Effects of curved sidewall on maximum temperature and longitudinal temperature distribution induced by linear fire source in utility tunnel

Wang, Pufan; Zhu, Guoqing; Pan, Rongliang; Chu, Tingxiang; Wang, Zhan; Liu, Haonan

doi:10.1016/j.csite.2019.100555

Cited by 23 publications

(4 citation statements)

References 19 publications

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“…In addition, curved ceiling forms a different smoke layer cross section, comparing with horizontal ceiling, resulting in the governing equations in horizontal ceiling could not be applied into semicircular tunnel directly [3]. Even though several works have been conducted to analysis the jet temperature characteristics under curved ceiling [4][5][6], proposed empirical models were established through dimensionless analysis from experimental data, lacking of government equations employment [4,5]. The other semi-empirical models were proposed based on the governing equations, but evolution of smoke layer cross section and heat transfer were simplified in the governing equations [6].…”

Section: Ltmentioning

confidence: 99%

Two-Dimensional Analysis on Ceiling Jet Temperature Characteristics in a Semicircular Tunnel

et al. 2021

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In order to reveal the evolution of ceiling jet temperature characteristics beneath curved ceiling in two-dimensional view, experimental and theoretical studies were conducted to analyze the vertical temperature profile and longitudinal temperature attenuation beneath a curved ceiling of a semicircular tunnel. The temperature profile was first measured from experiments carried out in the model-scale semicircular tunnel. The relationship between temperature and the horizontal positions is described by an empirical model. A formula describing the thickness of the thermal boundary layer is proposed, based on the vertical distribution of smoke temperature. An engineering model for the longitudinal attenuation of the gas temperature with different fire plume types at impingement region is established in terms of conservation equations. After validation, model predictions show a good agreement with trend proposed by former literature and the relative error of prediction is found to be within 10%. Two-dimensional prediction for temperature profile beneath semicircle ceiling centerline was proposed. It was noted that two-dimensional prediction model could predict majority of measured data within 20% relative error even though some fluctuation, which could be applied to the fire protection engineering in semicircular tunnel.

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Section: Ltmentioning

confidence: 99%

Two-Dimensional Analysis on Ceiling Jet Temperature Characteristics in a Semicircular Tunnel

et al. 2021

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“…Temperature distribution plays an important role in flammability of combustibles and flame spread [10,14,34]. In this work, an infrared camera placed in front of the cables rather than at the top of the cables are employed to capture the temperature distribution of cable surface and flame.…”

Section: Temperature Distributionmentioning

confidence: 99%

Experimental Study on Flammability and Flame Spread Characteristics of Polyvinyl Chloride (PVC) Cable

Tang

Liang

et al. 2020

Polymers

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Polyvinyl chloride (PVC) is widely applied in cables as insulation materials, which are vital for operation and control of industrial processes. However, PVC cables fires frequently occur, arousing public concern. Therefore, experimental methods are used to study flammability and flame-spread characteristics of PVC cable in this paper. Influences of cable structure and number are investigated, which is scanty in previous works. As cable core number of single cable or cable number of multiple cables rises, average flame height and width increase while the increment decreases. Formulas concerning dimensionless flame height and single cable diameter (or total width of multiple cables) are obtained. The former is negatively correlated with the latter. For single cable, convective heat transfer is dominant, and flame-spread rate decreases as cable core number increases. Cable maximum temperature, which drops first and then rises as cable core number increases, is observed in the cable core area. For multiple cable, the flame-spread rate increases as cable number increases. As the cable number rises, the length of pyrolysis and combustion zone increases while the maximum temperature of cable surface decreases. This work is beneficial to fire hazard evaluation and safety design of PVC cables.

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“…Some researchers have also studied fires in moving subway trains, but the fire scenarios mainly focus on straight tunnels. Some studies have reported that the lateral locations of fire source from the tunnel wall affect the critical ventilation velocity and longitudinal temperature field, but these studies ignore the influence of the train blocking ratio [ 15 , 16 ]. According to the results of fire research in tunnel, the blocking ratio between the tunnel and train critically impacts smoke diffusion [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Influence of subway train fire locations on the characteristics of smoke movement in a curved tunnel

Zhou

et al. 2023

PLoS ONE

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Scenario models of a moving subway train can help investigate the influence of different fire locations on smoke propagation characteristics in curved tunnels. To this end, this study adopts the three-dimensional Unsteady Reynolds Average Navier-Stokes equations method and the renormalization group k-ε two-equation turbulence model with buoyancy correction for numerical analysis. The motion of the train is replicated using the slip grid technique. The results indicate that when a fire breaks out on a moving train in tunnels, the piston wind leads the longitudinal movement of the smoke. If a fire erupts in the head or middle car of a moving train, the time of smoke backflow is delayed by 30 s or 17 s, respectively, compared to that for the tail car. The obtained results provide a theoretical basis for reasonably controlling the smoke flow in subway tunnels and reducing casualties in fire accidents.

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Effects of curved sidewall on maximum temperature and longitudinal temperature distribution induced by linear fire source in utility tunnel

Cited by 23 publications

References 19 publications

Two-Dimensional Analysis on Ceiling Jet Temperature Characteristics in a Semicircular Tunnel

Two-Dimensional Analysis on Ceiling Jet Temperature Characteristics in a Semicircular Tunnel

Experimental Study on Flammability and Flame Spread Characteristics of Polyvinyl Chloride (PVC) Cable

Influence of subway train fire locations on the characteristics of smoke movement in a curved tunnel

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