Article
Chemistry, Physical
Yuntao Li, Zhuolun Kuang, Ziyu Fan, Jian Shuai
Summary: The desire for sustainable development has increased the use of hydrogen energy worldwide. Introducing hydrogen into existing natural gas pipelines is a cost-effective option for sustainable development. This study proposes a modified solid flame model to calculate the thermal radiation intensity of a hydrogen-blended natural gas jet fire, taking into consideration the failure consequences of hydrogen blending in pipelines. The modified model is found to be more accurate in predicting the thermal radiation intensity, and its application reveals the variations in safe separation distance with different hydrogen blending ratios, internal pressures, and pipe diameters.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Ecology
Michael J. Campbell, Philip E. Dennison, Matthew P. Thompson, Bret W. Butler
Summary: Safety zones (SZs) are crucial for wildland firefighters to protect themselves from injury or death. An online tool called Safe Separation Distance Evaluator (SSDE) has been introduced to map the safe separation distance (SSD) based on various factors. However, there is a need for ground validation of SZ polygons evaluated using SSDE due to inherent data uncertainty.
Review
Polymer Science
Yukyung Kim, Sanghyuck Lee, Hyeonseok Yoon
Summary: Polymers are currently competing with metals and ceramics for various material characteristics, but their organic composition makes them vulnerable to fire hazards. Developing fire-resistant or flame-retardant polymers is crucial, and introducing flame retardants and utilizing nanofillers are key strategies to enhance their fire performance.
Article
Thermodynamics
Xiaoyu Ju, Xingyu Ren, Evan Sluder, Lizhong Yang, Michael J. Gollner
Summary: Experiments were conducted to quantify the downstream heating effect of inclined fires, and a correlation model was established to predict the downstream heating of 2-D inclined flames in different terrains.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Kuibin Zhou
Summary: This paper investigates the effect of flow separation on the linear flame behavior in the presence of crosswind. The study includes experimental and numerical simulations, considering various factors such as burner rim distance, wind speed, and heat release rate. The results reveal the occurrence of a reverse flame along the upstream direction, caused by the interaction between flow separation and burning flame. The study also analyzes the impact of flow separation on flame geometry and presents a critical criterion for the appearance and disappearance of the reverse flame.
COMBUSTION AND FLAME
(2023)
Article
Remote Sensing
Ying Hong Pheh, Shane Kyi Hla Win, Shaohui Foong
Summary: While conventional small unmanned aircraft systems pose safety risks in indoor environments, the novel spherical indoor Coanda effect drone with closed impellers reduces these risks and allows for safe human-drone interactions.
Article
Thermodynamics
Xingyu Ren, Xiaoyu Ju, Michael J. Gollner
Summary: This study explores the impact of turbulence-induced instabilities on three-dimensional boundary-layer flames, showing that turbulence can trigger the formation of flame streaks, increase the spacing between streaks, and promote the transition of flames to a turbulent state. These findings offer new insights into the structure and heating dynamics of boundary-layer flames.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Meiyu Shi, Xudong Song, Weiguang Su, Juntao Wei, Peng Lv, Jianrong Yang, Guangsuo Yu
Summary: The stability of CH4/O2 inverse diffusion impinging flame is studied using OH* chemiluminescence diagnosis in this study. The effects of different nozzle incidence angles and the impinging distance on the stability of impinging flame and OH* chemiluminescence are investigated. The obtained results show that the flame root of the 45 degrees nozzle breaks and makes noise near the blowout, the lift-off limit has a linear correlation with the impinging distance. It is found that the 90 degrees nozzle has the maximum lift-off limit, the 45 degrees nozzle has the maximum blowout limit. When the impinging distance is more than 20 mm, the lift-off state does not occur for the 60 degrees nozzle. The flame is in the attachment state, the OH* chemiluminescence of the three nozzles enhances as the oxygen flow rate increases. The radial distribution of OH* radicals shows that the peak intensity of the flame decreases with decreasing nozzle incidence angle. The position of the core area of 45 degrees and 60 degrees nozzles increases with the increase of oxygen flow rate. Meanwhile, the position of the reaction core area of the 90 degrees nozzle increases with the oxygen flow rate in the attachment state and decreases monotonically in the lift-off state.
Article
Thermodynamics
Yuhang Chen, Kazui Fukumoto, Xiaolei Zhang, Yujie Lin, Fei Tang, Longhua Hu
Summary: This study experimentally investigates the flame horizontal lengths of elevated and ground pool fires in cross airflows, and compares them. The quantification of this fundamental problem, which considers the air entrainment and combustion structure change due to the ground's Coanda effect at the leeward side, is of practical significance.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Review
Thermodynamics
Yue Zhang, Jun Fang, Hassan Raza Shah, Lei Song
Summary: This study experimentally investigated the effect of an unheated starting segment on solid burning, and found that the presence of the unheated segment led to the formation of vortices and streak structures in the flame, resulting in a larger convective heat transfer coefficient. With increasing unheated length, the flame standoff distance increased while the convective heat transfer coefficient decreased.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Yuxuan Ma, Yusuke Konno, Qiang Wang, Longhua Hu, Nozomu Hashimoto, Osamu Fujita
Summary: Flames propagating along the sample edges will cause interference with material flammability test results. Utilizing an inert wall with a designed air gap distance can minimize this effect. The flame spread rate at the sample edge can be summarized into three regimes based on the air gap distance. The developed flame spread model based on conventional thermal theory accurately reproduces the experimental results and emphasizes the significance of heat loss in the trend of flame spread rate.
COMBUSTION AND FLAME
(2023)
Article
Engineering, Aerospace
Zhonghao He, Hongbo Wang, Fan Li, Yifu Tian, Minggang Wan, Jiajian Zhu
Summary: The ethylene-fueled flameholding characteristics of a cavity-based scramjet combustor were investigated experimentally and numerically. The study analyzed the effects of cavity geometry and injection distance on flame dynamics.
Article
Chemistry, Physical
Qunxiang Gao, Laijun Wang, Wei Peng, Ping Zhang, Songzhe Chen
Summary: Hydrogen energy is gradually improving its position in energy transition due to its unique advantages. Constructing nuclear hydrogen production systems is crucial for large-scale hydrogen production, and studying hydrogen leakage and diffusion behavior is critical for commercializing hydrogen production systems. This study discusses the influence of factors such as wind speed, leakage direction, leakage diameter, leakage height, and leakage angle on leakage diffusion, and determines the longest distance of hydrogen diffusion under severe working conditions. The research also evaluates the peak overpressure impact generated by hydrogen explosion and predicts the minimum separation distance required to avoid safety risks.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Environmental
Shixiang Liu, Xiaolei Zhang, Xu Fang, Longhua Hu
Summary: This study investigates the combustion behaviors and instability characteristics of dual jet flames under cross wind, utilizing propane fire sources with different nozzle diameters and separation distances. The results show that the rear jet flame has a smaller tilt angle and lower blow-out cross wind velocity compared to the front jet flame, due to the interference from the front jet flame. The combustion of the front jet flame also has a restrictive effect on the rear jet flame.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Thermodynamics
Youbo Huang, Yanfeng Li, Jiaxin Li
Summary: Reduced scale experiments were conducted to investigate the geometry of LPG flames in branched tunnel fires under different airflow velocities. The results show that the flame tilts downward towards multiple entrances under natural ventilation, due to the asymmetry of the tunnel cross-section dimensions. A correlation between the flame tilt angle and heat release rate was established, and the predictions using this correlation agreed well with the experimental data. The flame length increased with the heat release rate and was elongated by airflow. Empirical models for dimensionless flame length were developed for both natural and longitudinal ventilation.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Civil
Tarek Beji, Bouaza Lafdal, Rabah Mehaddi
Summary: The paper presents experimental measurements of transient profiles of burning rates and liquid temperatures in methanol and heptane pool fires. The results suggest significant enhancement in heat transfer due to convective motion within the liquid. Additionally, a two-zone approach for the thermal structure within the liquid has been proposed and will be implemented in a numerical code.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Walter Klein-Hessling
Summary: Fire simulations and analytical validation approaches are becoming increasingly important in the fire safety assessment of nuclear power plants. The COCOSYS code has been improved to better simulate cable fires and has been validated through experiments. It provides a set of input parameters for different ventilation conditions.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Bing Wu, Yu Meng, Yongzheng Yao, Baiwei Lei, Jingxin Wang, Junjie Zhai
Summary: Underground laneway fires have a throttling effect on ventilation systems and the amount of CO produced by combustion is significantly influenced by ventilation conditions.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Ahmad Hassan, Gilbert Accary, Duncan Sutherland, Khalid Moinuddin
Summary: Numerical simulations were conducted to study laboratory-scale junction fires with a shrub fuel bed under different unidirectional wind conditions on various terrain slopes and junction angles. The results showed that the decrease in junction angle enhanced fire spread, and the impact of wind speed on fire behavior depended on the intermediate values of the junction angle. The driving heat transfer mode in junction fires varied based on the presence of wind and slope conditions.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Samuel Vaux, Emeline Georges, Hugues Pretrel
Summary: This study investigates an elevated pool fire scenario in a confined and forced ventilated compartment through both experimental and numerical methods. The objective is to enhance the understanding of the phenomena and evaluate the Computational Fluid Dynamics (CFD) capabilities in this configuration. The comparison between large-scale fire tests and numerical simulations reveals differences in fuel mass loss rate and thermal stratifications between elevated and ground fires. The study also highlights the limitations of the predictive approach commonly used for ground fires when applied to elevated fires.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Mira von der Linde, Meinald T. Thielsch
Summary: This study investigates the motivation, emotions, and value of laypeople in fire incidents and finds that their active involvement provides support. The findings are helpful for emergency managers.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Hong-Zeng Yu, Xiangyang Zhou
Summary: This study conducted fire tests to evaluate the effectiveness of incorporating nitrogen to enhance the fire extinguishing capability of water mist in an obstructed, naturally-ventilated enclosure. The results showed that adding nitrogen did improve the water mist's fire extinguishing capability, although the extent of improvement varied depending on the fire size, obstruction, and ventilation conditions.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Rosaria Ono, Marcos Vargas Valentim, Fulvio Vittorino
Summary: This study presents the analysis of unimpeded walking speed of primary school children in descending movement in stairs, including the differences on walking speeds on the flights and landings and the impact of anthropo-metrical data on their walking speed. The research aimed to provide data for evacuation modelling that is not influenced by factors like crowds or adults controlling the flow. The findings show that anthropometrical characteristics or age do not significantly affect the children's movement in free walking condition, and the reduction factor on flights for children is higher than commonly adopted in simulation models.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Nicolas Correa, Juan Cuevas, Andres Fuentes, Jose Luis Torero, Pedro Reszka
Summary: The use of mass timber framing in high-rise buildings requires accurate structural fire performance calculations. A thermal model incorporating char oxidation is proposed in this study, and its effectiveness is validated by replicating experimental results. However, the model fails to accurately simulate the behavior during the later stages of surface combustion.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Bouaza Lafdal, Rabah Mehaddi, Pascal Boulet, Elmehdi Koutaiba, Tarek Beji
Summary: This paper presents a series of 48 enclosure fire experiments conducted in a 1.40 m cubic compartment. A new oscillatory combustion regime is discovered, characterized by alternations between well-ventilated and under-ventilated conditions. This finding calls for a better understanding and further analysis of the underlying physics.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Shenggang Fan, Xingyang Zheng, Jiacheng Zheng, Meijing Liu, Daoyang Dong
Summary: Based on experimental data and constitutive models, a simplified constitutive model of AISI304 stainless steel at high temperatures was proposed and analyzed in this study. Finite element analysis results showed that the simplified constitutive model produced acceptable results compared to the constitutive model fitted based on experimental data, indicating its feasibility and accuracy in calculating the fire resistance of specimens.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Julian E. Mendez, Martyn S. McLaggan, David Lange
Summary: The study characterised the fire spread dynamics in a simplified ventilated facade by conducting parametric experiments. The results showed a strong relationship between flame height and heat release rate. It was also found that the time for encapsulation failure and subsequent cladding material core ignition decreased as the cavity width was reduced. The study highlights the importance of considering the interaction of the products used in the facade and its geometry for the design of facade assemblies when accounting for the fire performance of the system.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
A. Galgano, C. Di Blasi
Summary: A sensitivity analysis was conducted on a one-dimensional solid-gas model for the ignition of thick poly (methyl methacrylate). The study found that the kinetics of polymer decomposition and monomer combustion play a crucial role in ignition time, and the properties of the polymer and the decomposition atmosphere should be properly considered.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Thomas Gernay
Summary: This paper provides an overview of the application of the Performance-Based Design approach in structural fire design. The value of the approach is demonstrated through case studies, and the process and role of the structural fire engineer are described. Recent research conducted at Johns Hopkins University, including issues such as the coupling between fire and thermal-structural models, characterization of material behavior at elevated temperature, numerical modeling of structures in fire, probabilistic risk assessment, and cost-benefit analyses, is discussed. The paper concludes with a discussion of challenges and future perspectives for performance-based structural fire design.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
Salman Ahmad, Hafiz Usman Ahmed, Asad Ali, Xinyi Yang, Ying Huang, Mingwei Guo, Yihao Ren, Pan Lu
Summary: This study investigates the driving behavior patterns of individuals during historical wildfire events and reveals the influence of driving conditions and wildfires on driving behavior, as well as the differences in driving behavior patterns between rural and urban areas.
FIRE SAFETY JOURNAL
(2024)