Article
Engineering, Environmental
Yangpeng Liu, Jiaxing Shen, Jing Ma, Guochun Li, Zihao Zhao, Xiaomin Ni, Xishi Wang
Summary: By quickly controlling fire incidents caused by leaks from natural gas pipelines using clean and efficient approaches like water mist, the distribution of OH radicals in fire suppression was visualized through laser-induced fluorescence. The study provided key parameters for water mist system optimization and fire extinguishing process.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Thermodynamics
Yuxin Zhou, Zhirong Wang, Haipeng Gao, Xin Wan, Haoyue Qiu, Jiaxing Zhang, Junyi Di
Summary: The study found that water mist containing additives can significantly improve the inhibitory effect on thermal runaway-induced jet fires in lithium-ion batteries, and can be used as a new type of extinguishing agent.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Chemistry, Physical
Yupeng Yuan, Sifan Wu, Boyang Shen
Summary: The study evaluated the reliability of fine water mist for suppressing fires on hydrogen fuel cell ships using Fire Dynamics Simulator software. It found that fine water mist is not effective in extinguishing hydrogen jet fires, but can effectively reduce fire field temperature and prevent fire spread with appropriate parameters. Increases in droplet size degraded suppression effect, while higher spray velocity enhanced it to a certain extent. Ambient wind speed was identified as an important factor influencing the suppression effect of fine water mist on hydrogen jet fires.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Aerospace
S. Vaisakh, T. M. Muruganandam
Summary: An experimental study was conducted to understand the near flowfield of an over-expanded supersonic wall-jet. The study focused on capturing flow features using shadowgraphy, oil flow visualization, and infrared thermography, with a comparative analysis between the two methods. The research also looked at the ability of these methods to capture supersonic surface flow features and listed their merits and demerits.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
R. Sebastian, A-M Schreyer
Summary: This study investigates the influence of jet spacing on the control effectiveness of air-jet vortex generators in supersonic flow. Using large-eddy simulations and experimental visualizations, the study analyzes the effects of different jet spacings on flow structures, vortical structures, and boundary-layer statistics. The insights gained from this study are crucial for the development of efficient control setups.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Civil
X. L. Zhu, G. Chen, Z. G. Wang, L. S. Wu, J. F. Luo, X. S. Wang
Summary: This paper presents a long projection water mist technique based on axial flow inducing, which can effectively extinguish large oil-immersed power transformer fires at far distances. The experimental results confirm its capability.
FIRE SAFETY JOURNAL
(2022)
Article
Engineering, Multidisciplinary
Mingli He, Guang Zhang, Shaohua Hu, Cheng Wang
Summary: A novel co-flow jet water mist system was proposed to improve the momentum of water mist for efficient fire extinguishing. The introduction of droplets increased the potential core length of the co-flow jet, but also reduced turbulence intensity and axial velocity. This technique has the potential to enhance the performance of water mist systems.
Article
Engineering, Petroleum
Yiqun Zhang, Xiaoya Wu, Shuai Zhao, Chengyu Hui, Gensheng Li, Jingbin Li, Jingsheng Lu, Bo Zhang
Summary: A new SSIJ nozzle is designed to improve the efficiency of waterjet erosion on GHBS. Experimental results show that SSIJ can significantly enhance the erosion volume and efficiency, with the 3D velocity and inserted impeller playing a key role in the improved efficiency.
Article
Engineering, Multidisciplinary
Hong-Zeng Yu
Summary: The study investigated the efficacy and requirements of using water mist to extinguish fires in circular, horizontally-oriented ducts under no fire conditions with air flow provided by a blower. Tests showed that the fire could be successfully extinguished regardless of fire size when the water mist concentration exceeded 300 g/m³ in the air flow. The cooling effect of the tested protection was deemed adequate to maintain the structure integrity of exhaust ducts made of various materials during the fire extinguishment process.
Article
Engineering, Chemical
Tao Liu, Xiao-Yu Yin, Ye-Cheng Liu, Yan Tang, An-Chi Huang, Xi-Lin Dong, Yuan-Jun Liu
Summary: This paper investigated the suppression influence of water mist on oil pool fires, focusing on diesel fires and n-heptane fires as experimental objects. The effects of spray pressure and temperature on water mist suppression were examined, and the fire prevention performance and fire extinguishing mechanisms were analyzed. Factors affecting the fire extinguishing effect of water mist on oil pool fire were discussed.
Article
Engineering, Civil
Yang Liu, Zhixi Fu, Guanghui Zheng, Peng Chen
Summary: Quantitative study on the fire-extinguishing conditions of water mist was conducted through a series of combustion experiments, revealing the main characteristics of an oil pool fire under the action of water mist and establishing a fire extinguishing model. The cooling action of water mist is found to be the primary mechanism for putting out the pool fire.
FIRE SAFETY JOURNAL
(2022)
Article
Thermodynamics
Yuqi Huang, Mengheng Wang, Kangbo Yang, Cangsu Xu, Ke Wu
Summary: Acoustic waves can enhance the fire extinguishing efficiency of water mist by delivering water droplets to the flame. This study investigates the enhancement mechanisms of acoustic waves in extinguishing ethanol fueled flames and finds that the frequency of sound and the induced air speed have significant effects on flame behaviors.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Mechanics
Petronio A. S. Nogueira, Daniel M. Edgington-Mitchell
Summary: The study focuses on the resonance and coupling of an underexpanded circular twin-jet system operating at a specific nozzle pressure ratio. By revisiting particle image velocimetry data, performing proper orthogonal decomposition, and conducting linear stability analysis, the characteristics of the coupling phenomenon are revealed and a hypothesis to explain the experimental observations is proposed.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Environmental
Chan Seok Jeong, Chi Young Lee
Summary: The study indicates that the twin-fluid nozzle outperforms the single-fluid nozzle in fire extinguishing performance, being able to extinguish fires faster and more effectively, while using less water. Additionally, the airflow of the twin-fluid nozzle is identified as a critical factor affecting its fire suppression capabilities.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Mechanics
Qing Wang, Feng Qu, Di Sun, Junqiang Bai
Summary: In this study, the supersonic jet over a convex wall is examined using numerical simulation. The investigation focuses on instabilities, turbulent statistics, and the influence of compressibility effects. The results show that streamwise vortices play a significant role in shear layer instabilities, and compressibility effects inhibit their formation.
JOURNAL OF FLUID MECHANICS
(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)