Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Effects of the ventilation duct arrangement and duct geometry on ventilation performance in a subway tunnel
Highlights ► The effects of the duct number and duct geometry on duct ventilation in a subway tunnel are investigated numerically. ► The total mass flow of the air pushed out of the tunnel increases with the increase in the duct number. ► The location of a specific duct has a strong impact on the total suction and exhaust mass flows through the duct. ► The exhaust effect through a duct is influenced remarkably by the duct geometry.
Abstract This study has investigated numerically the effects of the ventilation duct number and duct geometry on duct ventilation performance in a subway tunnel. A three-dimensional numerical model using the dynamic layering method for the moving boundary of a train, which was validated against the model tunnel experimental data in a previous study, is adopted to simulate train-induced unsteady tunnel flows. For the tunnel and subway train geometries that are exactly the same as those used in the model tunnel experimental test, but with the ventilation ducts being connected to the tunnel ceiling, the three-dimensional tunnel flows are simulated numerically under five different ventilation duct numbers and two different duct geometries. The numerical results reveal that: (1) for a given total area of openings, the ventilation duct number has little influence on the total mass flow of the air sucked into the tunnel through the ventilation ducts while the total mass flow of the air pushed out of the tunnel through the ducts increases remarkably with the increase in the duct number; (2) with the increase of the distance between a specific ventilation duct and the tunnel inlet the suction mass flow through the duct decreases significantly while the exhaust mass flow through the duct increases greatly, i.e., the location of a specific duct has a strong impact on the total suction and exhaust mass flows through the ventilation duct; (3) as the linkage angle between the tunnel ceiling and the upstream side wall of a duct is changed from 90° to 45°, the size of the re-circulation area inside the duct is much reduced when the train approaches the duct and thus the amount of air pushed out of the duct is greatly increased (i.e. the exhaust effect through the duct is remarkably strengthened).
Effects of the ventilation duct arrangement and duct geometry on ventilation performance in a subway tunnel
Highlights ► The effects of the duct number and duct geometry on duct ventilation in a subway tunnel are investigated numerically. ► The total mass flow of the air pushed out of the tunnel increases with the increase in the duct number. ► The location of a specific duct has a strong impact on the total suction and exhaust mass flows through the duct. ► The exhaust effect through a duct is influenced remarkably by the duct geometry.
Abstract This study has investigated numerically the effects of the ventilation duct number and duct geometry on duct ventilation performance in a subway tunnel. A three-dimensional numerical model using the dynamic layering method for the moving boundary of a train, which was validated against the model tunnel experimental data in a previous study, is adopted to simulate train-induced unsteady tunnel flows. For the tunnel and subway train geometries that are exactly the same as those used in the model tunnel experimental test, but with the ventilation ducts being connected to the tunnel ceiling, the three-dimensional tunnel flows are simulated numerically under five different ventilation duct numbers and two different duct geometries. The numerical results reveal that: (1) for a given total area of openings, the ventilation duct number has little influence on the total mass flow of the air sucked into the tunnel through the ventilation ducts while the total mass flow of the air pushed out of the tunnel through the ducts increases remarkably with the increase in the duct number; (2) with the increase of the distance between a specific ventilation duct and the tunnel inlet the suction mass flow through the duct decreases significantly while the exhaust mass flow through the duct increases greatly, i.e., the location of a specific duct has a strong impact on the total suction and exhaust mass flows through the ventilation duct; (3) as the linkage angle between the tunnel ceiling and the upstream side wall of a duct is changed from 90° to 45°, the size of the re-circulation area inside the duct is much reduced when the train approaches the duct and thus the amount of air pushed out of the duct is greatly increased (i.e. the exhaust effect through the duct is remarkably strengthened).
Effects of the ventilation duct arrangement and duct geometry on ventilation performance in a subway tunnel
Huang, Yuan-dong (Autor:in) / Gong, Xiao-lu (Autor:in) / Peng, Yue-jiao (Autor:in) / Lin, Xiao-yu (Autor:in) / Kim, Chang-Nyung (Autor:in)
Tunnelling and Underground Space Technology ; 26 ; 725-733
02.05.2011
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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