• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.202-207
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• 2009

In this study, Numerical simulations were performed to analyze the characteristics of fire driven smoke flow for different location of fire source in the deeply underground subway station with using FDS code. The fire driven smoke-flow which was simulated by using Parallel Computational Method for fast calculation and LES for turbulence model. In this research, the fire location to obstruct a suitable egress from the fire disaster were discussed.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.505-507
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• 2010

In this paper, the comparison on the fire driven smoke flow for platform types was conducted in the Deeply Underground Subway Station. Soongsil-University station (47m depth) as a bank type platform and Mandeok Station as a island type platform were selected for fire numerical simulation. The characteristics of fire driven smoke-flows were analyzed from the simulation results. The proper plan of evacuation against fire for each type was considered through the results.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.208-213
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• 2010

In this study CFD(Computational Fluid Dynamics) analysis of the steady fire-driven fuid flow for the performance test of ventilation at railway tunnel between Heuksok and Nodeul Station from Seoul Metro 9 is performed. There were fans with exhaust and intake modes and each was installed at the middle and both ends of the tunnel. For this test, the pool fire source of methyl alcohol with 1.5MW and smoke generators were installed between the middle of tunnel and Heuksok Station. In this test, the smoke behavior from natural convection was observed for 10 minutes from the ignition of pool fire and then fans with intake-modes at both sides of Heuksok effect of fan-on with intake mode located in the opposite side of the tunnel nearby Heuksok Station on fire-driven fluid flow is studied on when the boundary conditions of fan-on at the tunnel between Heuksok and Nodeul Station are the same as test. FLUENT, a commercial CFD code, is used for this analysis.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1054-1061
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• 2009

This research was performed with emphasis on fire driven flow behavior and smoke exhaust efficiency which depend on the presence of PSD which are being installed domestically and overseas. For simulation, Jung-ang-ro station of Dae-gu subway station was chosen as model, and fire driven flow analysis was performed by using FDS as flow analysis code. Since many calculation time are required for calculation due to increase in the number of grid as the entire station is modeled, simulation was conducted in parallel processing technique. The fire driven flow analysis was analyzed case by case with composing fire scenario to compare fire driven flow and smoke exhaust efficiency changes depending on the presence of PSD. For fire scale, fire strength of 10MW was studied by referring to NFPA-l30. The calculation results were analyzed with focus on passenger safety by referring to NFPA-130.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.66-72
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• 2008

In this study, transient 3D numerical simulations were performed to analyze the characteristics of fire driven flow for smoke ventilation system operating conditions in the deeply underground subway station. The smoke flow patterns were compared and discussed under smoke fan operating mode and off mode in the platform. Soongsil Univ. station(line number 7)was chosen for simulation which was the one of the deepest underground subway stations in the each lines of Seoul. The geometry for model is 365m in length include railway, 23.5m for width, 47m for depth. Therefore 10,000,000 structured grids were used for fire simulation. The parallel computational method for fast calculation was employed to compute the heat and mass transfer eqn's with 6 CPUs(Intel 3.0GHz Dual CPU, 12Cores) of the linux clustering machine. The fire driven flow was simulated with using FDS code in which LES method was applied. The Heat release rate was 10MW and The Ultrafast model was applied for the growing model of the fire source.

• Journal of computational fluids engineering
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• v.14 no.3
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• pp.115-122
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• 2009

Numerical methods are applied to simulate the smoke behavior in a ventilated tunnel using large eddy simulation (LES) which is incorporated in FDS (Fire Dynamics Simulator) with proper combustion and radiation model. In this study, present numerical results are compared with data obtained from experiments on pool fires in a ventilated tunnel. The model tunnel is $182m(L){\times}5.4m(W){\times}2.4m(H)$. Two fire scenarios with different ventilation rates are considered with two different fire strengths. The present results are analyzed with those from LES without combustion and radiation model and from RANS ($\kappa-\epsilon$) model as well. Temperature distributions caused by fire in tunnel are compared with each other. It is found that thermal stratification and smoke back-layer can be predicted by FDS and the temperature predictions by FDS show better results than LES without combustion and radiation model. The FDS solver, however, failed to predict correct flow pattern when the high ventilation rate is considered in tunnel because of the defects in the tunnel-inlet turbulence and the near-wall turbulence.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.1984-1989
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• 2008

In this study, fire simulations were performed to analyze the characteristics of the fire driven flow and the effects of the platform screen door on the smoke flow in the station, when the fire occurred in the center of the platform. Soongsil Univ. station (line number 7, 47m in depth underground) was chosen which was the one of the deepest underground subway stations in the Seoul metro, SMRT. The parallel computational method was employed to compute the heat and mass transfer eqn's with 6 CPUs of the linux clustering machine. The fire driven flow was simulated with using FDS code in which LES method was applied. The Heat release rate was 10MW and The Ultrafast model was applied for the growing model of the fire source. The 10,000,000 structured grids were used.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.7
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• pp.976-982
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• 2002

In this study, smoke movement in tunnel fire with natural ventilation shaft has been investigated with various size of fire source. Gasoline pool fire with different size of diameter - 73mm, 100mm, 125mm and 154mm - was used to describe fire source. Experimental data is obtained with 1/20 model tunnel test and its results are compared with numerical results. The computation were carried out using FDS 1.0 which is a field model of fire-driven now. Temperature profiles between measured and predicted data are compared along ceiling and near the ventilation shaft. Both results are in good agreement with each other. In order to evaluating a safe egress time in tunnel fire, horizontal smoke front velocity was measured in model tunnel fire tests and those are compared with numerical results. According to the presence or absence of natural ventilation shaft, ventilation effect are estimated quantitatively. Finally, this paper shows that computational fluid dynamics(CFD) is applicable to predict fire-induced flow in tunnel.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.373-378
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• 2011

As the number of deeply-underground subway station(DUSS) increases, the safety measures for DUSS have been requested. In this research, Shingumho station (The line # 5, Depth: 46m) has been selected as case-study for the analysis of smoke-spread speed with the different fire strength. Field test data measured for actual fan in DUSS was applied as a condition of a simulation. The whole station was covered in this analysis and total of 4 million grids were generated for this simulation. The fire driven flow was analyzed case by case to compare the smoke-spread effect according to the fire strength. in order to enhance the efficiency of calculation, parallel processing by MPI was employed and large eddy simulation method in FDS code was adopted.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.4
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• pp.344-350
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• 2006

The present study investigates the characteristics of fire-driven heat flows and gas concentration in a compartment fire by using the modified VHS model (MVHS). The main idea of this model is to add some source terms for combustion products and oxygen consumption to the original VHS model for providing more accurate and useful information on gas concentration distributions as well as thermal fields. It is found that the present MVHS model shows fairly good agreement with the experimental data and the eddy breakup combustion model. The tilting angle of fire plume calculated by MVHS is larger than that of EBU model because the fire source of VHS is affected by ventilating flow less than EBU. However, this discrepancy is apparently reduced in the downstream region of fire source.