temperatures, however, also lead to a low density causing the flow to rise at a certain distance from the release. Unfortunately, a model to determine this distance, similar to what is available for unignited releases, is currently not available which this paper aim to provide. An experimental study was conducted investigating the buoyancy effect on ignited horizontal hydrogen jet releases with different release diameters. The invisible hydrogen plume was visualized using a Background Oriented Schlieren technique (BOS). The transition of the initial momentum-driven jet into a fully buoyancy-driven jet was estimated by following the gradient of the centerline of the plume. A model based on the Froude number of the release similar to the model for unignited releases was developed and the distance showed a very similar dependence on the Froude number, but giving consistently approximately 39% shorter distances.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104587"},"PeriodicalIF":3.3,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529235","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

Characteristic Compartment Fire Behaviour — A theoretical study encompassing a broader range of regimes 特征隔间火灾行为-一个理论研究，包括更广泛的制度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104589

A.H. Majdalani , I. Calderón , W. Jahn , J.L. Torero

Scaling analysis is used to characterise a series of ten different possible compartment fire scenarios as a function of compartment geometry and ventilation. In addition to the classic scenarios corresponding to Regime I and Regime II fires, eight additional cases were analysed showing that the flow characteristics are generally a function only of the Froude and Euler non-dimensional parameters. All ten scenarios can be described or bounded by the two classic and limiting regimes of behaviour, nevertheless five intermediate scenarios require spatial resolution to achieve a precise characterisation. Therefore, simple scaling analysis appears sufficient to deliver an adequate assessment of all parameters needed to define the heat transfer from the fire to the compartment until burnout of the available combustible compartment contents. The present analysis highlights the specific areas where spatial resolution is required and the potential limitations associated to the use of more detailed tools, such as CFD, for quantification in these specific areas.

尺度分析用于描述一系列十种不同的可能的隔间火灾场景，作为隔间几何形状和通风的函数。除了对应于状态I和状态II火灾的经典场景外，还分析了另外8个案例，表明流动特性通常仅是Froude和Euler无量纲参数的函数。所有十种情景都可以用两种经典和限制的行为模式来描述或限定，然而，五种中间情景需要空间分辨率来实现精确的特征描述。因此，简单的尺度分析似乎足以提供所需的所有参数的充分评估，以确定从火到隔间的热量传递，直到可用的可燃隔间内容物燃尽。目前的分析强调了需要空间分辨率的特定领域，以及在这些特定领域使用更详细的工具（如CFD）进行量化的潜在限制。

{"title":"Characteristic Compartment Fire Behaviour — A theoretical study encompassing a broader range of regimes","authors":"A.H. Majdalani , I. Calderón , W. Jahn , J.L. Torero","doi":"10.1016/j.firesaf.2025.104589","DOIUrl":"10.1016/j.firesaf.2025.104589","url":null,"abstract":"<div><div>Scaling analysis is used to characterise a series of ten different possible compartment fire scenarios as a function of compartment geometry and ventilation. In addition to the classic scenarios corresponding to <em>Regime I</em> and <em>Regime II</em> fires, eight additional cases were analysed showing that the flow characteristics are generally a function only of the Froude and Euler non-dimensional parameters. All ten scenarios can be described or bounded by the two classic and limiting <em>regimes of behaviour</em>, nevertheless five intermediate scenarios require spatial resolution to achieve a precise characterisation. Therefore, simple scaling analysis appears sufficient to deliver an adequate assessment of all parameters needed to define the heat transfer from the fire to the compartment until burnout of the available combustible compartment contents. The present analysis highlights the specific areas where spatial resolution is required and the potential limitations associated to the use of more detailed tools, such as CFD, for quantification in these specific areas.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104589"},"PeriodicalIF":3.3,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529230","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

Ignition time and heat release rate in upward flame spread: From bench to intermediate scale 向上火焰蔓延时的点火时间和放热率：从工作台到中间尺度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104566

Waseem Hittini , David Lange , Juan P. Hidalgo , Felix Wiesner

This research assesses the effect of two common assumptions in simplified flame spread models: (i) that the pyrolysis front propagates in one dimension and (ii) that ignition time (

t_{ign}

) and heat release rate per unit area (HRRPUA) values measured at bench scale can be utilised in simplified flame spread models. To that aim, the study introduces a methodology to measure time to ignition, time-dependent burning area, heat release rate per unit area, and ignition temperature for concurrent upward flame spread at intermediate-scale, while examining the feasibility of using these metrics to predict flame spread scenarios. The methodology employs a narrow-spectrum illumination source and thermocouple arrays to precisely track the pyrolysis front progression during flame spread experiment. Measurements were obtained for Poly(methyl methacrylate), and they can serve as reference points for researchers aiming to develop or refine testing protocols or perform sensitivity analyses for assumptions relevant to time to ignition and heat release rate models. Measurements were compared with cone calorimeter data from standard and modified testing protocols in the literature. Post-ignition removal of external heating reduced HRRPUA values, aligning them more closely with intermediate-scale experiments, while spatial heat flux distribution changed the time to ignition towards the values that were measured in intermediate-scale. The impact of the solid ignition parameters on the flame spread rate was evaluated individually using a simplified flame spread model. The proposed methodology provides a means to refine extrapolation methods for solid ignition parameters.

本研究评估了简化火焰传播模型中两个常见假设的影响：(i)热解锋面在一维上传播；（ii）在台架尺度上测量的点火时间（tin）和单位面积放热率（HRRPUA）值可用于简化火焰传播模型。为此，该研究引入了一种方法来测量点火时间、随时间变化的燃烧面积、单位面积的放热率以及在中等规模下同步向上火焰蔓延的点火温度，同时检查使用这些指标预测火焰蔓延情景的可行性。该方法采用窄谱照明光源和热电偶阵列来精确跟踪火焰蔓延实验过程中的热解前沿进程。获得了聚（甲基丙烯酸甲酯）的测量值，它们可以作为研究人员的参考点，旨在开发或完善测试方案，或对点火时间和热释放率模型相关的假设进行敏感性分析。测量结果与文献中来自标准和修改的测试方案的锥量热计数据进行比较。点火后去除外部加热降低了HRRPUA值，使其与中尺度实验更接近，而空间热通量分布使点火时间向中尺度实验值靠拢。采用简化的火焰传播模型，分别评价了固体点火参数对火焰传播速率的影响。提出的方法为固体点火参数的外推方法提供了一种改进方法。

{"title":"Ignition time and heat release rate in upward flame spread: From bench to intermediate scale","authors":"Waseem Hittini , David Lange , Juan P. Hidalgo , Felix Wiesner","doi":"10.1016/j.firesaf.2025.104566","DOIUrl":"10.1016/j.firesaf.2025.104566","url":null,"abstract":"<div><div>This research assesses the effect of two common assumptions in simplified flame spread models: (i) that the pyrolysis front propagates in one dimension and (ii) that ignition time (<span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>ign</mi></mrow></msub></math></span>) and heat release rate per unit area (HRRPUA) values measured at bench scale can be utilised in simplified flame spread models. To that aim, the study introduces a methodology to measure time to ignition, time-dependent burning area, heat release rate per unit area, and ignition temperature for concurrent upward flame spread at intermediate-scale, while examining the feasibility of using these metrics to predict flame spread scenarios. The methodology employs a narrow-spectrum illumination source and thermocouple arrays to precisely track the pyrolysis front progression during flame spread experiment. Measurements were obtained for Poly(methyl methacrylate), and they can serve as reference points for researchers aiming to develop or refine testing protocols or perform sensitivity analyses for assumptions relevant to time to ignition and heat release rate models. Measurements were compared with cone calorimeter data from standard and modified testing protocols in the literature. Post-ignition removal of external heating reduced HRRPUA values, aligning them more closely with intermediate-scale experiments, while spatial heat flux distribution changed the time to ignition towards the values that were measured in intermediate-scale. The impact of the solid ignition parameters on the flame spread rate was evaluated individually using a simplified flame spread model. The proposed methodology provides a means to refine extrapolation methods for solid ignition parameters.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104566"},"PeriodicalIF":3.3,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579576","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

Understanding the role of buoyancy and inertia in wind-aided vegetative fires 了解浮力和惯性在风助植物火灾中的作用

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-08 DOI: 10.1016/j.firesaf.2025.104588

Abhinandan Singh , Juan Cuevas , Reza Ziazi , Pedro Reszka , Albert Simeoni

The combined effects of buoyancy and inertia forces are studied for wind-aided vegetative fires. Two fuels - Pinus palustris (PP) and Pinus rigida (PR) are tested at five different wind conditions. The flame geometrical parameters are normalized using the flame height and scaled against the inverse of the Froude number (

Fr

). A power-law relationship is observed between all the flame geometrical parameters and

1 / Fr

. The instantaneous rate of spread is calculated using an image analysis algorithm by separating flame impingement and flame spread. The behavior of the average rate of spread is explored by evaluating radiative heat flux in the preheating region. The fluctuating rate of spread (

R^{'}

) is calculated from the instantaneous and average rate of spread values. The spectral analysis of

R^{'}

shows a range of frequencies that are an integer multiple (or harmonics) of the characteristic frequency for a given experiment. Strouhal number (St) evaluated using the characteristic frequency multiplied by the leaf area index of the pine needle bed shows a linear behavior against

1 / Fr

.

研究了风助植物火灾中浮力和惯性力的联合作用。两种燃料——palustris Pinus （PP）和Pinus rigida （PR）在五种不同的风力条件下进行了测试。火焰几何参数使用火焰高度归一化，并根据弗劳德数（Fr）的倒数进行缩放。火焰几何参数与1/Fr呈幂律关系。通过分离火焰撞击和火焰蔓延，采用图像分析算法计算瞬时传播速率。通过估算预热区的辐射热流密度，探讨了平均扩散率的变化规律。从差值的瞬时速率和平均速率计算差值的波动速率（R '）。R '的频谱分析显示了一个频率范围，它是给定实验的特征频率的整数倍（或谐波）。用特征频率乘以松针床叶面积指数计算的斯特劳哈尔数（St）与1/Fr呈线性关系。

{"title":"Understanding the role of buoyancy and inertia in wind-aided vegetative fires","authors":"Abhinandan Singh , Juan Cuevas , Reza Ziazi , Pedro Reszka , Albert Simeoni","doi":"10.1016/j.firesaf.2025.104588","DOIUrl":"10.1016/j.firesaf.2025.104588","url":null,"abstract":"<div><div>The combined effects of buoyancy and inertia forces are studied for wind-aided vegetative fires. Two fuels - <em>Pinus palustris</em> (<em>PP</em>) and <em>Pinus rigida</em> (<em>PR</em>) are tested at five different wind conditions. The flame geometrical parameters are normalized using the flame height and scaled against the inverse of the Froude number (<span><math><mi>Fr</mi></math></span>). A power-law relationship is observed between all the flame geometrical parameters and <span><math><mrow><mn>1</mn><mo>/</mo><mi>Fr</mi></mrow></math></span>. The instantaneous rate of spread is calculated using an image analysis algorithm by separating flame impingement and flame spread. The behavior of the average rate of spread is explored by evaluating radiative heat flux in the preheating region. The fluctuating rate of spread (<span><math><msup><mrow><mi>R</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span>) is calculated from the instantaneous and average rate of spread values. The spectral analysis of <span><math><msup><mrow><mi>R</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> shows a range of frequencies that are an integer multiple (or harmonics) of the characteristic frequency for a given experiment. Strouhal number (St) evaluated using the characteristic frequency multiplied by the leaf area index of the pine needle bed shows a linear behavior against <span><math><mrow><mn>1</mn><mo>/</mo><mi>Fr</mi></mrow></math></span>.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104588"},"PeriodicalIF":3.3,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579577","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

Preventing fire-induced brittle collapse of steel tubular space trusses for reliable early warning: From mechanisms to design strategy 防止钢管空间桁架火灾脆性倒塌的可靠预警：从机理到设计策略

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104586

Jinyu Li , Shaojun Zhu , Guo-Qiang Li , Yongchang Wang

Steel tubular space truss structures are widely utilized in large-space buildings but are highly susceptible to collapse under fire conditions, posing a threat to firefighters. This study conducts extensive parametric analyses to understand all fire-induced collapse modes and mechanisms of steel tubular space trusses. There are four collapse modes, of which three are categorized as ductile and one is classified as brittle due to buckling of the web members in compression. Under the brittle collapse mode, it is difficult to reliably predict the collapse of the structure for real-time early warning. This paper recommends the elimination of this failure mode in all likely fire scenarios. A design strategy is proposed to ensure that the brittle buckling failure mode of web members does not happen before that of the adjacent members in tension, whose failure is ductile. Besides, the available escape time after the early warning level is issued can be changed by adjusting the critical temperatures of the compression web members. Numerical examples demonstrate that the available escape time can increase from 0 s to over 2 min, which increases the escape time for firefighters in large-span steel structures.

钢管空间桁架结构广泛应用于大空间建筑，但在火灾条件下极易倒塌，对消防人员构成威胁。本研究进行了广泛的参数分析，以了解钢管空间桁架的所有火灾倒塌模式和机制。有四种破坏模式，其中三种为延性破坏模式，一种为脆性破坏模式，这是由于腹板在压缩下的屈曲造成的。在脆性破坏模式下，很难对结构的破坏进行可靠的预测和实时预警。本文建议在所有可能的火灾场景中消除这种故障模式。提出了一种保证腹板构件脆性屈曲破坏模式不先于相邻构件脆性屈曲破坏模式发生的设计策略。通过调整压缩腹板构件的临界温度，可以改变预警级别发布后的有效逃生时间。数值算例表明，在大跨度钢结构中，有效逃生时间由0 s增加到2 min以上，增加了消防员的逃生时间。

{"title":"Preventing fire-induced brittle collapse of steel tubular space trusses for reliable early warning: From mechanisms to design strategy","authors":"Jinyu Li , Shaojun Zhu , Guo-Qiang Li , Yongchang Wang","doi":"10.1016/j.firesaf.2025.104586","DOIUrl":"10.1016/j.firesaf.2025.104586","url":null,"abstract":"<div><div>Steel tubular space truss structures are widely utilized in large-space buildings but are highly susceptible to collapse under fire conditions, posing a threat to firefighters. This study conducts extensive parametric analyses to understand all fire-induced collapse modes and mechanisms of steel tubular space trusses. There are four collapse modes, of which three are categorized as ductile and one is classified as brittle due to buckling of the web members in compression. Under the brittle collapse mode, it is difficult to reliably predict the collapse of the structure for real-time early warning. This paper recommends the elimination of this failure mode in all likely fire scenarios. A design strategy is proposed to ensure that the brittle buckling failure mode of web members does not happen before that of the adjacent members in tension, whose failure is ductile. Besides, the available escape time after the early warning level is issued can be changed by adjusting the critical temperatures of the compression web members. Numerical examples demonstrate that the available escape time can increase from 0 s to over 2 min, which increases the escape time for firefighters in large-span steel structures.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104586"},"PeriodicalIF":3.3,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529233","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

Towards modeling tree-to-tree fire spread in wildland urban-interface (WUI) fires 林地城市界面（WUI）火灾中树对树的火灾传播模型研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104550

Jorge Valdivia, Xiuqi Xi, Albert Simeoni, James L. Urban

Wildfires in the Wildland-Urban Interface (WUI) have intensified in recent years due to climate change and continued development of communities at the WUI. Defensible space–reducing vegetation near structures–is a mitigation strategy, but its performance under wind-driven fire conditions remains unclear. This study integrates controlled experiments with Fire Dynamics Simulator (FDS) modeling to investigate ignition between trees subjected to wind-aided flame spread. A custom-designed propane burner, representing fire exposure similar to a 2 MW tree fire, exposed downwind Douglas-fir trees under flow velocities of 1.0 and 2.0 m s⁻¹, across varying separation distances. Total and radiative heat fluxes were measured using water-cooled gauges, and ignition behavior was evaluated through logistic regression. Flame impingement emerged as the dominant ignition mechanism, with convection significantly increasing heat transfer to downwind trees at short separation distances. Simulations reproduced key trends in heat flux and flame geometry but over-predicted radiation and under-predicted convection, especially at short separations. Critical ignition distances increased with wind speed, highlighting the role of wind-driven flame elongation and the need for flow-aware defensible space recommendations. The experiments provide insight into the use of computational fire modeling to inform defensible space guidelines tailored to specific environmental and fire conditions.

近年来，由于气候变化和城市交界面社区的持续发展，城市交界面地区的野火愈演愈烈。可防御的空间——减少建筑物附近的植被——是一种缓解策略，但它在风力驱动的火灾条件下的表现仍不清楚。本研究将对照实验与火焰动力学模拟器（FDS）模型相结合，研究了风助火焰传播下树木之间的点火情况。一个定制设计的丙烷燃烧器，代表了类似于2兆瓦树木火灾的火灾暴露，在1.0和2.0 m s- 1的流速下，在不同的分离距离上暴露下风道格拉斯冷杉树。用水冷计测量总热流和辐射热通量，并通过逻辑回归评估点火行为。火焰碰撞是主要的点火机制，对流显著增加了短间隔距离下风向树木的传热。模拟再现了热通量和火焰几何形状的关键趋势，但高估了辐射，而低估了对流，特别是在短间隔时。临界点火距离随着风速的增加而增加，这突出了风驱动火焰延伸的作用，以及对流动感知防御空间建议的需求。这些实验提供了对使用计算火灾模型的洞察力，以告知针对特定环境和火灾条件量身定制的防御空间指南。

{"title":"Towards modeling tree-to-tree fire spread in wildland urban-interface (WUI) fires","authors":"Jorge Valdivia, Xiuqi Xi, Albert Simeoni, James L. Urban","doi":"10.1016/j.firesaf.2025.104550","DOIUrl":"10.1016/j.firesaf.2025.104550","url":null,"abstract":"<div><div>Wildfires in the Wildland-Urban Interface (WUI) have intensified in recent years due to climate change and continued development of communities at the WUI. Defensible space–reducing vegetation near structures–is a mitigation strategy, but its performance under wind-driven fire conditions remains unclear. This study integrates controlled experiments with Fire Dynamics Simulator (FDS) modeling to investigate ignition between trees subjected to wind-aided flame spread. A custom-designed propane burner, representing fire exposure similar to a 2 MW tree fire, exposed downwind Douglas-fir trees under flow velocities of 1.0 and 2.0 ms<sup>−1</sup>, across varying separation distances. Total and radiative heat fluxes were measured using water-cooled gauges, and ignition behavior was evaluated through logistic regression. Flame impingement emerged as the dominant ignition mechanism, with convection significantly increasing heat transfer to downwind trees at short separation distances. Simulations reproduced key trends in heat flux and flame geometry but over-predicted radiation and under-predicted convection, especially at short separations. Critical ignition distances increased with wind speed, highlighting the role of wind-driven flame elongation and the need for flow-aware defensible space recommendations. The experiments provide insight into the use of computational fire modeling to inform defensible space guidelines tailored to specific environmental and fire conditions.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"159 ","pages":"Article 104550"},"PeriodicalIF":3.3,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529237","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