Search Results (209)

Wildfires increasingly threaten human life, ecosystems, and infrastructure, with events like the 2025 Palisades and Eaton fires in Los Angeles County underscoring the urgent need for more advanced prediction frameworks. Existing physics-based and deep-learning models struggle to capture dynamic wildfire spread across both 2D and 3D domains, especially when incorporating real-time, multimodal geospatial data. This paper explores how generative artificial intelligence (AI) models—such as GANs, VAEs, and transformers—can serve as transformative tools for wildfire prediction and simulation. These models offer superior capabilities in managing uncertainty, integrating multimodal inputs, and generating realistic, scalable wildfire scenarios. We adopt a new paradigm that leverages large language models (LLMs) for literature synthesis, classification, and knowledge extraction, conducting a systematic review of recent studies applying generative AI to fire prediction and monitoring. We highlight how generative approaches uniquely address challenges faced by traditional simulation and deep-learning methods. Finally, we outline five key future directions for generative AI in wildfire management, including unified multimodal modeling of 2D and 3D dynamics, agentic AI systems and chatbots for decision intelligence, and real-time scenario generation on mobile devices, along with a discussion of critical challenges. Our findings advocate for a paradigm shift toward multimodal generative frameworks to support proactive, data-informed wildfire response. Full article

In the actual installation of cables, inclined cable laying within covered cable trays is a relatively common method. To investigate the effects of different tilt angles on the combustion behavior of cables within covered cable trays, aluminum conductor polyethylene-insulated power cables were used as the test cables. The flame morphology, temperature distribution, and fire spread rate during the cable combustion process were analyzed for experimental scenarios for which the cable laying angles and the ignition positions changed. The results indicate that the inclination angle of the covered cable tray has a significant impact on flame propagation and temperature distribution. For the ignition located at the lowest part of the cable, the fire spread rate increases significantly with the tilt angle. In contrast, for the ignition located at the highest part of the cable, the fire spread rate initially decreases slightly and then increases, with a relatively smaller overall change in magnitude. Under both ignition positions, the flame spread rate significantly increases at 15–30°. Therefore, in actual cable installation processes, cables within covered troughs should avoid large-angle inclinations. Full article

Due to the unique physicochemical properties of ammonia fuel, any leakages in the engine room will inevitably endanger ship safety. This study focuses on investigating the diffusion behavior of ammonia fuel within the engine room during ship navigation after leakage, aiming to identify hazardous points and implement measures, such as installing air-blowing and extraction devices, to mitigate the risks. To address potential leakage risks in ammonia-fueled ships, a simplified three-dimensional computational model was developed based on ship design drawings and field investigations. ANSYS Fluent software (2024 R2) was employed to simulate ammonia fuel leakage from pipelines and equipment, analyzing the diffusion patterns of leakage at different locations and evaluating the impact of adding air-blowing and extraction devices on leaked fuel in the engine room. The simulation results demonstrate that leakage at point 3 poses the greatest operational hazard, and ammonia fuel leakage during navigation generates combustible gas mixtures within the explosion limit range around the main engine, severely threatening both vessel safety and crew lives. Installing air-blowing and extraction devices in high-risk areas effectively reduces the explosion limit range of ammonia fuel, with air outlet 3 showing optimal mitigation effectiveness against ammonia fuel leakage during ship transportation. Full article

Experimental measurements of midwave infrared thermal images of methane diffusion flames at different concomitant flow velocities were obtained as snapshot data to analyze the flame scintillation effect. The spectral proper orthogonal decomposition (SPOD) method was used to extract the frequency-spectral features of the flame to characterize the effect of the co-flow on the flame scintillation characteristics. The results show that, under the effect of the Kelvin-Helmholtz instability, a rolled-up vortex structure is formed within the shear layer, which triggers periodic flickering during flame combustion. The frequency-spectral characteristics of the flickering phenomenon corresponding to unstable combustion show an octave distribution. An increase in the co-flow velocity leads to an increase in the peak flicker frequency. The peak frequency was 11.6 Hz in the case without associated flow and 16.6 Hz in the case with associated flow. The SPOD analysis results indicated that the high-frequency first-order modes dominated by the flickering phenomenon exhibited an axisymmetric distribution, whereas the second-order modes exhibited an antisymmetric distribution. In contrast, the low-frequency first-order modes exhibit an antisymmetric distribution, whereas the second-order modes exhibit an axisymmetric distribution. Full article

Fire safety solutions for buildings in Slovakia are addressed by legislation and Slovak technical standards, which are not legally binding, but their wording is mandatory if they are referred to in an implementing regulation. Fire safety solutions for buildings in Slovakia are therefore limited mainly by legislation and technical standards. The use of fire models in fire safety solutions for buildings is common across the world, but these tools are not used in Slovakia. Their use is not prohibited by law, but it is always necessary to prove the applicability and correctness of the outputs. The paper deals with a case study of Slovak implementation of fire models when discussing the stand-off distances from fully fire-open areas. The Slovak case study addresses the fire safety solutions for buildings under the conditions of the Slovak Republic. To utilize the fire models in practice, the threshold conditions for the use of the selected FDS fire model needed to be established. This process is called a sensitivity analysis, and it is conducted based on the utilized simulation method. Based on the sensitivity analysis of FDS, the exact values of parameters can be determined, the use of which in the implementation of fire models in practice will allow accurate outputs and values of stand-off distances from fully fire-open areas in the conditions of the Slovak Republic to be obtained. Full article

Lithium-ion batteries (LIBs) have come to hold ever greater significance across diverse fields. However, thermal runaway and associated fire incidents have undeniably constrained the application and development of LIBs. Consequently, gaining a profound understanding of the reaction mechanisms of LIB electrolytes during thermal runaway is of critical importance for ensuring the fire protection of LIBs. In this study, quantum chemical calculations were employed to construct oxidation reaction models of electrolytes, and a comprehensive summary of the sources of fire gas generation during the thermal runaway of LIBs is presented. During the sequence of oxidation reactions, the -COH functional group emerged as the most critical intermediate product. Under conditions of low oxygen availability, it was prone to decompose into CO, whereas in the presence of sufficient oxygen, it could undergo further oxidation to form -COOH and subsequently decompose into CO₂. Moreover, the reaction chains associated with electrolyte oxidation were found to be highly intricate, characterized by multiple branches and a wide variety of intermediate products. Furthermore, an in-depth analysis was carried out on the generation mechanisms of several typical fire gases. The analysis revealed that CH₃OH and C₂H₅OH could be considered as the characteristic products of the oxidation reactions of DMC and DEC, respectively. It is anticipated that this research will provide a robust theoretical foundation for elucidating the complex reactions involved in LIB fires and offer reaction models for fire simulation purposes, thereby contributing to the enhancement of the safety and reliability of LIBs in various applications. Full article

Here, a pure and systematic numerical study is conducted to investigate the detonation propagation in a curvature bend by focusing on the combined effect of curvature and cross-section area with a simple two-step chemical reaction model. In a channel with a small radius of curvature R/λ < 10, the detonation wave presents a periodical failure-reinitiation mode. The detonation wave near the inner wall cannot sustain itself due to the strong curvature effect. In contrast, the compression of the outer wall strengthens the front and can form a transverse detonation wave to re-initiate the failed detonation near the inner wall. In a channel with a large radius of curvature R/λ > 10, the inner wall’s weak rarefaction effect is not strong enough to completely quench the detonation wave. In the same way, the numerical results also show that a large area expansion rate inevitably produces a strong rarefaction effect near the inner wall, causing wave front decoupling and even failure. According to the radius of the curvature and the area increase rate, there are three different modes of detonation propagation: stable, critical, and unstable. By defining a new parameter κ to characterize different detonation modes and by considering both the curvature and area expansion effect, we found that the threshold κ = 0.33 can be used to distinguish the unstable and critical modes. Full article

At 2:54 A.M. on 14 October 2021, a devastating fire erupted in a high-rise building in Kaohsiung City, Taiwan, involving 12 floors above ground and a basement level, resulting in 46 fatalities and 41 injuries. The official investigation pinpointed regulatory deficiencies and negligence among relevant department officials. The persistence of major fires globally underscores that merely relying on post-incident investigation reports is insufficient to fully uncover the underlying problems, highlighting the complexity of fire-related systemic challenges. This study adopts a systems thinking approach and synthesizes findings from various sources, including the investigation reports of this fire and the Grenfell Tower fire, research on fatal fires, and literature on high-rise building fires. It examined the systemic issues related to fires from three angles: resident characteristics, building factors, and situational factors. The analysis exposes the deep complexity of fire-related systemic problems and the interconnections among various contributing elements. Comprehensive initiatives that span educational, legislative, policy, and economic domains must be launched to reduce the frequency of fires and enhance survival rates. The insights from this study offer a profound understanding of the fundamental problems associated with fires and aim to inform strategies to prevent similar tragedies in the future. Full article

Penetration points on walls must include firestop measures to prevent the spread of fire. Countries worldwide have established standardized testing protocols for firestop methods, and firestop products must pass relevant tests before they can be used in buildings. In the present study, a simple method was developed to enhance the smoke leakage performance and fire resistance of existing polyvinyl chloride (PVC) pipes passing through walls. Two sets of smoke leakage tests were performed, followed by two sets of fire tests. The smoke leakage tests were nondestructive and thus did not damage the specimens; consequently, the same specimens could be used in the smoke leakage and fire tests. The results of the smoke leakage tests indicate that the method using PVC pipes wrapped with galvanized steel sleeves outperforms the method without such wrapping. Moreover, the results of the fire tests suggest that galvanized steel sleeves considerably improve thermal insulation and safety. This finding is explained as follows: PVC pipes may burn and break apart at high temperatures, compromising fire compartmentation. A galvanized steel sleeve can retain a burning, broken pipe piece, thereby preventing injuries and stopping the detached pipe from continuing to burn on the ground. Full article

In order to ensure the safety of methane/hydrogen, regular SiO₂ powder was modified. Fe(C₅H₅)₂/SiO₂ composite dry powder (CDP) was selected as the explosion-suppression material. Explosion-suppression experiments and numerical simulations were adopted to investigate the inhibition effect of 0% (${\mathit{X}}_{{\mathrm{H}}_2}$ = 0%) and 20% (${\mathit{X}}_{{\mathrm{H}}_2}$ = 20%) hydrogen doping ratios. The flame structure, flame propagation speed, and maximum explosion pressure are depicted to compare the inhibition effect of different mass fractions (X_Fe(C5H5)2 = 0–6%). The results showed that CDP significantly reduced the flame propagation velocity and maximum explosion pressure of ${\mathit{X}}_{{\mathrm{H}}_2}$ = 0%. The best effect was observed when 6% Fe(C₅H₅)₂ was added, with the velocity reduced to 9.241 m/s. The maximum explosion pressure was reduced to 0.518 MPa, and the effect was relatively weak for ${\mathit{X}}_{{\mathrm{H}}_2}$ = 20%, with the maximum pressure reduced to 0.525 MPa. In addition, the key radical production and temperature sensitivity showed that Fe(C₅H₅)₂ altered the molar fractions of the major species and increased the consumption of •H, •O, and •OH. As the mass fraction of Fe(C₅H₅)₂ increased, the steady-state concentrations of •H, •O, and •OH in the system showed a significant decreasing trend. This phenomenon originated from the two-step synergistic mechanism of Fe(C₅H₅)₂ inhibiting radical generation and accelerating radical consumption. This study provides insight into the process of Fe(C₅H₅)₂/SiO₂ composite dry powder inhibition and renders theoretical guidance for the explosion protection of methane/hydrogen. Full article

Recent trends of intense forest fires in the Korean Peninsula have increased concerns about more extreme burning in the future under a warming climate. Accurate and reliable fire weather information has become more critical to reduce the risk of forest-related disasters over complex terrain. In this study, two parameterizations reflecting complex topographic effects were implemented in the Weather Research and Forecasting (WRF) model. The model performance was evaluated over the mountainous region in Gangwon-do, South Korea’s most significant forest area. The simulation results of the wildfire case in 2019 show that subgrid-scale orographic parameterization considerably improves model performance regarding wind speed, with a lower root mean square error (RMSE) and bias by 53% and 57%, respectively. Another parameterization, reflecting slope and shading, effectively reflected sunrise and sunset effects. The second parametrization produced little effect on the daily averages of meteorological elements. However, thermodynamic components such as temperature and heat flux show more realistic values during sunset or sunrise when the solar altitude angle is low. The results imply that applying topographic parameterizations is required in numerical simulations, especially for hazardous weather conditions over complex terrain in mountainous regions. Full article

The primary atomization of planar liquid sheets near nozzle exits plays a critical role in the study of pressure-swirl atomizers, yet its intrinsic destabilization and breakup mechanisms remain insufficiently characterized due to the multi-scale nature of gas–liquid interactions, significantly limiting the predictive capacity of current widely adopted atomization models. This study utilizes three-dimensional direct numerical simulations (DNSs) with adaptive mesh refinement and the Volume-of-Fluid (VOF) method to examine the instability and disintegration of a spatially developing planar liquid sheet under operating conditions representative of aero-engine combustors (thickness $h=100 \mathsf{\mu }\mathrm{m}$, $We=2544$, $Re=886$). Adaptive grid resolution (minimum cell size $2.5 \mathsf{\mu }\mathrm{m}$) enables precise resolution of multi-scale interface dynamics while maintaining mass conservation errors below 0.1‱. High-fidelity simulations reveal distinct atomization cascades originating from the jet tip, characterized by liquid sheet roll-up, interface expanding, interface tearing, and ligament/droplet formation. Through extraction and surface characterization of representative shed liquid ligaments, we quantify temporal and spatial variations between ligaments propagating toward and away from the jet core region. Key findings demonstrate that ligament impingement on the liquid core serves as the dominant mechanism for surface wave destabilization, surpassing the influence of initial gas–liquid shear at the nozzle exit. Spectral analysis of upstream surface waves reveals a pronounced correlation between high-wavenumber disturbances and the mean diameter of shed ligaments. These results challenge assumptions in classical atomization models (e.g., LISA) by highlighting self-destabilization mechanisms driven by droplet–ligament interactions. This work provides critical insights for refining engineering atomization models through physics-based ligament diameter prediction criteria. Full article

A series of experiments were conducted on quartz sand beds wetted with transformer oil under initial temperatures of 80–140 °C and fuel–sand mass ratios of 1:4–1:8. The flame spreading process over the fine sand bed wetted with limited liquid fuel can be divided into the development and quasi-steady stages. Experimental results reveal that the flame spread rate in the quasi-steady stage increases with the initial temperature and fuel–sand mass ratio. The effect of sand bed width on flame spread depends on the initial temperature. The flame spread rate is insensitive to the sand bed width at low initial temperatures; however, it increases with sand bed width at an initial temperature close to the flash point of liquid fuel. This discrepancy mainly results from the enhanced capillary effect due to the decreased viscosity at high initial temperatures. The capillary effect is the dominant factor determining fuel vaporization and, thus, the flame spread rate, and flame radiation plays an increasing role with increasing initial temperature. The maximum flame height is sensitive to sand bed width and fuel–sand mass ratio but changes little with initial temperature. A dimensionless model was proposed to predict the normalized flame height. Full article

Fire safety is one of the critical concerns for the design and construction of modular structures. The lack of understanding of cavity fire spread in modular construction could create variations in the fire performance of structural members. This study aimed to assess the impact of cavity fire spread in modular buildings initiated by a room fire using validated fire dynamics and structural numerical models. A comprehensive parametric study was conducted to identify critical thermal conditions affecting adjacent structural members under plausible cavity fire scenarios. The identified critical cavity fire thermal conditions were used to examine the structural performance of cold-formed steel intermediate column specimens while varying geometric configurations, material properties, and boundary conditions. The results highlighted two distinct phases of restrained thermal expansion and lateral deformations under material yielding and buckling, resulting in the loss of structural integrity. The restrained thermal expansion significantly increased axial/restraint forces, reaching up to 155% of the initial load. This behavior decreased axial load capacity by 2.4% to 35% of the ambient capacity. Further, the study identifies a requirement for designing the intermediate columns and the connected intermodular connections for increased design action equivalent to 56% of the service load. Full article

In order to study the characteristics of the thermal runaway process of a full-size prefabricated cabin energy storage system, a full-scale prefabricated cabin energy storage physical fire test platform was designed using 100% SOC energy storage battery packs as the thermal runaway object, and full-scale prefabricated cabin energy storage system physical fire experiments were conducted. This experiment analyzes the early change rules of parameters such as temperature, voltage, CO, and VOC after the energy storage system enters thermal runaway and explores the technical methods to improve the fire protection of electrochemical energy storage systems. The results show that the time when the surface temperature of the runaway cell undergoes a sudden change is 37 s later than the time when the voltage undergoes a sudden change; the CO at the bottom and middle of the runaway cluster reaches the alarm threshold 25 s and 39 s earlier than that at the top of the cluster, respectively, and the peak concentration of CO at the bottom and middle of the cluster is more than three times that at the top of the cluster. The opening of the fan causes the CO concentration on the left side of the thermal runaway cluster to be higher than that of the runaway cluster; before the battery thermal runaway, the VOC concentration at the middle and top of the runaway cluster is generally higher than that at the bottom of the cluster. After thermal runaway occurs, the VOC concentration at the bottom of the thermal runaway cluster exceeds that at other positions of the runaway cluster and the adjacent cluster; the t_VOC at the top, middle, and bottom of the thermal runaway cluster is 2296 s, 1681 s, and 1464 s earlier than the t_CO, respectively, but the initial detection value of VOC fluctuates more than that of CO. Full article