Fire Safety Journal最新文献

{"title":"Thermal runaway discrete propagation mechanisms and fire characteristics of lithium-ion battery modules with typical electrical structures","authors":"Yan Cui ,&nbsp;Jianghong Liu ,&nbsp;Beihua Cong ,&nbsp;Weiguo Song ,&nbsp;Mingming Qiu ,&nbsp;Sumiao Yin","doi":"10.1016/j.firesaf.2025.104542","DOIUrl":"10.1016/j.firesaf.2025.104542","url":null,"abstract":"<div><div>Conflagrations originating from the thermal instability of lithium-ion batteries (LIBs) have posed a serious hazard to public safety. The fire dynamics of the system-level LIB pack with complex electrical topologies is still unclear. This paper focused on the phenomenon of thermal runaway (TR) discrete propagation, which spreads TR among the LIB pack leapingly, and conducted thermophysical experiments. Laboratory-scale LIB modules with typical electric structures were constructed to reveal the mechanisms and patterns of the phenomenon from the cell component level, as well as the fire behaviors and characteristics. The horizontally insulated calorimetric wind tunnel provided the LIB modules with forced air cooling. Results showed that smooth occurrence of TR discrete propagation required the overcharge current that facilitated the steady and concentrated growth of lithium dendrites and the overcharged battery interior that maintained the low temperature and gas pressure before the lithium dendrites pierced the separator. Under these experimental conditions, it occurred when the charge state of the battery remote from the heat source exceeded 135.56 %, with a minimum onset temperature of 64.6 °C. Its concomitant electricity transmission from external short circuits lowered the TR onset temperature of the LIB submodule and hastened the spread rate of TR. The heat release rate of the burning LIB module peaked at 35.612 kW, while each cell reached a total heat release of 107.468 kJ, and the duration of each flaming was not affected by TR discrete propagation. The results provide insight into the fire mechanisms and characteristics of the high LIB concentration scenario.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104542"},"PeriodicalIF":3.3,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159745","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}

{"title":"Heat exposure from electric vehicle fires: Experimental results and analysis","authors":"Parham Dehghani,&nbsp;Matthew DiDomizio,&nbsp;Nathaniel Sauer,&nbsp;Adam Barowy","doi":"10.1016/j.firesaf.2025.104535","DOIUrl":"10.1016/j.firesaf.2025.104535","url":null,"abstract":"<div><div>Free-burning of a Tesla Model 3 and a Chevrolet Bolt was studied under controlled conditions. Heat release rates were estimated from mass loss measurements. Fire-induced heat flux distribution was captured using infrared thermography of high-emissivity plate sensors placed on each vehicle side, supplemented by eight Schmidt-Boelter radiometers. A point-source model (PSM) was used to estimate heat flux over the plate area, allowing comparison with the measured data using an approach that fire safety engineers readily employ.</div><div>Plate sensors revealed local peaks in heat flux that were not resolved by the radiometers due to their limited spatial coverage. When measured flame heights were used in the PSM, peak exposures were underpredicted by 1.4% (Bolt) and 18.3% (Tesla). However, when flame heights were estimated from heat release rates, a common assumption in engineering analyses, underpredictions increased to 64.5% (Bolt) and 53.1% (Tesla). Additionally, both plate and radiometer data were used to assess three battery jetting events that occurred before cabin involvement. Jetting-related heat flux peaks ranged from 7.9% to 100% of the global maximum measured during the free-burn, indicating their potentially significant contribution to heat exposure prior to full vehicle involvement.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104535"},"PeriodicalIF":3.3,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159743","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}

{"title":"Development of ghosting flames in an under-ventilated compartment","authors":"Ryan Falkenstein-Smith ,&nbsp;Katherine Hinnant ,&nbsp;Aika Davis ,&nbsp;Thomas Cleary","doi":"10.1016/j.firesaf.2025.104533","DOIUrl":"10.1016/j.firesaf.2025.104533","url":null,"abstract":"<div><div>This work examines the transition of an enclosure fire to an under-ventilated scenario such that conditions are conducive to a ghosting flame within the enclosure. Ghosting flames were observed when flames generated from a burner using propane were lifted off the burner and sporadically occupied other regions of the compartment. All experiments were conducted within a reduced-scale enclosure with a varying width of either 2.0 cm, 4.0 cm, or 10.0 cm. Each opening configuration was subjected to a range of fire sizes within the enclosure to determine the conditions conducive to ghosting flame. The compartment was observed to transition to under-ventilated conditions, such that significant concentrations of hydrocarbons were generated within the enclosure when the global equivalence ratio in the upper region was equal to 1. Ghosting flames were observed when the measured global equivalence ratio in the upper compartment region reached 2.3 <span><math><mo>±</mo></math></span> 0.2 and were found to continuously occur as the ratio continued to exceed that value steadily. This suggests that a ghosting flame phenomenon occurs when the rate at which fuel is introduced is more than a factor of ten relative to the airflow into the compartment.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104533"},"PeriodicalIF":3.3,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119920","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}

{"title":"Conditions for onset and sustained char oxidation","authors":"Laura Schmidt,&nbsp;Rory M. Hadden","doi":"10.1016/j.firesaf.2025.104539","DOIUrl":"10.1016/j.firesaf.2025.104539","url":null,"abstract":"<div><div>Smouldering combustion of timber presents a significant fire safety concern, particularly in scenarios where heat retention enables sustained char oxidation. This study isolates char oxidation from other smouldering processes to investigate its onset and sustained reaction under close-to-critical incident heat fluxes. Experiments using pre-pyrolysed char samples provided direct measurements of CO and CO₂ generation, mass loss, and temperature evolution during char oxidation. The onset of char oxidation was characterised by a rapid increase in CO generation rate, occurring consistently at an external heat flux of 10 kW/m². Among the methods tested, CO mass flow rates proved to be the most reliable indicator of char oxidation onset, offering greater precision than traditional mass loss measurements or temperature data in determining the char oxidation onset time. Once initiated, oxidation led to sustained heat release, with in-depth temperatures exceeding 400 °C, peak heat release rates of ∼29 kW/m² and a mean effective heat of combustion of ∼30.3 kJ/g, close to the char's gross heat of combustion, at 10 kW/m². These findings improve the understanding of char oxidation kinetics and support the development of predictive models for smouldering in engineered timber, informing fire hazard assessment and mitigation strategies.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104539"},"PeriodicalIF":3.3,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227619","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}

{"title":"Numerical and experimental investigation of shaft-like compartment fires","authors":"Rabah Mehaddi ,&nbsp;Bouaza Lafdal ,&nbsp;Pascal Boulet","doi":"10.1016/j.firesaf.2025.104521","DOIUrl":"10.1016/j.firesaf.2025.104521","url":null,"abstract":"<div><div>The present study focuses on under-ventilated compartment fires, by analysing the results of an experimental and numerical study about fires issuing from heptane pools in a compartment with an open door. This compartment has an aspect ratio (height/width) of the order of 1.8 and a doorway with an aspect ratio up to 4, which is very different from conventional compartments. This type of geometry is therefore expected to yield new results. The key parameters in this case are the ventilation factor (based on the door height and its area) and the pool fire diameter. To analyse the combustion regimes, the fire Heat Release Rate (HRR) is split into two parts, namely, the HRR released inside and outside the compartment. To quantify these quantities, two experimental methods have been combined. The first one is based on temperature measurements inside the compartment. The second one combines measurements from radiative heat fluxes outside the compartment and images taken with visible cameras that provide the flame shape in order to evaluate the corresponding heat released rate. The experimental data have been compared to dedicated numerical simulations carried out with the CFD code Fire Dynamics Simulator. These comparisons have revealed that in a well-ventilated or moderately under-ventilated regime, integral quantities such as mean temperature, fire heat release rate inside and outside the room appear to be well predicted by the simulations. However, under the same conditions, the temperature profiles show differences that can be locally significant. This observation might be explained by a difficulty in correctly reproducing the flame dynamics and the air flow entering through the door. Furthermore, in the severely under-ventilated case, the temporal evolution of the average quantities (HRR and mean temperatures) are very poorly estimated by the simulations, as well as the local distributions. In this case the simulations predict that the combustion of all the combustible vapours occurs outside the door, which does not correspond to the physical observations. This phenomenon have been observed at <span><math><mrow><msup><mrow><mover><mrow><mi>Q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mo>∗</mo></mrow></msup><mo>≈</mo><mn>1</mn><mo>.</mo><mn>6</mn></mrow></math></span>, where <span><math><msup><mrow><mover><mrow><mi>Q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mo>∗</mo></mrow></msup></math></span> is the dimensionless heat released rate. Therefore, improvements of the CFD code are required to improve the simulations, probably also involving dedicated efforts on the ignition and extinction sub-models.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104521"},"PeriodicalIF":3.3,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061294","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}

{"title":"Developing an indicator system for urban fire risk assessment","authors":"Shuai Zhang,&nbsp;Ye Song,&nbsp;Qichang Dong,&nbsp;Hui Yang,&nbsp;Long Shi","doi":"10.1016/j.firesaf.2025.104536","DOIUrl":"10.1016/j.firesaf.2025.104536","url":null,"abstract":"<div><div>With the acceleration of urbanization, the occurrence mechanism of urban fires has become increasingly complex, with various factors intertwined, significantly increasing the difficulty of fire risk assessment and prevention. Therefore, this review focuses on the typical influencing factors of industrial fires, residential fires, and urban wildfires, and classifies them into three types: human, social, and environmental factors. Regarding human factors, insufficient educational level and safety culture are the core causes of human factors in fires, which can lead to unsafe behaviors and increase the fire incidence. In terms of social factors, the level of economic development restricts the overall capacity for fire risk prevention and control by influencing infrastructure investment. Regarding environmental factors, high temperatures and low humidity can increase the flammability of combustibles, while strong winds can accelerate the spread of fire and expand the scale of disaster losses. In addition to meteorological factors, wildfires are also influenced by topographic features. The functional differences in different regions lead to obvious spatial disparities. Human factors mainly dominate the fire risks in industrial zones. For residential areas, human and social factors are the main reasons; in urban green spaces, environmental influences cannot be overlooked. The study shows that urban fire risk is the product of the interaction between human behavior, social systems, and environmental conditions in specific functional scenarios, and functional differentiation exacerbates the spatial heterogeneity of risks.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104536"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050665","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}

{"title":"Stochastic modeling of the flight of embers ejected from an ember dragon","authors":"Nigel B. Kaye ,&nbsp;Khalid Moinuddin ,&nbsp;Rahul Wadhwani","doi":"10.1016/j.firesaf.2025.104523","DOIUrl":"10.1016/j.firesaf.2025.104523","url":null,"abstract":"<div><div>Spot-fire generation from embers blown ahead of a wildfire front is one of the leading causes of home destruction in wildland-urban interface (WUI) fires. It is, therefore, important to be able to model wind-driven ember flight accurately. This study presents the application of a stochastic debris flight model to this problem. The model embeds the uncertainty in flight conditions into the model by randomly perturbing the flight parameters (drag and lift forces) at each numerical integration time step. The stochastic flight model replicates the results of a series of ember flight tests run using the Victoria University ember dragon for both cubic and cylindrical model embers. Results show that the stochastic model produces very good predictions of the mean landing location of the embers tested. The model also provides reasonable estimates of the standard deviation and skewness of the landing location distribution in the direction of the initial launch for the cubic embers. The agreement with higher moment statistics is poorer for the cylindrical embers, though there is qualitative consistency between the experimental and model spatial distributions.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104523"},"PeriodicalIF":3.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050693","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}

{"title":"Characterization of flammability and species yields for PMMA burning at constant equivalence ratios in a fire propagation apparatus","authors":"Farnaz Beygi Khosroshahi,&nbsp;Fernando Raffan-Montoya,&nbsp;Stanislav I. Stoliarov","doi":"10.1016/j.firesaf.2025.104532","DOIUrl":"10.1016/j.firesaf.2025.104532","url":null,"abstract":"<div><div>A new method for the measurement of the heat release rate and products of combustion at constant global equivalence ratios (<em>GER</em>s) was developed. This method was based on a modified Fire Propagation Apparatus (FPA) equipped with O₂, CO₂, CO, total hydrocarbons (THC), particulate matter (PM), NO, and HCN sensors. The control of <em>GER</em> was achieved by administering precisely calibrated, time-varying air flow to the combustion zone. To demonstrate this method's capabilities, the combustion of poly(methyl methacrylate) (PMMA) was investigated at <em>GER</em> ranging from 0.63 to 1.96. The CO₂ yield, expressed as mass of species per mass of pyrolyzate, and heat of combustion were found to monotonically decrease from 2.04 to 1.05 and from 23.6 kJ g⁻¹ to 15.1 kJ g⁻¹, respectively, with increasing <em>GER</em>. Conversely, CO, PM, and THC yields increased from 0.019 to 0.263, from 0.015 to 0.051, and from 0.006 to 0.301, respectively, with increasing <em>GER</em>. Good carbon balance, within ±5 %, was achieved across the entire <em>GER</em> range. The characteristic time the combusting mixture spends in the FPA's test section was identified as another key parameter, alongside <em>GER</em>, that affected both species production and heat release. An empirical model was developed and validated to fully capture these dependencies.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104532"},"PeriodicalIF":3.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050687","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}

{"title":"Revisiting the BS 8414 timber crib: An experimental investigation for enhancing facade fire safety","authors":"Konstantinos Chotzoglou ,&nbsp;Talal Fateh","doi":"10.1016/j.firesaf.2025.104522","DOIUrl":"10.1016/j.firesaf.2025.104522","url":null,"abstract":"<div><div>In the aftermath of the Grenfell Tower tragedy, the fire performance of external wall systems (EWS) and the timber crib fire source specified in BS 8414 have come under increasing scrutiny. This study presents a comprehensive experimental investigation into the burning characteristics and heat exposure effects of the BS 8414 timber crib. A two-scale approach was employed, combining bench-scale calorimetry (ISO 1716) and large-scale testing in both free-burn and chamber configurations, to evaluate the consistency, intensity, and thermal output of the fire source. Key parameters such as heat release rate (HRR), mass loss rate (MLR), temperature evolution, and incident heat flux on an inert façade were measured. The results demonstrate good repeatability and reveal that the actual heat output often exceeds the standard's prescribed values, exposing the façade to high-intensity thermal loads sufficient to ignite many cladding materials. The findings also indicate that the BS 8414 setup more closely resembles an external fire scenario rather than a post-flashover room fire, due to the chamber's geometry and fuel placement. This research provides valuable benchmark data that may inform regulatory bodies, standardization committees, and engineers, contributing to improved testing methodologies and the development of safer façade fire standards for high-rise buildings.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104522"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996692","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}

{"title":"Simple prediction equation for ceiling jet flow arrival time in space without vertical wall soffit","authors":"Hyewon Kim ,&nbsp;Jun-ichi Yamaguchi ,&nbsp;Hyun-woo Park ,&nbsp;Yoshifumi Ohmiya","doi":"10.1016/j.firesaf.2025.104520","DOIUrl":"10.1016/j.firesaf.2025.104520","url":null,"abstract":"<div><div>Currently, in two-zone models, smoke flow is calculated based on the assumption that the fire plume, which develops directly above the fire source, depends solely on the amount of entrained surrounding air. However, in large flat spaces, which have been growing larger in recent years, the horizontal travel distance of ceiling jet flow is long, and it is possible that the amount of smoke due to entrainment of air during the horizontal spread process is underestimated. In this study, we performed experiments that reproduced an unconfined ceiling without a vertical wall soffit and determined the amount of entrainment in the ceiling jet flow by analyzing the gas concentration of ceiling jet flow at various flow distances. Next, we formulated the ceiling jet flow rate by expressing this in terms of dimensionless flow rate and dimensionless flow distance. Furthermore, we derived a simple prediction equation for ceiling jet flow arrival time based on the model equation. Finally, we validated the proposed equation and range of applicability through comparison with the results of several experiments.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104520"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050695","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}