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A comprehensive study on the critical ventilation velocity in tunnels with different geometries
, Article International Journal of Ventilation ; Volume 14, Issue 3 , Mar , 2015 , Pages 303-320 ; 14733315 (ISSN) ; Afshin, H ; Farhanieh, B ; Sharif University of Technology
VEETECH Ltd
2015
Abstract
Longitudinal ventilation is a common technique for smoke management during a fire accident within tunnels. In this paper, fire and smoke movement behaviour in longitudinally ventilated tunnels is investigated focusing on critical ventilation velocity. Firstly, critical velocity (VC) is evaluated for different heat release rates and results are compared and verified with model scale experimental data. Secondly, two fire scenarios inside tunnels with different cross sections are arranged and the reliability of some existing correlations for VC is explored. Results illustrate that using a combined geometric scale rather than the traditional single length-scale ones results in better estimation...
Investigate of Effective Parameters on Critical Ventilation Velocity in Tunnels
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Suitable design of ventilation systems is one of the strategies to deal with phenomenon like fire in tunnels. For design a ventilation system first should recognize fire and effective parameters on it. So we need a good modeling of fire. Whereas the aim of this research is investigate the critical ventilation velocity, we only studying the effects of fire. Two effective parameter of fire is the rate of heat release and rate of smoke release, therefore with studying physics and nature of fire, obtain these parameters. After calculation of fire effects, we should investigate the effective parameters on critical ventilation velocity. The critical velocity is the air flow that helps prevent...
Numerical Study of Various Parameters Affecting Ventilation and Fire- Induced Smoke Movement in Curved Road Tunnels
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
When a fire breaks out in a tunnel, due to the enclosure of the interior of the road tunnels, hot and poison smoke quickly spreads in the tunnel. This phenomenon, in addition to destroy the tunnel structure, causes a lot of financial and human losses. In recent years, research into fire control has become more important with the occurrence of numerous accidents in road tunnels and fatalities. Longitudinal ventilation is still the main method for controlling smoke distribution in tunnels due to lower construction costs and acceptable efficiency. Numerous studies have been conducted to investigate the effect of different and effective parameters on fire control and smoke emissions in direct...