Mingzhao Wang , Xiaoping Wen , Zhihan Yuan , Haoxin Deng , Jun Song , Guoyan Chen , Fahui Wang , Rongkun Pan
{"title":"Experimental study of the combined effects of CO2 and obstacles on the explosive behavior of syngas","authors":"Mingzhao Wang , Xiaoping Wen , Zhihan Yuan , Haoxin Deng , Jun Song , Guoyan Chen , Fahui Wang , Rongkun Pan","doi":"10.1016/j.firesaf.2025.104355","DOIUrl":"10.1016/j.firesaf.2025.104355","url":null,"abstract":"<div><div>This article experimentally investigates the explosion behaviors of syngas, focusing on the combined effects of obstacles and CO<sub>2</sub> on flame front evolution, flame front velocity (FFV), overpressure, and maximum overpressure (P<sub>max</sub>). Results demonstrate that CO<sub>2</sub> prolongs the flame propagation time, with increasing concentration delaying the onset time of the tulip flame (t<sub>tulip</sub>). A secondary tulip phenomenon is observed at α(H<sub>2</sub>) = 30 % and α(CO<sub>2</sub>) = 20 %. For pipes with obstacles, increasing CO<sub>2</sub> concentration reduces the impact of the obstacles on flame propagation, slows the flame front velocity, and causes the flame front to exhibit different shapes after passing through the obstacle. As α(H<sub>2</sub>) increases, the overpressure also rises substantially, with P<sub>max</sub> increasing up to 3.74 times compared to the scenario without obstacles. When α(CO<sub>2</sub>) reaches 15 %–20 %, the P<sub>max</sub> without obstacles surpasses that with obstacles, suggesting that at higher α(CO<sub>2</sub>), the obstacles have a minimal impact on the gas explosion, with α(CO<sub>2</sub>) becoming the dominant factor.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"153 ","pages":"Article 104355"},"PeriodicalIF":3.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453308","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}
Robert Kowalski , Michał Głowacki , Julia Wróblewska , Małgorzata Senatorska-Dobrowolska , Piotr Smardz
{"title":"Dangerous damage of RC structural members caused by thermal spalling of concrete during fire in an enclosed car park of residential building","authors":"Robert Kowalski , Michał Głowacki , Julia Wróblewska , Małgorzata Senatorska-Dobrowolska , Piotr Smardz","doi":"10.1016/j.firesaf.2025.104352","DOIUrl":"10.1016/j.firesaf.2025.104352","url":null,"abstract":"<div><div>This paper presents a description of structural damage caused by a fire in an underground car park of a six-storey residential building. It also describes how the damaged members were repaired. It was found that the fire had reached the fully developed stage over a large area of the car park, which resulted in considerable extent of damage: (1) approximately 210 m<sup>2</sup> of the ceiling slab were completely destroyed - it was necessary to demolish the slab and replace it with a new one, (2) one of the walls constituting the main load-bearing structure of the building was in a state very close to actual destruction, (3) several columns required significant strengthening. The main cause of the resulting damage was the unusually intense thermal spalling of the concrete.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104352"},"PeriodicalIF":3.4,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A numerical model for predicting the smoldering behavior of bio-based insulation materials: Model theory and validation","authors":"Patrick Sudhoff , Ulrich Krause","doi":"10.1016/j.firesaf.2025.104351","DOIUrl":"10.1016/j.firesaf.2025.104351","url":null,"abstract":"<div><div>Bio-based insulation materials are prone to self-sustained smoldering after ignition. While empirical studies highlight key factors influencing smoldering initiation and spread, a comprehensive understanding of the mechanisms remains incomplete. This study introduces a smoldering model for bio-based insulation materials, integrating flow, heat, and moisture transfer with a 3-step reaction model.</div><div>Material parameter quantification is demonstrated using wood fiber insulation as a reference, with methodologies applicable to other materials. Experimental setups for fluid mechanical, thermal, and moisture transport properties are described, supplemented by data from literature.</div><div>The modeling framework couples flow, heat, and moisture transport mechanisms with reaction rates dependent on temperature and concentration. A diffusion-limiting approach accounts for particle-surface transport constraints. Implementation is performed using COMSOL Multiphysics ® 6.</div><div>Validation tests in a 1.5 m tube furnace with controlled heating zones and inflow conditions demonstrate the model's ability to accurately predict smoldering velocity. Further optimization is required to improve ignition time predictions. While some inhomogeneity effects are not fully captured, the model provides a solid foundation for further refinement and scaling to component levels.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104351"},"PeriodicalIF":3.4,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tássia L.S. Quaresma , Tristan Hehnen , Lukas Arnold
{"title":"The influence of small mass loss rate peaks on the rate of spread of predictive flame spread simulations: A theoretical study","authors":"Tássia L.S. Quaresma , Tristan Hehnen , Lukas Arnold","doi":"10.1016/j.firesaf.2025.104344","DOIUrl":"10.1016/j.firesaf.2025.104344","url":null,"abstract":"<div><div>Peaks in the mass loss rate (MLR) curve derived from thermogravimetric analysis (TGA) are commonly used to infer the pyrolysis rates of solid fuels. While the main peaks are often modelled, smaller MLR fluctuations are typically neglected, leading to discrepancies between models and experiments. The impact of these small fluctuations on key simulation predictions, however, remains unclear. This study systematically explores a specific scenario in which a small MLR fluctuation significantly affects the predicted rate of spread (ROS) of a simplified flame spread simulation. The MaCFP-recommended pyrolysis model for poly(methyl methacrylate) (PMMA) is adapted to incorporate a small MLR peak accounting for 0.5<!--> <!-->% to 2<!--> <!-->% of the sample’s total mass. Results from sensitivity analyses show that the peak position has the greatest impact on the ROS, followed by the peak mass fraction, while the peak width has negligible effect. Adding a small peak at lower temperatures increased the ROS by up to 6<!--> <!-->% to 13<!--> <!-->%, depending on the peak’s mass fraction, whereas peaks at higher temperatures had little to no effect. These results indicate that fluctuations at lower temperatures, w.r.t. the main peak, could significantly enhance the predicted spread rates and should be considered in flame spread simulations.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104344"},"PeriodicalIF":3.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Systems thinking in road tunnel safety: Feasibility of evacuation shelters for single-tube road tunnels","authors":"Jeroen Wiebes , Henrik Bjelland , Ove Njå","doi":"10.1016/j.firesaf.2025.104350","DOIUrl":"10.1016/j.firesaf.2025.104350","url":null,"abstract":"<div><div>The self-rescue principle is fundamental for ensuring tunnel user safety during fires. Major fires in European road tunnels in the late 1990s and early 2000s highlighted the difficulties of evacuating single-tube tunnels with bi-directional traffic and longitudinal ventilation, resulting in an increased emphasis on facilitating self-rescue in road tunnels.</div><div>This article explores the feasibility of shelters, abbreviated to SWETO, as an element in the evacuation system for existing single-tube road tunnels with bi-directional traffic and longitudinal ventilation. The study is a response to recent years’ increased interest in the concept in Norway. Integrating SWETOs presents both engineering and sociotechnical challenges. Functional requirements and solutions are lacking and need developing. However, it is argued that available knowledge supports the concept. A gradual integration of SWETOs in selected high-risk road tunnels is proposed through pilot projects.</div><div>To increase our understanding of SWETOs effectiveness and limitations, knowledge-generating activities such as pilot projects and targeted research are crucial. These efforts should focus on their design, implementation, operation and maintenance to ensure functionality during emergencies. By addressing these aspects, SWETOs can become a valuable component of tunnel safety systems, enhancing the resilience of road tunnels and protecting tunnel users in critical situations.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104350"},"PeriodicalIF":3.4,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiahao Hu , Zhan Wang , Zhi Tang , Hongzheng Li , Can Wang , Zheng Fang
{"title":"Study on the applicability of scaling laws in tunnel fires under natural ventilation conditions","authors":"Jiahao Hu , Zhan Wang , Zhi Tang , Hongzheng Li , Can Wang , Zheng Fang","doi":"10.1016/j.firesaf.2025.104349","DOIUrl":"10.1016/j.firesaf.2025.104349","url":null,"abstract":"<div><div>This article numerically investigates the impact of tunnel scale ratio and fire Heat Release Rate (HRR) on the scaling results of temperature distribution and smoke field in a tunnel under natural ventilation conditions, by preserving Froude (Fr) scaling. Computational fluid dynamics simulations were performed on a 1:8 scale physical tunnel model [1], showing satisfactory agreement between measured data and predicted results. On this basis, four additional numerical models with scales of 1:1, 1:2, 1:4, and 1:16 were built based on Froude scaling principles, considering the scaling of thermal properties of materials and wall thickness. Four HRRs ranging from 3 MW to 50 MW were adopted. The simulation results provide insights into the temperature and flow fields, revealing the influence of tunnel scale ratio, HRR, and wall scaling method on scaling errors. Significant discrepancies found in the smallest tunnel model with a scale ratio of 1:16 were well explained by transitional or laminar flow due to low Reynolds number (Re), which can primarily cause a significant reduction in ceiling jet temperature as well as an increase in smoke arrival time and smoke thickness. Finally, after analyzing scaling errors for practical tunnel fire design scenarios, recommendations are provided for engineering application of selecting appropriate physical scale models for tunnel fire tests.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104349"},"PeriodicalIF":3.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143294193","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}
Alberto Alonso-Pinar , Jean-Baptiste Filippi , Alexander Filkov
{"title":"Modelling aerodynamics and combustion of firebrands in long-range spotting","authors":"Alberto Alonso-Pinar , Jean-Baptiste Filippi , Alexander Filkov","doi":"10.1016/j.firesaf.2025.104348","DOIUrl":"10.1016/j.firesaf.2025.104348","url":null,"abstract":"<div><div>During a wildfire, parts of the vegetation such as twigs or bark can detach, ignite and become firebrands or embers. When they travel ahead from the main fire front, they can ignite secondary fires in a process known as spotting. We introduce <em>pyBrands</em>, an open-source python tool that uses coupled fire-atmosphere simulations to calculate firebrand trajectories. This module integrates aerodynamic and combustion models for firebrands. This study compares the existing drag and lift models, and combustion models for firebrands by simulating a realistic wildfire plume in a large numerical domain. Firebrands with different properties were injected into the plume and their landing densities were compared. Results indicate that travelled distances strongly depend on the aerodynamic and combustion model. This makes the choice of models difficult and impractical due to the required time step. <em>pyBrands</em> could be used to test and develop new models, improving firebrand behavior prediction in wildfires.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104348"},"PeriodicalIF":3.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felix Wiesner , Hangyu Xu , David Lange , Vinny Gupta , Ian Pope , José L. Torero , Juan P. Hidalgo
{"title":"Large-scale compartment fires to develop a self-extinction design framework for mass timber-Part 2: Results, analysis and design implications","authors":"Felix Wiesner , Hangyu Xu , David Lange , Vinny Gupta , Ian Pope , José L. Torero , Juan P. Hidalgo","doi":"10.1016/j.firesaf.2025.104346","DOIUrl":"10.1016/j.firesaf.2025.104346","url":null,"abstract":"<div><div>This paper seeks to provide key fundamental knowledge underpinning the use of self-extinction principles as part of a design framework for buildings with engineered mass timber structures. The results from six compartment fire experiments in a cross-laminated timber (CLT) enclosure with different ratios of exposed timber are presented and analyzed to establish the effects of timber exposure on the dynamics of a fire and on the potential of the fire to self-extinguish. The results show the relevance of four key parameters that need to be considered concurrently when assessing self-extinction in mass timber compartments: (a) the characteristic time for burnout of the movable fuel load, (b) the characteristic time for the occurrence of char fall-off, (c) the characteristic time for the occurrence of encapsulation failure, and (d) the heat exchange within the compartment after consumption of the moveable fuel. Self-extinction was attained only when the characteristic time for the occurrence of char fall-off was longer than the characteristic time for burn-out and the heat exchange after burn-out resulted in a heat flux below a well-defined threshold. The position of the exposed timber surfaces affected the magnitude of the threshold heat flux. If the characteristic time for burn-out was greater than the characteristic time for encapsulation failure, self-extinction was not observed to occur.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104346"},"PeriodicalIF":3.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143294211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Assessing the effect of oxidizer on flame geometry and effluent composition from burning solids","authors":"Jonathan Reep , José L. Torero , Rory M. Hadden","doi":"10.1016/j.firesaf.2025.104347","DOIUrl":"10.1016/j.firesaf.2025.104347","url":null,"abstract":"<div><div>The combustion chemistry and geometry of a diffusion flame are dictated by the transport of a fuel and an oxidizer towards a flame sheet. To enable the independent assessment of the impact of an oxidizer on a diffusion flame, the fuel injection rate must be controlled independently of the airflow. Through the independent control over the burning rate of the synthetic polymers polymethylmethacrylate (PMMA) and polyoxymethylene (POM), it is demonstrated that flame geometry can be systematically varied as a function of the oxygen environment. Both polymers were studied in the Fire Propagation Apparatus using a constant mass loss rate (MLR) under varying oxidative environments (177 L min<sup>−1</sup>, 0 – 20.9 % vol O<sub>2</sub>). This study draws upon frameworks developed for co-flow burners, allowing the characteristics of a diffusion flame to be established as a function of the oxidative environment. Flames sustained under lower oxidative environments displayed decreased luminosity and anchoring, with the heat flux from the POM flame decreasing by 14.7 kW m<sup>−2</sup> as the oxygen concentration decreased from 20.9 % to 9.25 %. By relating combustion emissions to the flame geometry, through the use of a constant MLR, the processes controlling the emissions from the burning of solids have been studied in a novel manner.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104347"},"PeriodicalIF":3.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Howard R. Baum , Michael A. Delichatsios, John L. de Ris , A. Carlos Fernandez-Pello, Marc Janssens, Richard E. Lyon, Vladimir Molkov, Arnaud Trouvé
{"title":"Prof. James G. Quintiere, a legend in fire safety science and engineering, dies at age 84","authors":"Howard R. Baum , Michael A. Delichatsios, John L. de Ris , A. Carlos Fernandez-Pello, Marc Janssens, Richard E. Lyon, Vladimir Molkov, Arnaud Trouvé","doi":"10.1016/j.firesaf.2025.104342","DOIUrl":"10.1016/j.firesaf.2025.104342","url":null,"abstract":"","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"152 ","pages":"Article 104342"},"PeriodicalIF":3.4,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143131312","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}