| 1. |
- Liu, Minzhang, et al.
(author)
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Numerical study on aerodynamic pressure caused by high-speed train passing through the subway station
- 2024
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In: The International Journal of Ventilation. - : Taylor & Francis. - 1473-3315 .- 2044-4044.
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Journal article (peer-reviewed)abstract
- As the demand for efficient travel increased, the train speed is greatly increased and the subway gradually appeared the express train and the slow train. Express trains pass through some stations without stopping. In this case, the pressure transient phenomenon in the tunnel will become severe. In this study, the dynamic mesh simulation is used to study the pressure variations of the tunnel, platform screen door (PSD), and airshaft caused by the piston wind which is generated by the high-speed train passing through the tunnel and station. The effects of train speed, modes of the train passing through the station, number of airshafts and station types on the aerodynamic pressure are analyzed. The results demonstrate that the increase in train speed brings new challenges to the loading capacity of tunnel structure. Airshafts are set at the entrance and exit of the station, which is conducive to the pressure relief of each part of the tunnel structure. Furthermore, a new type of station with two tracks (express line and slow line) is conducted. The peak pressure of PSD is reduced by 48% compared with the conventional station. This study will contribute to the improvement of subway construction and provide theoretical and data support for the operation of the high-speed train.
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| 2. |
- Liu, Weiyue, et al.
(author)
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Study on moving fire smoke characteristics and mechanical ventilation system of tunnel
- 2023
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In: Fire safety journal. - : Elsevier. - 0379-7112 .- 1873-7226. ; 141
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Journal article (peer-reviewed)abstract
- Limited by the narrow space of the tunnel, fire has become one of the important factors threatening the safe operation of subway especially the fire on a moving vehicle. Researches on moving fire through the large length-width ratio of tunnels are extremely lacking at present. This study investigates the characteristics of moving fire and the influence of mechanical ventilation under different conditions. First, a three-dimensional model of the tunnel with the moving train is established, and the dynamic mesh simulation is conducted and validated by the experiments. Then, the variation of smoke temperature distribution under different fire source intensities, train speeds, and blocking ratios are studied. Based on the smoke flow characteristics, the mechanical ventilation with different layouts of draught fans is investigated. It is found that the maximum growth rate of smoke spread is 70.90% with an increase of two fans. Finally, the influence of the tunnel shaft on the smoke characteristics under different fire source locations is discussed. When the fire source is under the shaft, the smoke discharge efficiency reaches the highest, almost 5.89% and 21.91% higher than other conditions. This study provides the basis and reference for the research and control of the tunnel moving fire.
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