Smoke Movement in a Sloping Subway Tunnel Under Longitudinal Ventilation with Blockage

Zhu, Kai; Shi, Long; Wu, Bing; Zhang, Shaogang; Yang, Hui; Zhang, Ruifang

doi:10.1007/s10694-017-0667-x

Cited by 29 publications

(12 citation statements)

References 23 publications

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“…However, although these differences exist, it is found that the effects of these two blockages on the smoke flow properties in some scenarios are similar. In the studies of Zhu et al 9 (12) and (17). The predictions match well with the simulation results, indicating a good applicability of these correlations.…”

Section: The Comparison Between the Passenger Blockage And The Vehisupporting

confidence: 73%

“…3 Therefore, the control of the smoke flow during a tunnel fire is often an important part of emergency planning. [8][9][10] For tunnels without vehicular blockages, some correlations were developed to predict the smoke back-layering length, critical ventilation velocity, and maximum smoke temperature beneath the ceiling. [8][9][10] For tunnels without vehicular blockages, some correlations were developed to predict the smoke back-layering length, critical ventilation velocity, and maximum smoke temperature beneath the ceiling.…”

Section: Introductionmentioning

confidence: 99%

“…[4][5][6][7] Since the commonly used smoke control method in tunnels is the longitudinal ventilation, understanding the smoke behaviors under various longitudinal ventilation scenarios is of great importance. [8][9][10] For tunnels without vehicular blockages, some correlations were developed to predict the smoke back-layering length, critical ventilation velocity, and maximum smoke temperature beneath the ceiling.…”

Section: Introductionmentioning

confidence: 99%

“…In the studies of Zhu et al9 and Zhang et al, 31 the smoke back-layering lengths were obtained experimentally under the different heat release rates, longitudinal ventilation velocities, and vehicle blockages. It can be seen that the smoke layer height decreases with increasing blockage ratio when other conditions are the same.…”

mentioning

confidence: 99%

“…and Zhang et al,31 the smoke back-layering lengths were obtained experimentally under the different heat release rates, longitudinal ventilation velocities, and vehicle blockages. In the scenarios chosen for comparison from the study of Zhu et al,9 the train length was chosen as the blockage length. Thus, the dimensionless blockage length and ratio introduced into Equation (12) were 4 and 0.57, respectively.…”

mentioning

confidence: 99%

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Effects of passenger blockage on smoke flow properties in longitudinally ventilated tunnel fires

Wang

2019

Fire and Materials

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This paper investigates the effects of passenger blockage on smoke flow properties in longitudinally ventilated tunnel fires. A series of numerical simulations were conducted in a 1/5 small-scale tunnel with the different heat release rates (50-100 kW), longitudinal ventilation velocities (0.5-1 m/s), passenger blockage lengths (2-6 m), and ratios (0.17-0.267). The typical smoke flow properties in different tunnel fire scenarios are analyzed, and the results show that under the same heat release rate and longitudinal ventilation velocity, the smoke back-layering length, maximum smoke temperature, and downstream smoke layer height decrease with increasing passenger blockage length or ratio. The Li correlations can well predict the smoke backlayering length and maximum smoke temperature in tunnel fire scenarios without the passenger blockage. When the passenger blockage exists, the modified local ventilation velocity that takes the blockage length and ratio into account has been proposed to correct the Li correlations. The smoke back-layering length and maximum smoke temperature with the different blockage lengths and ratios can be predicted by the modified correlations, which are shown to well reproduce the simulation results. K E Y W O R D S passenger blockage, smoke flow, tunnel fire

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Section: The Comparison Between the Passenger Blockage And The Vehisupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Effects of passenger blockage on smoke flow properties in longitudinally ventilated tunnel fires

Wang

2019

Fire and Materials

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Effect of metro train on the critical driving force for preventing smoke back‐layering in tunnel fires

et al. 2021

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Summary Preventing smoke back‐layering in longitudinal‐ventilated tunnels is an important topic in handling with fires safety issues. Previous studies focused on the critical velocity, while only very few of them paid attention to how to realize this parameter, that is, in a critical state, to overcome the resistance of the tunnel and the fire source to the airflow, the required driving force provided by the ventilation equipment installed in the tunnel. This study addressed this problem in the situation where the coupling effect of blockage and throttling effect was highlighted by conducting theoretical analysis and numerical simulations. The results showed that the presence of metro train blockage reduces the effective cross‐sectional area of the tunnel near the fire source and decreases the critical velocity. On the other hand, the blockage of trains also increases the resistance to the ventilation airflow and exacerbates the throttling effect, leading to the increase of the critical driving force. In such conditions, a stronger driving force to approach the critical velocity was needed. Besides, the length of train blockage was verified to exert limited influence on the value of critical velocity while it significantly affected the critical driving force. Furthermore, the calculated formula for the critical driving force was proposed with the prevention of smoke back‐layering considering the blockage effect to be emphasized.

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Real-Time Prediction of Smoke Spread Affected by Multiple Factors in Subway Tunnel Using CAERES-DNN Model

Jiang

et al. 2021

Fire Technol

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Smoke Movement in a Sloping Subway Tunnel Under Longitudinal Ventilation with Blockage

Cited by 29 publications

References 23 publications

Effects of passenger blockage on smoke flow properties in longitudinally ventilated tunnel fires

Effects of passenger blockage on smoke flow properties in longitudinally ventilated tunnel fires

Effect of metro train on the critical driving force for preventing smoke back‐layering in tunnel fires

Real-Time Prediction of Smoke Spread Affected by Multiple Factors in Subway Tunnel Using CAERES-DNN Model

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