Cfd simulation of fire and ventilation in the stations of underground transportation systems

Download
2005
Kayılı, Serkan
The direct exposure to fire is not the most immediate threat to passengers̕ life in case of fire in an underground transportation system. Most of the casualties in fire are the results of smoke-inhalation. Numerical simulation of fire and smoke propagation provides a useful tool when assessing the consequence and deciding the best evacuation strategy in case of a train fire inside the underground transportation system. In a station fire the emergency ventilation system must be capable of removing the heat, smoke and toxic products of combustion from the evacuation routes to ensure safe egress from the underground transportation system station to a safe location. In recent years Computational Fluid Dynamics has been used as a tool to evaluate the performance of emergency ventilation systems. In this thesis, Computational Fluid Dynamics technique is used to simulate a fire incidence in underground transportation systems station. Several case studies are performed in two different stations in order to determine the safest evacuation scenario in CFDesign 7.0. CFD simulations utilize three dimensional models of the station in order to achieve a more realistic representation of the flow physics within the complex geometry. The steady state and transient analyses are performed within a simulation of a train fire in the subway station. A fire is represented as a source of smoke and energy. In transient analyses, a fast t2 growth curve is used for the heat release rate and smoke release rate. The results of the studies are given as contour plots of temperature, velocity and smoke concentration distributions. One of the case studies is compared with a code well known in the discipline, the Fire Dynamics Simulator, specifically developed for fire simulation. In selection of the preferred direction of evacuation, fundamental principles taken into consideration are stated.

Suggestions

Experimental study of solid propellant combustion instability
Çekiç, Ayça; Ulaş, Abdullah; Department of Mechanical Engineering (2005)
In this study, experimental investigation of solid propellant combustion instability using an end burning T-Burner setup is performed. For this purpose, a T-Burner setup is designed, analyzed, constructed and tested with all its sub components. T-Burner setup constructed is mainly composed of a base part, a control panel and the T-Burner itself. Combustion chamber, pressure stabilization mechanism, pressurization system, measurement instruments and data acquisition systems form the T-Burner. Pressure stabil...
An electronic control unit design for a miniature jet engine
Polat, Cuma; Dölen, Melik; Department of Mechanical Engineering (2010)
Gas turbines are widely used as power sources in many industrial and transportation applications. This kind of engine is the most preferred prime movers in aircrafts, power plants and some marine vehicles. They have different configurations according to their mechanical constructions such as turbo-prop, turbo-shaft, turbojet, etc. These engines have different efficiencies and specifications and some advantages and disadvantages compared to Otto-Cycle engines. In this thesis, a small turbojet engine is inves...
Experimental and computational investigation of the emergency coolant injection effect in a candu inlet header
Turhan, K. Zafer; Yeşin, Ahmet Orhan; Department of Mechanical Engineering (2009)
Inlet headers in the primary heat transport system(PHTS) of CANDU type reactors, are used to collect the coolant coming from the steam generators and distribute them into the reactor core via several feeders. During a postulated loss of coolant accident (LOCA), depressurization and vapor supplement into the core may occur, which results a deterioration in the heat transfer from fuel to the coolant. When a depressurization occurs, “Emergency Coolant Injection(ECI)” system in the PHTS in CANDU reactors, is au...
Analysis of regenerative cooling ın liquid propellant rocket engines
Boysan, Mustafa Emre; Ulaş, Abdullah; Department of Mechanical Engineering (2008)
High combustion temperatures and long operation durations require the use of cooling techniques in liquid propellant rocket engines. For high-pressure and high-thrust rocket engines, regenerative cooling is the most preferred cooling method. In regenerative cooling, a coolant flows through passages formed either by constructing the chamber liner from tubes or by milling channels in a solid liner. Traditionally, approximately square cross sectional channels have been used. However, recent studies have shown ...
Comparison of engine performance and emissions for conventional petroleum diesel fuel and diesel-ethanol blends
Erkal, Gül; Yozgatlıgil, Ahmet; Department of Mechanical Engineering (2010)
Ethanol is an environmental friendly alternative diesel fuel that has received significant attention both as a possible renewable alternative fuel and as an additive to existing petroleum-based fuels. Beyond simply representing an additional fuel supply, ethanol exhibits several advantages when compared to existing petroleum fuel. The objective of this work is to investigate experimentally the effects of using different blends of specified percentages of ethanol on the engine performance and emissions and t...
Citation Formats
S. Kayılı, “Cfd simulation of fire and ventilation in the stations of underground transportation systems,” M.S. - Master of Science, Middle East Technical University, 2005.