• Title/Summary/Keyword: Fire dynamics

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Fire Simulations (화재시뮬레이션)

  • Kim Sang-Moon;Yoon Sang-Youl;Kim Kyung-Chun
    • Journal of the Korean Society of Visualization
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    • v.4 no.1
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    • pp.8-13
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    • 2006
  • Fire simulation has been developed for decades to analyze fire cases and provide a tool to study fundamental fire dynamics and combustion. There are three way of fire simulation which are a full scale simulation, an experimental simulation and a computational simulation. In case of a full scale simulation, because a higher cost, a higher risk, more efforts are needed, a demand for it has been decreased. But recently a demand for an experimental simulation and a computational simulation has been increased. A computational simulation has several advantages; lower cost, short period, many case studies, more visual results, a quantitative result and etc. FDS(Fire Dynamics Simulator) which has been developed in BFRL(Building and Fire Research Laboratory), NIST(National Institute of Standards and Technology) is a popular world wide code for fire simulation. Lack of accurate predictions by the model could lead to erroneous conclusions with regard to fire safety. All results should be evaluated by the informed judgment of the qualified user.

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Numerical Simulation of a Forest Fire Spread (산불 전파의 수치 시뮬레이션)

  • Lee, Myung-Sung;Won, Chan-Shik;Hur, Nahm-Keon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.2
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    • pp.137-143
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    • 2008
  • In the present study, a forest fire spread was simulated with a three-dimensional, fully-transient, physics-based, computer simulation program. Physics-based fire simulation is based on the governing equations of fluid dynamics, combustion and heat transfer. The focus of the present study is to perform parametric study to simulate fire spread through flat and inclined wildland with vegetative fuels like trees or grass. The fire simulation was performed in the range of the wind speeds and degrees of inclination. From the results, the effect of the various parameters of the forest fire on the fire spread behavior was analyzed for the future use of the simulation in the prediction of fire behavior in the complex terrain.

A Fire Computer Simulation of Inner Space with Fire Shutters and Refuge Stairs (방화셔터와 피난계단이 존재하는 실내 환경의 화재 컴퓨터 시뮬레이션)

  • Yoo, Doo-Yul;Yang, Jung-Min
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.11
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    • pp.1617-1624
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    • 2013
  • This paper analyzes the relation between fire shutters and fire spread by conducting fire simulation on inner space with fire shutters. Using Fire Dynamics Simulator (FDS), a commercial fire simulation software, the simulation is done on an ideal inner robby, where fire size and the open/close of fire shutters are varied. Our simulation environment can derive significant fire parameters such as temperature variation of fire room walls and entrances of refuge stairs, variation of carbon dioxide, and soot spread. According to the simulation results, temperature and carbon dioxide distribution in refuge stairs have little dependence on vent open or close, but the part close of fire shutters blocks soot inflow to refuge stairs.

A Numerical Study of Fire Dynamics of The Enclosed Compartment with Window Glass Breaking (밀폐된 구획의 창유리 파단시 화재 특성에 관한 수치적 연구)

  • 전흥균;최영상
    • Fire Science and Engineering
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    • v.12 no.2
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    • pp.29-42
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    • 1998
  • The use of computer supported fire safety engineering calculations has grown significantly in recent years and will be increased rapidly. In this study, in order to examine for fire dynamics of the enclosed compartment with window glass(3mm, 4mm thickness) when the window glass breaks, we conducted numerical computer simulations about foam sofa fire with the zone type computer mode, FASTLite package(version 1.1.2) and the Berkeley algorithm for breaking window glass in a compartment fire, BREAK1 program (version 1.0). The analysis of the results in this paper shows that there are differences of fire dynamics between open-or enclosed-state compartment fire and the enclosed compartment fire with window glass breaking. It is also shown in this study that backdraft phenomenum occurs due to accumulated unburned combustible fuel when the glass of 4mm thickness breaks, and that temperature differences between the inner-and outer-surfaces of 3mm and 4mm thick glasses are appreciable. This study will help fire fighter to establish fire suppression or occupant's refuge strategies and fire safety engineer to enhance simulation techniques about the five dynamics of compartment fire.

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Integrated fire dynamics and thermomechanical modeling framework for steel-concrete composite structures

  • Choi, Joonho;Kim, Heesun;Haj-ali, Rami
    • Steel and Composite Structures
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    • v.10 no.2
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    • pp.129-149
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    • 2010
  • The objective of this study is to formulate a general 3D material-structural analysis framework for the thermomechanical behavior of steel-concrete structures in a fire environment. The proposed analysis framework consists of three sequential modeling parts: fire dynamics simulation, heat transfer analysis, and a thermomechanical stress analysis of the structure. The first modeling part consists of applying the NIST (National Institute of Standards and Technology) Fire Dynamics Simulator (FDS) where coupled CFD (Computational Fluid Dynamics) with thermodynamics are combined to realistically model the fire progression within the steel-concrete structure. The goal is to generate the spatial-temporal (ST) solution variables (temperature, heat flux) on the surfaces of the structure. The FDS-ST solutions are generated in a discrete form. Continuous FDS-ST approximations are then developed to represent the temperature or heat-flux at any given time or point within the structure. An extensive numerical study is carried out to examine the best ST approximation functions that strike a balance between accuracy and simplicity. The second modeling part consists of a finite-element (FE) transient heat analysis of the structure using the continuous FDS-ST surface variables as prescribed thermal boundary conditions. The third modeling part is a thermomechanical FE structural analysis using both nonlinear material and geometry. The temperature history from the second modeling part is used at all nodal points. The ABAQUS (2003) FE code is used with external user subroutines for the second and third simulation parts in order to describe the specific heat temperature nonlinear dependency that drastically affects the transient thermal solution especially for concrete materials. User subroutines are also developed to apply the continuous FDS-ST surface nodal boundary conditions in the transient heat FE analysis. The proposed modeling framework is applied to predict the temperature and deflection of the well-documented third Cardington fire test.

Numerical Study on Propylene Vertical Wall Fires (프로필렌 수직벽 화재의 수치적 연구)

  • Park, Woe-Chul
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.133-137
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    • 2009
  • The Fire Dynamics Simulator (FDS), a computational fluid dynamics model for fire simulation, was applied to propylene vertical wall fires, to confirm its accuracy in simulation of vertical wall fires. The temperature profiles at the center of the burner obtained for mass loss rates per unit area in the range of $7.0{\sim}29.29g/m^2-s$ were compared with those of experiment. Comparisons of the heat flux distributions along the vertical centerline on the wall surface were made with the measurements. It was shown that the computed temperature profiles were in good agreement with the experiment. It was also noted that the peak temperature near the wall was underpredicted, the heat flux was too high compared with the measurements, and hence improvements are required for FDS in simulation of the vertical wall fires.

ASSESSMENT ON NUMERICAL ANALYSIS OF THERMAL FLOW INDUCED BY FIRE (화재시 열유동장의 수치해석에 대한 평가 연구)

  • Kim, J.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.156-160
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    • 2011
  • As building becomes larger, taller and more complex due to industrialization and urbanization, it tends to be vulnerable to fire and establishment of effective measures for fire safety is demanded. Especially the fact that the smoke hinders evacuation and fire-fighting activities as well as becomes the major cause of life casualty emphasizes the importance of smoke control system. To design and operate the smoke control system success folly, it is necessary to analyze and predict precisely the thermoflow induced by fire in building. The unsteady three-dimensional analysis of thermoflow induced by fire with diverse variables such as building structure, fire conditions and smoke control facilities can be effectively carried out with numerical method In this study, using the FDS(Fire Dynamics Simulation) program that spreads widely as the analysis tool for thermoflow of fire, the analysis of thermoflow in partition of building induced by fire and comparison with the experimental results for assessment of numerical analysis are presented.

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Evaluation of the Prediction Performance of Design Fire Curves for Solid Fuel Fire in a Building Space (건물 내 고체연료 화재에 대한 설계화재곡선 예측성능 평가)

  • Baek, Bitna;Oh, Chang Bo
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.47-55
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    • 2019
  • The prediction performance of design fire curves was evaluated using a Fire dynamics simulator (FDS) for a solid fuel fire in a building space by comparing the results with experimental data. EDC 2-step mixing controlled combustion model was used in the FDS simulations and the previously suggested 2-stage design fire (TDF), Quadratic and Exponential design fire curves were used as the FDS inputs. The simulation results showed that smoke propagation in the building space was significantly affected by the design fire curves. The predictions of simulations using design fire curves for the experimental temperatures in the building space were reasonable, but the TDF was found to be the most acceptable for predicting temperature. The predictions with each design fire curve of species concentrations showed insufficient agreement with the experiments. This suggests that the combustion model used in this study was not optimized for the simulation of a solid fuel fire, and additional studies will be needed to examine the combustion model on the FDS prediction of solid fires.

Analysis of Smoke Behavior in Fire within Real-scale Theater Using FDS: Influences of Fire Curtain and Natural Smoke Vent Area (FDS를 이용한 실규모 공연장 무대 내 화재 시 연기 거동 분석: 방화막 및 자연배출구 면적의 영향)

  • Kim, Jae Han;Lee, Chi Young;Jeong, Lee Gyu;Kim, Duncan
    • Fire Science and Engineering
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    • v.32 no.6
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    • pp.7-14
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    • 2018
  • This study investigated numerically the influences of fire curtain and natural smoke vent area on smoke movement in the stage fire of a theater using FDS (Fire Dynamics Simulator). The dimension of the theater stage was 31 m in width, 34 m in depth, and 32 m in height. The area ratios between the natural smoke vent and stage were approximately 10%, 8%, 5%, and 1%. The gap distance between the fire curtain and proscenium wall was 0.5 m. The fire curtain and natural smoke vent area were observed to affect significantly the behavior of smoke movement to the auditorium and the mass flow rates of inflow and outflow through the natural smoke vent and proscenium opening. In addition, under the same natural smoke vent area, the pressure in the stage with a fire curtain was lower than that without a fire curtain.