Numerical study of smoke propagation in a simulated fire in a wagon within a subway tunnel

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Date

2008-08-10

Authors

Vittori, Felipe
Rojas-Solorzano, L.
Blanco, Armando J.
Urbina, Rafael

Journal Title

Journal ISSN

Volume Title

Publisher

Proceedings of FEDSM2008 2008 ASME Fluids Engineering Conference August 10-14, 2008 Jacksonville, Florida USA

Abstract

This work deals with the numerical (CFD) analysis of the smoke propagation during fires within closed environments. It is evaluated the capacity of the emergency ventilation system in controlling the smoke propagation and minimizing the deadly impact of an eventual fire in a wagon within the Metro de Caracas subway tunnel on the passengers safety. For the study, it was chosen the tunnel section between Teatros and Nuevo Circo subway stations, which consists of two parallel independent twin tunnels, connected through a transverse passage. The tunnels are provided by a longitudinal ventilation system, integrated by a set of reversible fans located at both ends of the tunnels. Three stages were considered in the study: (a) Model set up; (b) Mesh sensitivity analysis; (c) Validation of the physical-numerical parameters to be used in the numerical model; and (d) Simulation of fire scenarios in Metro de Caracas subway stations. Stages (b)-(c), aimed to testing and calibrating the CFD tool (ANSYS-CFX10TM), focused on reproducing experimental data from Vauquelin and Mégret [1], who studied the smoke propagation in a fire within a 1:20 scale road tunnel. Stage (d) critical scenarios were established via a preliminary discussion with safety experts from Metro de Caracas, in order to reduce the computer memory and the number of simulations to be performed. The analyses assessed the reliability of escape routes and alternative paths for the evacuation of passengers. Additionally, the smoke front movement was particularly computed, as a function of time, in order to determine the possible presence of the ¨backlayering¨ phenomenon [5]. Results demonstrate the strengths and weaknesses of the current ventilation system in the event of a fire in the subway tunnel, and suggest new strategies to address this potentially lethal event to minimize the risks for passengers

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Keywords

Research Subject Categories::TECHNOLOGY::Engineering mechanics, mechanical engineering, CFD

Citation

Felipe Vittori, Luis Rojas-Solórzano, Armando J. Blanco, Rafael Urbina; 2008; Numerical study of smoke propagation in a simulated fire in a wagon within a subway tunnel, http://nur.nu.edu.kz/handle/123456789/861