Fire, Volume 8, Issue 4 (April 2025) – 44 articles

Small-scale model experiments were conducted to examine the effectiveness of a point smoke exhaust system in an asymmetrical V-shaped tunnel. Using a design fire power of 20 MW as a reference, the study explored the optimal smoke exhaust rate for the point exhaust system in tunnels. Additionally, the impact of different slope combinations and various smoke vent opening configurations on the smoke control efficiency was analyzed when the fire source was positioned at the slope transition point of the V-shaped tunnel. The results indicate that an exhaust rate of approximately 140–160 m³/s is effective in controlling smoke for a 20 MW fire. In V-shaped tunnels, when three exhaust vents are symmetrically opened on both sides of the fire source, smoke diffusion on the large slope side remains uncontrolled. To address this issue, increasing the number of smoke exhaust vents on the large slope side can enhance smoke control. However, when the slope difference between the two sides of an asymmetrical V-shaped tunnel is excessively large—especially when the large side has a very high inclination—effective smoke control becomes significantly more challenging. Full article

Effective evacuation is vital for minimizing casualties during disasters. This study employed the Web of Science (WOS) database to perform a bibliometric analysis of the evacuation literature. VOSViewer (v1.6.20) and CiteSpace (v6.3.R1) software were used to visualize publication trends, international collaboration networks, keyword co-occurrence, clustering, and keyword bursts. The findings indicate that three research focuses are foundational to advancing the field of evacuation research, with shifts in these areas reflecting the dynamic nature of the field’s transition. Four key research themes outline the core content of the field’s investigation. Furthermore, this study identifies three key research phases in evacuation: the theoretical model development and foundational research phase, the behavioral dynamics and advanced simulation phase, and the data-driven intelligence and practical application phase. Future directions of evacuation research are discussed. This study provides a comprehensive analytical framework that deepens the understanding of the evacuation field. Full article

Wildfires, a natural part of the wildland life cycle, are experiencing a decades-long trend of increased frequency, duration, and magnitude, resulting in increased risk of fatalities and property damage. Fire suppression methods are adapting accordingly, including the increased use of aerial firefighting. Aerial firefighting, conducted in coordination with ground crews, provides real-time reconnaissance of a wildfire and performs strategic drops of retardant to contain and/or suppress the fire. These flight operations require airport and air traffic control infrastructure. The purpose of this report is to provide statistics on the U.S. aerial firefighting fleet, flight operations, and airport utilization and equipment in 2024. This information, which is not readily available, may be of use to airport planners, air navigation service providers, and policy makers. Thirty-four (34) Very Large/Large Air Tankers (VLAT/LATs) were under contract with the United States Forest Service (USFS) Multiple Award Task Order Contracts (MATOCs) in 2024. The aircraft, ranging in age from 27 to 57 years, performed 11,219 retardant drop and reposition flights. Flights operated on 88% of the days with an average of 35 flights per day and a maximum of 200 flights per day. The number of flights per aircraft across the fleet was not uniform (average 288 flights, max 465 flights). Consistent with firefighting practices, the flights operated under Visual Flight Rules (VFR), mostly in the afternoons, with an average retardant drop flight duration of 34 min. Two hundred and seven (207) airports supported at least one departure, with 14 airports supporting 50% of the departures. Eighty-six (86%) percent of the airports were towered and 84% had precision approach procedures. All but two military airports were public airports that are part of the National Plan for Integrated Airport System (NPIAS) and eligible for Airport Improvement Plan (AIP) funding. Runway length and weight bearing are limitations at several airports. Furthermore, operations are no longer limited to airports west of the Rockies, with increased operations in the mid-west and east coast. Full article

Battery electric buses (BEBs) are widely regarded as a safe and sustainable alternative to internal combustion vehicles. However, the lithium-ion batteries that power them present safety risks. This paper provides a comprehensive overview of the safety of battery electric buses, highlighting current challenges, relevant regulations and proposed solutions to enhance safety. There are significant shortcomings in the fire safety regulations for buses, especially concerning qualification methods for bus interiors. Enclosed spaces and structures represent the most critical risks for these transport systems. The presence of large vehicles, such as BEBs, in tunnels could increase the risk of transitioning from deflagration to detonation. Fires involving such vehicles produce more soot than fires from internal combustion engine buses (ICEBs) and have slightly higher toxicity levels. High-pressure water spraying systems are not yet an effective solution, as not all the heat is removed if the thermal runaway has already been triggered for several minutes, and their action remains largely limited to the outside of the battery pack. Another critical issue is cybersecurity. Managing and protecting BEBs from cyber threats is complex and requires robust strategies. Full article

The objective of this study was to understand the characteristics of gas migration in a mine system network domain during a period of reversal ventilation. Combining field experiments with the TF1M3D simulation program, we analyzed gas migration and distribution during reversal ventilation in the JIU LI coal mine. The results showed that, after implementation of the airflow reversal process for the entire mine, the gas in the return roadways flowed back to the working face and accumulated with the gas emitted from the working face to form a gas concentration peak, after which the gas concentration gradually decreased in a stepwise manner and finally reached a stable state that was maintained until the end of the reversal ventilation. The peak gas concentration and the peak areas of the gas concentration curve during the airflow reversal were positively correlated with the time of airflow stoppage operation. The gas concentration peak affected the safety of the mine airflow reversal process; therefore, countermeasures and technical plans should be made in advance. The TF1M3D simulation results were consistent with the field experiment results. Full article

Polylactic acid (PLA) is a biodegradable polymer served as thermal management material, and the heat transfer performance is closely related to its pore structure theoretically, but it is unclear how the structure affects its heat transfer. Therefore, a novel approach is proposed to address this issue by numerical simulations at low complexity and cost; three series of porous PLA are investigated with various structures in pore shape, size, and interval by fire dynamic simulation (FDS) and theoretical modeling, respectively. Meanwhile, the relationship between the hole structure and heat release rate (HRR) is developed by defining a new characteristic shape factor (Sc). It demonstrates that adjusting the pore structure of PLA significantly alters its heat transfer, evidenced by significant variations in HRR and smoke density. Additively, the approach for evaluating heat transfer is elucidated, encompassing the hole closure, vortex heat dissipation effect, and narrow variable speed effect. It provides some theoretical basis for designing porous thermal management materials. Full article

This study aims to evaluate the effectiveness of helicopters in fighting forest fires in Türkiye. The increasing frequency and severity of forest fires, especially with climate change, require more effective aerial response methods. Helicopters play a critical role due to their operational advantages, such as maneuverability, rapid access, and water-carrying capacity. In this study, the types of helicopters used in Türkiye are analyzed, and their operational efficiency is evaluated using Data Envelopment Analysis (DEA). The results reveal that certain models show high efficiency, but some helicopters have room for improvement in terms of fuel consumption and technical performance. A balanced use of both Bambi Bucket and internal water tank systems in fighting forest fires in Türkiye and investing in domestic production is recommended. Full article

Fire has been proven to threaten human lives and buildings significantly. Extensive research is being conducted globally to reduce fire risks, particularly in high-rise buildings that incorporate steel for structural support, timber for decorative elements, and cladding for insulation. Traditional passive fireproofing materials, such as concrete coverings, gypsum boards, and cementitious coatings, often lack aesthetic appeal. Intumescent coatings offer a promising solution to this issue. These coatings require a thin layer on the substrate to protect from fire, and the thin layer expands up to many times its original thickness when exposed to fire, forming an insulating char that acts as a barrier between fire and the substrate. This barrier prevents the steel from reaching critical temperature and helps maintain its integrity during a fire incident. Hence, intumescent coatings are a great choice for passive fire protection of load-bearing steel, wooden structures, timber, and cementitious buildings. Although some research articles discuss intumescent coating types, application methods, fabrication processes, cost-effectiveness, bonding performance, toxicity, and various uses, a comprehensive study encompassing all these topics still needs to be conducted. This review paper explores different types of intumescent coatings, their formulation and manufacturing methods, their application processes, and their use on various substrates. It also covers the key intumescent coating materials and their interactions during fire. Challenges and issues, such as fire protection time, char-forming temperature, and toxicity, are discussed. Full article

With the development of society and the advancement of technology, the application of electricity in modern life has become increasingly widespread. However, the risk of electrical fires has also significantly increased. This paper thoroughly investigates the causes, classifications, and challenges of electrical fires in special environments, and summarizes advanced detection and extinguishing technologies. The study reveals that the causes of electrical fires are complex and diverse, including equipment aging, improper installation, short circuits, and overloading. In special environments such as submarines, surface vessels, and aircraft, the risk of electrical fires is higher due to limited space, dense equipment, and difficult rescue operations. This paper also provides a detailed analysis of various types of electrical fires, including cable fires, electrical cabinet fires, transformer fires, battery fires, data center fires, and residential fires, and discusses their characteristics and prevention and control technologies. In terms of detection technology, this paper summarizes the progress of technologies such as arc detection, video detection, and infrared thermography, and emphasizes the importance of selecting appropriate technologies based on specific environments. Regarding extinguishing technologies, this paper discusses various means of extinguishing, such as foam extinguishing agents, dry powder extinguishing agents, and fine water mist technology, and highlights their advantages, disadvantages, and applicable scenarios. Finally, this paper identifies the limitations in the current field of electrical fire prevention and control, emphasizes the importance of interdisciplinary research and the development of advanced risk assessment models, and outlines future research directions. Full article

This study investigates the physical interactions and between forest fires and the atmosphere, which often lead to conditions favourable to instability and the formation of pyrocumulus (PyCu). Using the coupled atmosphere–fire spread modelling framework, WRF-SFIRE, the Portuguese October 2017 Quiaios wildfire, in association with tropical cyclone Ophelia, was simulated. Fire spread was imposed via burnt area data, and the fire’s influence on the vertical and surface atmosphere was analysed. Simulated local atmospheric conditions were influenced by warm and dry air advection near the surface, and moist air in mid to high levels, displaying an inverted “V” profile in thermodynamic diagrams. These conditions created a near-neutrally unstable atmospheric layer in the first 3000 m, associated with a low-level jet above 1000 m. Results showed that vertical wind shear tilted the plume, resulting in an intermittent, high-based, shallow pyroconvection, in a zero convective available potential energy environment (CAPE). Lifted parcels from the fire lost their buoyancy shortly after condensation, and the presence of PyCu was governed by the energy output from the fire and its updrafts. Clouds formed above the lifted condensation level (LCL) as moisture fluxes from the surface and released from combustion were lifted along the fire plume. Clouds were primarily composed of liquid water (1 g/kg) with smaller traces of ice, graupel, and snow (up to 0.15 g/kg). The representation of pyroconvective dynamics via coupled models is the cornerstone of understanding the phenomena and field applications as the computation capability increases and provides firefighters with real time extreme fire conditions or predicting ahead of time. Full article

Due to the high saturated vapor pressure of low-boiling-point flammable liquids, it is difficult to make fire extinguishers for storage tanks containing them. Air foam extinguishing technology has been recommended by several standards. However, the effectiveness of air foam against low-boiling-point flammable liquid is still limited due to a lack of experimental data. To validate the reliability of air foam, fire-extinguishing measures for three low-boiling-point flammable liquids including propylene oxide, n-pentane, and condensate oil were carried out for the first time in this work. The results show that air foam fails the fire extinguishment of the studied liquids even at higher supply intensities. To address the challenge of fire extinguishment in storage tanks containing low-boiling-point flammable liquids, a novel method using heptafluoropropane (HFC227ea) phase change foaming to substitute air was proposed in this work. The experimental system of HFC227ea foam fire extinguishment was constructed. In addition, two low-boiling-point flammable liquids propylene oxide and n-pentane were selected as the research subjects, the fire extinguishment measures were conducted. The results show that the proposed method can realize rapid and effective extinguishment of flames for the studied liquids. Full article

Peat fires generate significant greenhouse gas emissions, thereby posing considerable environmental challenges arising from smoke pollution, health hazards, and ecological impacts. Water alone is inefficient for extinguishing peat fires because it cannot immediately penetrate the soil. Therefore, firefighting agents with high penetrative capabilities are used. This study evaluated an environmentally friendly soap-based firefighting agent against peat fires in Palangka Raya, Indonesia. A 1.5 m × 1.5 m peat area was burned for 24 h to simulate a peat fire. The fire was then extinguished either with groundwater or a 1 vol.% soap-based firefighting agent solution. With groundwater, the volumes required to extinguish the fire were 16.0 and 23.9 L/m², whereas with the soap-based solution, the volumes used were 3.8 and 7.4 L/m². Furthermore, the time to extinguish the fire with the soap-based solution was approximately one-third of the requirement when using water alone. The soap-based firefighting agent was proven to be more effective against peat fires than water alone, reducing both the amount of agent used and the time required for extinguishing the fire. Given the increased severity of fires in recent years, this agent can facilitate the efficient management of peat fires. Full article

This study examines the impact of alcohol blends on the performance and emissions of aviation micro-turbojet engines. Thus, propanol, butanol, pentanol, hexanol, heptanol, and octanol were tested at 10%, 20%, and 30% concentrations and mixed with Jet A, as well as with an additional 5% heptanol blend to preserve base fuel properties, to fuel a JetCat P80 micro-turbojet. Physicochemical properties such as density, viscosity, and elemental composition were analyzed before engine testing. Carbon dioxide (CO₂) emissions from 1 kg of fuel combustion varied, with propanol yielding the lowest at 3.02 kg CO₂ per kg of fuel and octanol yielding the highest at 3.22 kg CO₂ per kg of fuel. The following results were obtained: alcohol blends lowered exhaust gas temperature by up to 7.5% at idle and intermediate thrust but slightly increased it at maximum power; fuel mass flow increased with alcohol concentration, peaking at 20.4% above Jet A for 30% propanol; and thrust varied from −4.92% to +7.4%. While specific fuel consumption increased by up to 12.8% for propanol, thermal efficiency declined by 1.8–5.6% and combustion efficiency remained within ±2% of Jet A. Butanol and octanol emerged as viable alternatives, balancing emissions reduction and efficiency. The results emphasize the need for an optimal trade-off between environmental impact and engine performance. Full article

We present a study that addresses the critical need for a prototype Decision Support System for forest fire information and management in Uttarakhand, India. The study’s main objective was to carry out statistical analysis of large fire incident datasets to understand trends of fires in the region and develop essential spatial decision support tools. These tools address the necessary fire management decision-making along with comprehensive datasets that can enable a decision maker to exercise better management. Moreover, this DSS addresses three major components of forest fire decision support: (i) pre-fire (forest information visualization) tools, (ii) during-fire terrain-based spatial decision support tools, and (iii) post-fire restoration tools. The efforts to develop this DSS included satellite lidar dataset-based fuel load estimations, the Keetch–Byram Drought Index, and the integration of spatial tools that ensure better spatial decisions in fire suppression planning. In addition, based on the bibliographic literature, the study also uses ecological and community-based knowledge, including financial aspects, for fire prevention and post-fire restoration planning. The development of this DSS involves an open-source R Shiny framework, enabling any decision maker at the execution or planning level to access these key datasets and simulate the spatial solutions cost-effectively. Hence, this study aimed to internalize key decision support tools and datasets based on extensive statistical analysis for data-driven forest fire planning and management. Full article

A high-temperature gas plasma scheme using methane/air/K₂CO₃ mixed combustion is proposed for the application background of hypersonic aircraft. The actual combustion temperature was calculated by ANSYS Chemkin Pro software; the various components of the combustion reaction were determined; and the function between temperature and electrical conductivity was established, revealing the variation law of ionization decomposition of K₂CO₃ ionized seeds with gas temperature. At 1500 K, K₂CO₃ ionized seeds are close to complete ionization. Increasing the mass fraction of K₂CO₃ ionized seeds will enhance the endothermic effect of K₂CO₃ seed ionization decomposition. Under the same residual gas coefficient conditions, the combustion equilibrium temperature will correspondingly decrease. The increase in initial combustion temperature results in an approximately linear increase in equilibrium temperature and conductivity. With the increase in initial pressure, the equilibrium temperature of gas shows a logarithmic growth trend, while conductivity gradually decreases and the gradient of change gradually slows down. This study provides a new method for evaluating the ionization characteristics of high-temperature gas plasma formed by potassium carbonate (K₂CO₃) as ionization seed, and hydrocarbon fuel (CxHy) combined with air. Full article

This study aimed to develop the Five Cognitive Biases in Risk-Taking Scale (5 CBR-S) to measure five cognitive biases associated with risk-taking: overconfidence, illusion of control, belief in the law of small numbers, escalation of commitment, and optimism. Firefighters completed a series of five questionnaires: cognitive biases related to risk-taking, emotional intelligence, self-regulation behaviors, personality traits, and mental toughness. Data were collected from two distinct samples, each consisting of 202 firefighters. A series of exploratory and confirmatory factor analyses conducted on an initial version of the 5 CBR-S with 50 items provided structural evidence supporting a 5-factor, 19-item solution. Evidence of validity and reliability for the 5 CBR-S scores was provided by examining correlations with emotional intelligence, personality traits, and mental toughness. Overall, despite certain limitations, the 5 CBR-S constitutes a robust measure, offering the advantage of highlighting the five main cognitive biases related to risk-taking. It can be used both among firefighters and in other professional contexts involving high-intensity emergency decision-making. Full article

Numerical simulations reveal the combustion dynamics of hydrogen-blended natural gas (H-BNG) in semi-open spaces. In the typical semi-open space scenario, increasing the hydrogen blending ratio from 0% to 60% elevates peak internal pressure by 107% (259.3 kPa → 526.0 kPa) while reducing pressure rise time by 56.5% (95.8 ms → 41.7 ms). A vent size paradox emerges: 0.5 m openings generate 574.6 kPa internal overpressure, whereas 2 m openings produce 36.7 kPa external overpressure. Flame propagation exhibits stabilized velocity decay (836 m/s → 154 m/s, 81.6% reduction) at hydrogen concentrations ≥30% within 2–8 m distances. In street-front restaurant scenarios, 80% H-BNG leaks reach alarm concentration (0.8 m height) within 120 s, with sensor response times ranging from 21.6 s (proximal) to 40.2 s (distal). Forced ventilation reduces hazard duration by 8.6% (151 s → 138 s), while door status shows negligible impact on deflagration consequences (412 kPa closed vs. 409 kPa open), maintaining consistent 20.5 m hazard radius at 20 kPa overpressure threshold. These findings provide crucial theoretical insights and practical guidance for the prevention and management of H-BNG leakage and explosion incidents. Full article

The new eco-friendly flammable refrigerant in air conditioners has resulted in an annual increase in fire incidents associated with these units. Fire investigators face significant challenges in identifying the causes of these fires. In this study, copper tube samples were extracted from various locations of air conditioner condenser debris post fire. The morphology characteristics of the ruptured copper tubes formed by a high-temperature flame in fire and that formed by corrosion were analyzed, respectively. The findings indicate that the ruptures in the copper tubes of air conditioners may be classified into two types based on their origins: ruptures resulting from fire and ruptures resulting from corrosion. The ruptures in the copper tubes resulting from fire are associated with the presence of aluminum alloy fins. At elevated temperatures, the copper and aluminum atoms persist in diffusing and fracturing. A significant quantity of silver-white aluminum is present surrounding the ruptures, and distinct elemental layers may be seen in the cross-section. The corrosion-induced ruptures in the copper tubes are associated with ant nest corrosion. Despite the influence of high-temperature flame melting on surface corrosion pits, they will not entirely obscure the pits and the cross-section continues to exhibit the bifurcated structure characteristic of ant nest corrosion. This investigation demonstrates that corrosion of ant nests is the root cause of copper tube breakage obscured by flames. An investigation method for the refrigerant leakage air conditioning fire is proposed. The above findings can provide proof and method for air conditioning fire investigation. Full article

In this study, we investigated the influence of pre-fire tree mortality on fire behavior. Although other studies have focused on the environmental factors affecting wildfire, the influence of pre-fire tree mortality has not been explored in detail. We used high-spatial-resolution (1.6 m) airborne multispectral orthoimages to detect and map pre-fire dead trees in a portion of the San Bernardino Mountains, where the ‘Old Fire’ burned in 2003, and assessed whether spatial patterns of fire intensity and burn severity coincide with patterns of tree mortality. Dead trees were mapped through a hybrid deep learning classification and manual editing approach and facilitated with Google Earth Pro historical images. Apparent thermal infrared (TIR) brightness temperature captured during the Old Fire was derived from maximum digital number values from FireMapper airborne thermal infrared imagery (7 m) as a measure of fire intensity. Burn severity was analyzed using normalized burn ratio maps derived from pre- and post-fire Landsat 5 satellite imagery (30 m). Pre-fire dead trees were prevalent with 192 dead trees and 108 live trees per ha, with most dead trees clustered near the northwestern part of the study area east of Lake Arrowhead. The degree of spatial correspondence among dead tree density, fire intensity, and burn severity was analyzed using graphical and statistical analyses. The results revealed a significant but weak spatial association of dead trees with fire intensity (R² = 0.31) and burn severity (R² = 0.14). The findings revealed that areas impacted by pre-fire tree mortality were subject to higher fire intensity, followed by severe burn effects, though other biophysical factors also influenced these fire behavior variables. These results contradict a previous study that found no effect of tree mortality on the behavior of the Old Fire. Full article

Mountain photovoltaic (PV) power stations cover vast areas and contain dense equipment. Once direct current arc faults occur in PV modules, they can pose a serious thermal threat to surrounding facilities and combustible materials, potentially resulting in a PV array fire accident. In this work, a series of PV module fire experiments were conducted to investigate the burning characteristics of PV modules exposed to the pool fire. The burning process, burning damage extent, and temperature distribution were measured and analyzed. The results showed that the surfaces of PV modules exhibited different burning characteristics due to the pool fire. Based on different characteristics, the front side was classified into four zones: intact zone, delamination zone, carbonization zone and burn-through zone. The back side was similarly divided into four zones: undamaged backsheet zone, burnt TPT zone, cell detachment zone and burn-through zone. Meanwhile, the burning process and surface temperature rise rate of intact PV modules were significantly lower than those of cracked modules at the same inclination angle. Cracked modules exhibited a heightened susceptibility to being rapidly burnt through by the pool fire. As the inclination angle increased from 0° to 60°, the burning damage extent and the expansion rate of high-temperature regions initially ascended and subsequently decreased, reaching their maximum at the inclination angle of 15°. These findings can offer valuable insights that can serve as a reference for the fire protection design and risk assessment of mountain PV power stations, ensuring their safe operation. Full article

The increasing frequency and severity of agricultural fires pose significant threats to food security, economic stability, and environmental sustainability. Traditional fire-detection methods, relying on satellite imagery and ground-based sensors, often suffer from delayed response times and high false-positive rates, limiting their effectiveness in mitigating fire-related damages. In this study, we propose an advanced deep learning-based fire-detection framework that integrates the Single-Shot MultiBox Detector (SSD) with the computationally efficient MobileNetV2 architecture. This integration enhances real-time fire- and smoke-detection capabilities while maintaining a lightweight and deployable model suitable for Unmanned Aerial Vehicle (UAV)-based agricultural monitoring. The proposed model was trained and evaluated on a custom dataset comprising diverse fire scenarios, including various environmental conditions and fire intensities. Comprehensive experiments and comparative analyses against state-of-the-art object-detection models, such as You Only Look Once (YOLO), Faster Region-based Convolutional Neural Network (Faster R-CNN), and SSD-based variants, demonstrated the superior performance of our model. The results indicate that our approach achieves a mean Average Precision (mAP) of 97.7%, significantly surpassing conventional models while maintaining a detection speed of 45 frames per second (fps) and requiring only 5.0 GFLOPs of computational power. These characteristics make it particularly suitable for deployment in edge-computing environments, such as UAVs and remote agricultural monitoring systems. Full article

Understanding environmental factors that control the ignition of fuel beds exposed to firebrands is necessary to help reduce the risk of losses of structures. Ignition by firebrands has been reported to be sensitive to wind, but identification and quantification of the physical cause(s) of such sensitivities are still limited. The objective of this study was to quantify the influence of wind speed and direction on the ignition of a fuel bed exposed to firebrands and to understand the causes of this sensitivity. Fuel beds of Douglas fir shavings were exposed to a firebrand surrogate (i.e., a resistive heater) to determine flaming ignition probability and time to ignition for three different wind speeds and three wind directions. Increases in wind speed above quiescent reduced the temperature required for flaming ignition. However, a wind speed threshold above which ignition probability decreased was observed for some wind directions. The temperatures required for flaming ignition to occur and the time to ignition were sensitive to the wind direction. High-speed images and corresponding CFD calculations indicated that ignition occurred in the regions with the most prominent recirculation zones. Thus, sensitivities to wind speed and direction are attributable to differences in the pyrolysate residence time as controlled by recirculation zones. The results indicate that the local flow characteristics can significantly influence ignition, and characterization of the freestream velocity alone may not be sufficient. Full article

This study investigates the behaviour of plumes from massive fires subjected to crosswinds, focusing on how varying wind profiles and terrain characteristics influence the formation of coherent vortical structures, particularly wake vortices, and the smoke distribution in the near-fire region. Large Eddy Simulations (LES) were employed to model the interaction between the plume, generated by a rectangular fireline with an intensity of $40\mathrm{MW}/\mathrm{m}$, and the crosswind. Upon the consideration of several wind intensities (from 5 to $10\mathrm{m}/\mathrm{s}$) and vertical distributions, it was verified that only for relatively low average wind velocities was there significant lateral entrainment to the flame, which promoted the formation of vertical vortical structures. Depending on the vertical distribution of the wind, different mechanisms can play a role in the formation of these structures, with a larger number of mechanisms involved for the cases where there is very low near-wall wind momentum, typical of large vegetation regions. The slope of the terrain (from $-{20}^{\circ }$ to $+{20}^{\circ }$) plays a role in these relations since it affects the fire plume inclination and, consequently, the entrainment process. These structures are more likely to appear in downslope terrains. Full article

The wind and slope are deemed to be the determinant factors driving the extreme or erratic spread behavior of wildfire, which, however, has not been fully investigated, especially to elaborate the mechanism of fire spread associated with heat transfer and fluid dynamics. A systematic study is therefore carried out based on a physical-based simulation and proper orthogonal decomposition (POD) analysis. Results show that compared to the wind, the slope plays a more profound effect on the fire structure; with the increase in slope, the fire line undergoes a transition from a W-shape to the U- and pointed V-shape, accompanied by stripe burning zones, indicating a faster spread but incomplete combustion. The wind effect is distinguished by mainly inducing a turbulent backflow ahead of the fire front, while the slope effect promotes convective heating via the enhanced slant fire plume. Different mechanisms are also identified for the heat transfer ahead of the fire line, i.e., the radiative heat is affected by the combined effects of the flame length and view angle, and in contrast, the convective part of the heating flux is dominated by the action of the flame attachment, which is demonstrated to play a crucial role for the fire spread acceleration at higher slopes (>20°). The POD analysis shows the distinct pattern of flame pulsating for the respective wind and slope effects, which sheds light on modeling the unsteady features of fire spreading and reconfirms the necessity of considering the different effects of these two environmental factors. Full article

Forest fires have a great destructive impact on the Earth’s ecosystem; therefore, the top priority of current research is how to accurately and quickly monitor forest fires. Taking into account efficiency and cost-effectiveness, deep-learning-driven UAV remote sensing fire detection algorithms have emerged as a favored research trend and have seen extensive application. However, in the process of drone monitoring, fires often appear very small and are easily obstructed by trees, which greatly limits the amount of effective information that algorithms can extract. Meanwhile, considering the limitations of unmanned aerial vehicles, the algorithm model also needs to have lightweight characteristics. To address challenges such as the small targets, occlusions, and image blurriness in UAV-captured wildfire images, this paper proposes an improved UAV forest fire detection model based on YOLOv8. Firstly, we incorporate SPDConv modules, enhancing the YOLOv8 architecture and boosting its efficacy in dealing with minor objects and images with low resolution. Secondly, we introduce the C2f-PConv module, which effectively improves computational efficiency by reducing redundant calculations and memory access. Thirdly, the model boosts classification precision through the integration of a Mixed Local Channel Attention (MLCA) strategy preceding the three detection outputs. Finally, the W-IoU loss function is utilized, which adaptively modifies the weights for different target boxes within the loss computation, to efficiently address the difficulties associated with detecting small targets. The experimental results showed that the accuracy of our model increased by 2.17%, the recall increased by 5.5%, and the mAP@0.5 increased by 1.9%. In addition, the number of parameters decreased by 43.8%, with only 5.96M parameters, while the model size and GFlops decreased by 43.3% and 36.7%, respectively. Our model not only reduces the number of parameters and computational complexity, but also exhibits superior accuracy and effectiveness in UAV fire image recognition tasks, thereby offering a robust and reliable solution for UAV fire monitoring. Full article

Current research on fires in high-speed train carriages mainly focuses on the temperature distribution of smoke, while the flow structure and dynamic evolution patterns of smoke have not been reviewed. This study employs numerical simulation to systematically investigate the fire ejection behavior from broken windows of a high-speed train carriage, and the influence of different broken window parameters was considered. The research results indicate that the asymmetric geometric configuration of seats on both sides of the fire source induces a lateral displacement of fire smoke toward the downstream direction due to the sidewall effect, resulting in an asymmetrical distribution of smoke flow velocity and temperature within the compartment. Compared to fire scenarios with one broken window, the presence of broken windows on both sides increases the number of smoke dispersion outlets, leading to a significant rise in smoke flow velocity around the fire source. In the aisle region far from the fire source, the smoke flow velocity decreases, consequently lowering the compartment temperature. Compared with the case of one broken window, the aisle temperature decreased by 83 K in the case of two broken windows. When the broken window is located farther from the fire source, smoke tends to accumulate extensively within the compartment before being discharged through the broken windows, which enhances the longitudinal smoke flow velocity and elevates the compartment temperature. When a window far from the fire source is breached, the temperature in the aisle increases by 270 K compared to when a window in the middle of the carriage is breached. Full article

Experience is crucial for enhancing task performance. However, rescue experience, as a key contributor to individual and team capabilities within fire brigades, has not received sufficient attention in fire safety management research. Based on the concept of shared team task-specific (STTS) experience, this study explored how it affects the rescue effectiveness of fire brigades. To test the proposed model, data were collected from a sample of 452 firefighters in China. The results indicated that STTS experience, including both task-specific experience and shared team experience, significantly improves the rescue effectiveness of fire brigades. Moreover, shared mental models, including both teammate mental models and task mental models, mediate the relationship between STTS experience and rescue effectiveness, while team tenure strengthens the effect of STTS experience on shared mental models and subsequent team performance. These findings enhance the understanding of fire brigade performance and contribute to improving emergency rescue effectiveness. Theoretical and practical implications, limitations, and future research directions are provided and discussed. Full article

Accurate wildfire spread modeling critically depends on the representation of wind dynamics, which vary with terrain, land cover characteristics, and height above ground. Many fire spread models are often coupled with coarse atmospheric grids that cannot explicitly resolve the vertical variation of wind near flame heights. Rothermel’s fire spread model, a widely used parameterization, relies on midflame wind speed to calculate the fire rate of spread. In coupled fire atmosphere models such as the Community Fire Behavior Model (CFBM), users are required to specify the midflame height before running a fire spread simulation. This study evaluates the use of logarithmic interpolation wind adjustment factors (WAF) for improving midflame wind speed estimates, which are critical for the Rothermel model. We compare the fixed wind height approach that is currently used in CFBM with WAF-derived winds for unsheltered and sheltered surface fire spread. For the first time in this context, these simulations are validated against satellite and ground-based observations of fire perimeters. The results show that WAF implementation improves fire perimeter predictions for both grass and canopy fires while reducing the overestimation of fire spread. Moreover, this approach solely depends on the fuel bed depth and estimation of canopy density, enhancing operational efficiency by eliminating the need for users to specify a wind height for simulations. Full article

Tunnel fires pose significant challenges to public safety due to their rapid development and the confined nature of tunnel environments. Traditional fire detection systems often struggle with delayed response times and high false alarm rates, particularly in complex scenarios. This study proposes a lightweight hybrid deep learning (DL) model that integrates Convolutional Neural Networks (CNNs) for spatial feature extraction and Long Short-Term Memory (LSTM) networks for temporal analysis, offering an efficient and robust solution for real-time tunnel fire detection. Leveraging transfer learning, the model adapts to tunnel-specific fire scenarios with minimal training data, significantly improving its generalization capabilities. The lightweight architecture ensures computational efficiency, making it suitable for deployment in resource-constrained environments such as tunnels with limited processing capacity. The model was rigorously evaluated on datasets combining simulated and real-world fire scenarios. It achieved an accuracy of 92%, a precision of 89%, a recall of 90%, and an F1 score of 89.5%, outperforming state-of-the-art (SOTA) models in all key metrics. Furthermore, the model demonstrated resilience under varied environmental conditions, including high smoke density and sensor failures, maintaining reliable performance. This study highlights the potential of lightweight deep learning models in enhancing tunnel safety systems by providing accurate, fast, and dependable fire and smoke detection. Future work will extend the methodology to other critical infrastructures and optimize the model for broader applications. Full article

A significant number of UK fire fatalities have been reported to involve textiles contaminated with emollients. In the following study, the flammability of a variety of fabrics containing 14 different emollients, including paraffin-free creams, was evaluated. This is the first time the impact of the presence of such a large range of emollients has been examined. Horizontal burn tests were conducted on emollient-contaminated fabrics. Significantly earlier ignition time were noted upon heating for all emollient-contaminated fabrics (p < 0.001) when compared to the behaviour of blank fabrics were noted using a vertical burn test. The mean time to ignition for 100% cotton fabric (151 ± 2 g/m²) was reduced from 71.5 to 14.4 s and for 52%/48% polyester/cotton fabric (103 ± 2 g/m²) from 328 to 12.9 s by the presence of emollients. Horizontal burn tests with a direct flame on 100% cotton fabric (114 ± 1 g/m²) displayed an accelerated mean flame speed from 0.0032 to 0.0048 ms⁻¹ and an increased maximum flame height of 56.6 to 175.4 mm for emollient-contaminated fabrics. These findings demonstrate the fire risk of fabrics contaminated with a dried emollient. Their potential to ignite quickly and to propagate a fire may strongly decrease the reaction time of an impacted individual. Therefore, it is important that this risk and appropriate safety advice be continually highlighted and communicated not only in the UK but worldwide. Full article