Article
Thermodynamics
Subrata Bhattacharjee, Thomas Delzeit
Summary: In this study, closed-form expressions for the flame spread rate of opposed-flow flame spread over thermally thin and thick cylindrical fuels were developed using the scaling approach. A criterion for delineating thermally thin and thick cylinders was established based on the equality of the heated layer thickness and the radius. It was found that the spread rate of cylindrical fuels is always higher than that of flat fuels with a half-thickness equal to the radius of the cylindrical sample. For thermally thin cylinders, the predicted spread rate is at least two times faster than the corresponding flat fuel.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Rongwei Bu, Chuangang Fan, Yang Zhou
Summary: This study experimentally investigates the effect of fuel bed width on concurrent flame spread over discrete fuels. The results show that the flame spread rate is lower for dense arrays compared to loose arrays. A predictive model of flame spread rate is developed and agrees well with experimental results. Additionally, the heat flux decay behind the pyrolysis zone is more rapid for dense arrays compared to loose arrays.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Construction & Building Technology
Tao Wang, Yanhua Tang, Zhe Wang, Weiguang An, Xiao Chen
Summary: This study provides a comprehensive understanding of the effects of cable inclination angle and longitudinal wind on the flame spread behaviors of cables in utility tunnels. The results show that both flame length and pyrolysis length increase with sin theta and longitudinal wind speed. The increasing inclination angle and wind speed contribute to the increasing flame spread rates. The establishment of a model based on heat transfer analysis helps in predicting the flame propagation rate under different cable inclination angles.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Energy & Fuels
Rongwei Bu, Yang Zhou, Chuangang Fan, Zhengyang Wang
Summary: The study on flame spread over discrete fuel arrays showed that the average flame spread rate is independent of the fuel bed width for n > 1, and the heat transfer mechanism changes from radiant dominance to convective dominance as the inclination angle increases. The flame length is controlled by factors such as upward buoyancy flow and lateral air entrainment during the upward flame spread process, providing a comprehensive insight into the behavior of flame spread over discrete fuels.
Article
Construction & Building Technology
Yang Zhou, Binyan Xu, Xiaonan Zhang, Fei Chen, Rongwei Bu
Summary: This study experimentally investigated the flame spread characteristics of hollow structure solids. The results showed that the burning inside the sample changed with the increasing inner diameter, and the effect of sample thickness on mass loss rate was less evident. A calculation model and dimensionless relationship were proposed to analyze the flame spread.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Yunji Gao, Xiaolong Yang, Yueyang Luo, Feng Guo, Yuchun Zhang, Liang Gong
Summary: The experiments show that the flame spread rate and length are influenced by the inclination angle. As the angle increases, the self-induced buoyancy effect strengthens, but the flame spread rate and length on the remaining side decrease significantly after one-side extinction.
FIRE AND MATERIALS
(2022)
Article
Engineering, Multidisciplinary
Yunji Gao, Yuchun Zhang, Chunjie Mou, Xiaolong Yang, Liang Gong
Summary: This paper investigated the effects of limited distance on two-sided upward flame spread, revealing unexpected phenomena such as one-sided flame blow off and non-monotonic trends in flame length and spread rate with the increase in limited distance. The qualitative explanation based on Damkohler number and surface temperature profile provides insights into the mechanism of flame blow off and upward flame spread under limited distance conditions.
Article
Thermodynamics
Siyao Jia, Longhua Hu, Yuxuan Ma, Xiaolei Zhang, Osamu Fujita
Summary: This study investigates the downward flame spread and extinction over inclined electrical wire under horizontal wind. The results show a non-monotonic trend of flame spread rate with increasing horizontal wind velocity, identifying four different regimes based on heat transfer mechanisms. The flame spread rate of Cu-core wire and NiCr-core wire exhibit different dependencies on inclination angle, showcasing enhanced quenching effect and weakened blow-off effect with increased inclination angle.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
F. H. Vance, Y. Shoshin, L. P. H. de Goey, J. A. van Oijen
Summary: This study focuses on the mechanisms governing flame stabilization without a vortex, redefines flame anchoring locations, and evaluates the impact of flame holder size on flame speed. New insights into flame blow-off, flashback, and vortex emergence are obtained as a result of this investigation.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Longjuan Ji, Jinhua Wang, Weijie Zhang, Runze Mao, Guangya Hu, Zuohua Huang
Summary: This study experimentally investigated the blow-off and flame macrostructure transition behavior of unconfined and confined premixed CH4/air flames. The results showed that the combustor confinement could significantly broaden the blow-off limits. The influence of confinement ratio (CR) on flame stabilization was revealed by analyzing flame structures and flow fields. The transition from stable to unstable was extended by increasing the CR in the confined combustor.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Chemistry, Physical
A. G. Shmakov, V. V. Kozlov, M. V. Litvinenko, Yu. A. Litvinenko
Summary: The addition of inert gases to hydrogen narrows the velocity range of stable combustion, while the addition of reactive gases affects the critical velocity of flame blow-off. The results depend on the mean molecular weight of the combustible mixture and the inhibiting effect of gases on the chemical reactions of hydrogen oxidation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Girish Sapra, Subhash Chander
Summary: An experimental study investigated the LBO characteristics of a tangential entry dual swirling flame, showing significant influence of outer flame Reynolds number and swirl intensity on flame behavior and reactant mixing. The presence of an inner supporting flame and impingement surface improved LBO limits, while geometric design parameters also played a major role in enhancing stability. The dual flame demonstrated significant improvements in lean blow-off limits compared to a single outer swirling flame.
Article
Thermodynamics
F. H. Vance, Y. Shoshin, L. P. H. de Goey, J. A. van Oijen
Summary: By varying the radius of flame holders and mixture velocity, different mechanisms of flame stabilization can be observed under different conditions. Flame curvature plays a significant role in flame stretch, and the presence of RZ alters the stabilization mechanism of the flame.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Y. Li, A. Guibaud, J. -m. Citerne, J. -l. Consalvi, A. Coimbra, J. Sarazin, S. Bourbigot, J. L. Torero, G. Legros
Summary: The effects of flame retardants on flame extinction, flame spread rate, and smoke emission in microgravity are still not well understood. In this study, thin cylindrical samples of LDPE loaded with different intumescent flame retardants were ignited in parabolic flights to investigate their performance. The results showed that the addition of flame retardants did not significantly affect the flame extinction limit, but increased the range of conditions leading to smoke emission, which is detrimental to fire safety. Therefore, a cautious integration of flame retardants is necessary in the context of space exploration.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Wenlong Wang, Jun Fang, Luyao Zhao, Yue Zhang, Jinjun Wang, Yongming Zhang
Summary: This study investigated upward flame spread over thin charring material under different ambient pressures and oxygen concentrations diluted with inert gases. Unique combustion behaviors were observed, with one branch of flame accelerating in a cycle due to secondary pyrolysis and surface oxidative degradation of remaining char, while the other branch eventually extinguished due to self-induced buoyant blow-off.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Thermodynamics
Shakeel Ahmad, Chung Ki Cheng, Kwun Ting Lau, Shahid Ali Khan, Xinyan Huang, Jiyun Zhao
Summary: This work investigates the rapid boiling heat transfer over an integrated surface with cavities and pillars at nanoscale using molecular dynamics simulations. The results show that the integrated surface has a lower bubble nucleation time, higher evaporation rate, and higher heat flux compared to other surfaces.
HEAT TRANSFER ENGINEERING
(2023)
Article
Thermodynamics
Zilong Wang, Tianhang Zhang, Xinyan Huang
Summary: This work explores real-time prediction of fire heat release rate using fire scene images and deep learning algorithms. A large database of fire tests is formed to train the deep learning model. The results show that the proposed AI-image fire calorimetry method can well identify the transient fire heat release rate using only fire scene images.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Multidisciplinary
Feng Zhu, Xinyan Huang, Xiao Chen, Shuangfeng Wang
Summary: The behaviors of flame in a narrow gap with low-velocity airflow were studied. It was found that the flame spread can transition to fuel regression and extinction as the airflow and oxygen concentration decrease. This research provides new insights into flame behavior under oxygen-limited and microgravity environments.
Editorial Material
Engineering, Multidisciplinary
Xinyan Huang, Yi Wang, Eric Guillaume
Article
Computer Science, Artificial Intelligence
Yishuo Jiang, Ming Li, Wei Wu, Xiqiang Wu, Xiaoning Zhang, Xinyan Huang, Ray Y. Zhong, George G. Q. Huang
Summary: A digital twin is a digital version of an object or activity that reflects its properties and behavior through virtual models and data. It is widely used in the construction, operation, and maintenance of infrastructure and facilities. Stakeholders from different disciplines are involved in the long-term management of IoT and digital twin-enabled smart infrastructures and conflicts can arise due to differences in experience, knowledge, and interests. This paper proposes a Ubiquitous Digital Twin model based on Domain-Driven Design to manage complex infrastructure systems and evaluates it through three instantiated scenarios.
ADVANCED ENGINEERING INFORMATICS
(2023)
Article
Thermodynamics
Shakeel Ahmad, Zulfiqar Ali, Syed Waqar Ali Shah, Xinyan Huang, Jiyun Zhao
Summary: This study used alternating wettability inspired by an electric field to enhance boiling heat transfer performance over a rough surface. The simulation results showed that alternating wettability can accelerate bubble expansion and shrinking, leading to a 53% increase in critical heat flux at high wall superheats.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Chuangang Fan, Dia Luan, Rongwei Bu, Ziqiong Sheng, Feiyue Wang, Xinyan Huang
Summary: Extreme rainfall events due to global warming have been investigated for their impact on tunnel fires and smoke spread. Reduced-scale experiments with varying rainfall intensities, raindrop sizes, and fire heat release rates were conducted. It was found that heavy rainfall induced a longitudinal airflow inside the tunnel, causing the flame to tilt towards the no-rainfall portal. This induced airflow had a limited effect on the burning rate of pool fires, but it affected the ceiling temperature and prevented smoke back-layering towards the rainfall portal. The distribution of ceiling temperature towards the no-rainfall portal was not sensitive to rainfall and could be described by an empirical model.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Environmental
Xinqi Zhang, Jihao Shi, Ming Yang, Xinyan Huang, Asif Sohail Usmani, Guoming Chen, Jianmin Fu, Jiawei Huang, Junjie Li
Summary: This study proposes a leakage detection and localization approach by integrating attention mechanism with LSTM network. A labor-scale pipeline leakage experiment is conducted to construct the benchmark dataset and a comparison between the proposed approach and the state-of-the-art methods is performed. The results demonstrate higher accuracy with AUC = 0.99.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Thermodynamics
Yanhui Liu, Gulzhan Aldan, Xinyan Huang, Menglong Hao
Summary: This work proposes a static flow-based immersion cooling method for a six-cell cylindrical Li-ion battery module, which can limit the temperature below 40 degrees C and exhibit superior cooling capability over air cooling. A three-dimensional numerical model is established to analyze and optimize the cooling system's performance, suggesting a higher cooling rate compared to forced air-cooling. The effects of ambient temperature and liquid volume have also been investigated.
APPLIED THERMAL ENGINEERING
(2023)
Article
Computer Science, Artificial Intelligence
Xinqi Zhang, Jihao Shi, Xinyan Huang, Fu Xiao, Ming Yang, Jiawei Huang, Xiaokang Yin, Asif Sohail Usmani, Guoming Chen
Summary: This study proposes a deep probabilistic graph neural network that models the spatial dependency of sensors to improve leakage detection. The results demonstrate that the model achieves competitive detection accuracy and provides more comprehensive leakage detection information. Additionally, the model's posterior distribution enhances leakage localization accuracy.
EXPERT SYSTEMS WITH APPLICATIONS
(2023)
Article
Engineering, Civil
Wai Kit Cheung, Yanfu Zeng, Shaorun Lin, Xinyan Huang
Summary: This study investigates the transport and hazards of carbon monoxide (CO) from smouldering fire for building performance-based design practices. The results show that the smouldering fire scenarios and their CO hazards should be considered in the design of building fire safety. The simulations also reveal that smouldering fires can be more dangerous with lower atrium height and that ceiling ventilation is effective in extracting CO emissions.
FIRE SAFETY JOURNAL
(2023)
Article
Engineering, Civil
Zilong Wang, Yifei Ding, Tianhang Zhang, Xinyan Huang
Summary: This study proposes a novel computer vision method to automatically measure the real-time fire heat release rate accurately, even when the camera is moving. A portable binocular stereo camera captures the real-time fire video stream, which is then fed into a pre-trained computer-vision model to detect the fire region. The distance between the camera and the fire source is determined by identifying the fire location, enabling the deep learning model to output the transient fire power in real time.
FIRE SAFETY JOURNAL
(2023)
Article
Chemistry, Physical
Ruixiang Bai, Yangbing Wei, Jiyuan Xu, Xiaobo Li, Menglin Li, Ziwen Zou, Xinyan Huang, Chengyu Liu, Yiwei Sun, Menglong Hao
Summary: A new thermal interface material (TIM) is developed by encapsulating vertically aligned carbon nanotubes arrays (VACNTs) with copper microfoils, providing a solution to VACNTs' problem in device integration and contact resistance. The new TIM demonstrates excellent thermal performance and reliability in light emitting diode (LED) cooling experiment.
Article
Thermodynamics
Supan Wang, Chunyin Zhang, Kaifeng Wang, Xinyan Huang
Summary: This study investigates the influence of external airflow on the ignition flash and fire points of building insulation materials. The results show that airflow can facilitate the attainment of flash and fire points, with a stable delay time at higher airflow velocities. Flame retardants can inhibit the transition to fire point but do not affect the flash ignition.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
C. X. He, Y. H. Liu, X. Y. Huang, S. B. Wan, Q. Chen, J. Sun, T. S. Zhao
Summary: A decentralized centroid multi-path RC network model is constructed to improve the temperature prediction accuracy compared to traditional RC models. By incorporating multiple heat flow paths and decentralizing thermal capacity, a more accurate prediction is achieved.
ENERGY CONVERSION AND MANAGEMENT
(2024)