• Fire Science and Engineering
• /
• v.26 no.1
• /
• pp.31-37
• /
• 2012

This study is intended to present a computational thermal model for a residential building. As the Performance Based Design is more popular, fire-intensity and fire-load have turned out to be very important factors for building design and can be predicted through some computational work. To predict and estimate the fire properties of a residential fire, we made some numerical models of combustibles and residential building. In a bid to validate the estimate values, computational analysis results from numerical models were compared with real fire tests. For computational analysis, the Fire Dynamics Simulator (FDS) was used with Large Eddy Simulation (LES) model for turbulence. Consequently, fire-intensity was well predicted and flash-over of rooms were successfully estimated.

• Fire Science and Engineering
• /
• v.21 no.2 s.66
• /
• pp.98-104
• /
• 2007

This study is related with the fire risk assessment for fire area at nuclear power plant by use of FDS (Fire Dynamics Simulator) that is a computational fluid dynamics (CFD) model of fire-driven fluid flow. The major purpose of this research is to analyze the sensitivity of the fire modeling when the heat release rate that is an important input variable is changed as well as when the grid size that is a critical factor of the fire model is modified. The result is presented at the conclusion with some comments for CFD model application.

• Fire Science and Engineering
• /
• v.24 no.2
• /
• pp.114-119
• /
• 2010

The fire at a Busan indoor shooting range on November 14, 2009 was reconstructed by using a computational fluid dynamics model for fire simulations, in order to investigate the cause of the heavy death toll in a short period of time. Spread of the flame and smoke, and temperature distribution obtained by fire simulation were compared with the results of fire investigation based on the CCTV recordings. The flame and smoke flew out violently through the door into the cafeteria from the shooting range, and the cafeteria was filled with smoke just within 3 seconds followed by the onset of fire. This is consistent with the CCTV recordings. It was confirmed, as a result, that people in the cafeteria did not have enough evacuation time. The computed temperature at the door knob reached about $1400^{\circ}C$, near its melting point.

• Journal of the Korean Society for Railway
• /
• v.9 no.6 s.37
• /
• pp.625-629
• /
• 2006

This paper describes the effect of the droplet breakup process on fire suppression using a water-mist system, which is considered as a alternative to sprinkler fire suppression system. In the evolution of the water-mist, the droplet breakup process is an important phenomenon because it may significantly affect the droplet evaporation rate. The Fire Dynamics Simulator (FDS, Ver. 4.0) code, which is widely used for the simulation of fire dynamics, is used for the present simulation, and it is modified to consider the droplet breakup phenomena. The Prediction by the modified code shows good agreement with experimental data for the temperature. The original FDS predicts higher temperature about $30^{\circ}C$ than experimental data. From the results, it is concluded that the droplet breakup phenomena must be considered for more precise simulation of fire suppression process.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.290-293
• /
• 2008

In this study, the Computational Fluid Dynamics (CFD) has been used to analyze the smoke movement and the carbon monoxide concentration distribution, both vertically and longitudinally, in a compartment, based on conservation laws. The Fire Dynamics Simulator (FDS) developed by National Institute of Standards and Technology (NIST) was used for numerical simulations using Reynolds averaged Navier-Stokes equations (RANS) model to solve for time-averaged properties. Results show, as a function of time, a detailed distribution of temperature and carbon monoxide concentration changing against the height above the floor and those changes alongside the distance away from the fire source. Fire-induced smoke and toxic gases like CO are more dangerous in a confined space. The result of study may contribute in designing the smoke evacuation system based on the precise tenable condition.

• Journal of the Korean Society of Safety
• /
• v.19 no.1
• /
• pp.18-22
• /
• 2004

The Fire Dynamics Simulator (FDS) was applied to a center fire in a room, of which dimensions were 1.8m${\times}$1.38m with an opening of 0.45m${\times}$1.2m doorway, to evaluate the numerical method. The time-variation of temperature at a top point of thedoorway centerline and distributions of evaluate the numerical method. The time-variation of temperature at a top point of the doorway centerline and distributions of average temperature along the doorway centerline and corner stack were compared with measurements for three different fire sizes, 7.65, 21.25 and 51.71kW. The results showed FDS predicted a very rapid fire growth compared with the experiment for all the three fire sizes, that is an importand shortcoming of FDS in compartment fire simulations. The average temperature distributions, and heights of hot gas layers and neutral planes in steady state were in reasonable agreement with the measurements.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.585-593
• /
• 2011

Actual fire test under a laboratory and fire simulation by using computer are considered into main methodology in order to estimate and predict fire size of railway train. Even if practical fire size could be obtained from the full-model railway car test such as a large scale cone-calorimeter test, it is not always possible and realistic due to that expensive cost and attendant dangers could in no way be negligible. In this point of view, fire simulation analysis method based on the computational fluid dynamics could be proposed as an alternative and it seems to be also efficient and reasonable. However, simulation results have to be verified and validated in accordance with the proper procedure including comparing analysis with the actual fire test. In this paper, fire load and growth aspect was investigated through the room corner test (ISO 9705) for the mock-up model of the actual railway car. Then, it was compared with the output data derived from the simulation by using Pyrolysis Model of the FDS (Fire Dynamics Simulator, by NIST) for the exact same domain and condition corresponding with pre-performed room-corner test. This preliminary verified and validated fire modeling method could enhance the reliability of output data derived from the fire simulation under the similar domain and condition.

• Computers and Concrete
• /
• v.31 no.5
• /
• pp.371-384
• /
• 2023

Precast roofing systems employing prestressed elements often serve as smart structural solutions for the construction of industrial buildings. The precast concrete elements usually employed are highly engineered, and often consist in thin-walled members, characterised by a complex behaviour in fire. The present study was carried out after a fire event damaged a precast industrial building made with prestressed beam and roof elements, and non-prestressed curved barrel vault elements interposed in between the spaced roof elements. As a consequence of the exposure to the fire, the main elements were found standing, although some locally damaged and distorted, and the local collapse of few curved barrel vault elements was observed in one edge row only. In order to understand and interpret the observed structural performance of the roof system under fire, a full fire safety engineering process was carried out according to the following steps: (a) realistic temperature-time curves acting on the structural elements were simulated through computational fluid dynamics, (b) temperature distribution within the concrete elements was obtained with non-linear thermal analysis in variable regime, (c) strength and deformation of the concrete elements were checked with non-linear thermal-mechanical analysis. The analysis of the results allowed to identify the causes of the local collapses occurred, attributable to the distortion caused by temperature to the elements causing loss of support in early fire stage rather than to the material strength reduction due to the progressive exposure of the elements to fire. Finally, practical hints are provided to avoid such a phenomenon to occur when designing similar structures.

• Fire Science and Engineering
• /
• v.20 no.4 s.64
• /
• pp.13-18
• /
• 2006

The fire protection regulation for the nuclear power plants is based on the qualitative fire hazard assessment and the quantitative fire risk analysis, and the fire risk is managed by the fire protection plan with the appropriate balance among the fire prevention, fire suppression and the minimization of the fire effect. In these days, the zone model or the field model is generally used for the detail evaluation for the fire risk. At this paper, with consideration of the present trend, we evaluate whether the quantitative fire risk analysis and the assessment of fire result for fire areas at nuclear power plants can be possible by use of Fire Dynamics Simulator (FDS) that is the state-of-the-art fire modeling tool. Consequently, it is expected that the quantitative fire risk evaluation propelled by the fire modeling can be available as an applicable tool to improve the core damage frequency as well as the quantitative fire risk analysis.

• Fire Science and Engineering
• /
• v.30 no.2
• /
• pp.92-97
• /
• 2016

The present study has been conducted to estimate the chemical flame height based on fuel consumption in fire field model. The calculation algorithms based on cumulative fraction of HRRPUL and fuel concentration along the z axis were applied to the results predicted by Fire Dynamics Simulator (FDS) version 6.3.2 and the mean chemical flame height was obtained by time averaging of instantaneous flame height with the algorithms. The mean flame height calculated by fuel concentration was quite well matched with that of cumulative value of HRRPUL within 10% over-prediction. This study contribute to a more detailed understanding of fire behavior and quantitative evaluation of flame height in the computational fire model.