• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.389-396
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• 2018

This paper presents a numerical investigation on the structural response of a multi-story building subjected to spreading multi-compartment fires. A recently proposed simple fire model has been used to simulate two spreading multi-compartment fire scenarios in a 10-story steel-framed office building. By assuming simple temperature rising and distribution profiles in the fire exposed structural components (steel beams, steel column and concrete slabs), finite element simulations using a three-dimensional structural model has been carried out to study the failure behavior of the whole structure in two multi-compartment fire conditions and also in a standard fire condition. The structure survived the standard fire but failed in the multi-compartment fire. Whilst more accurate fire models and heat transfer models are needed to better predict the behaviors of structures in realistic fires, the current study based on very simple models has demonstrated the importance and necessity of considering spreadingmulti-compartment fires in fire resistance design of multi-story buildings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.349-356
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• 2020

The heat release rate (HRR) and fire growth rate of fire for the solid combustibles consisting of multi-materials was measured through the ISO 9705 room corner test, and the computational analysis in a closed compartment was performed to simulate a fire using the heat release rate prediction model provided by a Fire Dynamics Simulator (FDS). The method of predicting the heat release rate provided by the FDS was divided into a simple model and a pyrolysis model. Each model was applied and computational analysis was performed under the same conditions. As the solid combustible consisting of multi-materials, a cinema chair composed mostly of PU foam, PP, and steel was selected. The simple model was over-predicted compared to the predicted heat release rate and fire growth rate using the pyrolysis model in a closed compartment.

• Fire Science and Engineering
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• v.6 no.1
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• pp.17-22
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• 1992

We have derived the general transfer equation for governing the continuity, energy transfer, mass and momentum transfer, and turbulent energy dissipation rate within the fire compartment which has the 800t fire source at the center of the floor. The governing transfer equations have been descretized using the finite volume approach and numerically experimented under the SIMPLE algorithm. In order for the SIMPLE algorithm approach to be physically reliable, the test results are compared with those of Morita's SOR Method using Conjugate Residual Method and found to be close to physical values though the computational convergence time still remains to be upgraded. The treatment of source terms in the system of finite difference equations has been critical in order to converge the governing equations within the appropriate time steps. The criteria of convergence allowance for the whole domain have been checked and the sudden change of the non-linear effects from the source term have been avoided. The criteria has been allowed to be for 5$\times$10$^{-5}$ .

• Fire Science and Engineering
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• v.21 no.4
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• pp.18-24
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• 2007

The purpose of this study is focussed on the numerical predictions of temperature distribution by radiation heat transfer in atrium fire using the field fire model and the CCRHT-3D code. This code uses standard $k-{\varepsilon}$ turbulent model with SIMPLE algorithm and weighted sum of gray gases model regrouping(WSGGM-RG). The WSGGM-RG calculates radiative properties on the reduced computational loads while reserving the accuracy. The numerical results show that lower temperature distributions on the wall and the top ceiling wall can be obtained by considering radiative heat transfer. The temperature on the top ceiling wall can be an important parameter in predicting the operating condition of the sprinkler head.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.6
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• pp.616-622
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• 2000

This paper concerns the application of smoke and fire spread to road tunnel fire problems. When a road tunnel is on fire. a fire protection system of road tunnel have to offer an adequate escape space to human. Therefore, this study carried out a simulation for predicting a spreading path of smoke and fire. The evolution of the flow field is simulated with the low Reynolds number k-$\varepsilon$ turbulent model and SIMPLE algorithm based on the finite volume method.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.398-403
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• 2009

The theoretical bases on characteristics of heat release rate in compartment of building for scenario of smoke management are introduced and the numerical applications to simple compartment model are carried out. The growth stage which is important for smoke management design is modelled as t-squared fire curve including fire growth coefficient with related to growth rate. The conditions for the happening of flashover is presented such as $600^{\circ}C$ of temperature or $20kW/m^2$ of radiation heat flux. After the flashover happen, the fire in compartment changes to fully developed fire having the characteristics of ventilation-controlled fire. As the result of numerical analysis to simple compartment model, the time to reach 900K under ceiling for condition of medium growth is twice for condition of fast growth.

• Fire Science and Engineering
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• v.34 no.4
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• pp.22-28
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• 2020

The heat release rate (HRR) of fire for solid combustibles, consisting of multi-materials, was measured using the ISO 9705 room corner test, and a computational analysis was conducted to simulate the fire using an HRR prediction model that was provided by a fire dynamics simulator (FDS). As the solid combustible consisted of multi-materials, a cinema chair composed primarily of PU foam, PP, and steel was employed. The method for predicting the HRR provided by the FDS can be categorized into a simple model and a pyrolysis model. Because each model was applied and computational analysis was conducted under the same conditions, the HRR and fire growth rate predicted by the pyrolysis model had good agreement with the results obtained using the ISO 9705 room corner test.

• Fire Science and Engineering
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• v.19 no.4 s.60
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• pp.18-25
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• 2005

In this study, numerical analysis of two-dimensional unsteady natural convection of air in a square enclosure heated from below, was performed as a basic research of fire science. SIMPLE algorithm was used to the pressure term of momentum equations in the numerical analysis. The numerical analysis were studied for the two model cases and two heat conditions, respectively, which are different with insulation of enclosures and position of heat applied. Also, the ceiling temperatures of enclosure were measured to compare the accuracy of numerical analysis, and it is found that the temperature predicted by numerical analysis were agreed well with the measurements. Streamline and isotherm of the each model case were acquired for each time step.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.982-988
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• 2007

The input data for the interior material of the train is one of the key points for enhancing the accuracy of fire simulation. In this study, we investigated the Fire Test Methods for the Fire Dynamic Simulator modeling for railroad passenger trains. We should get the thermal inputs such as ignition temperature, conductivity, specific heat, vaporization heat, effective heat release. With the simple conduction model for cone-calorimeter test, they could get more than HRR. Kinds of methodology were introduced for better thermal data for real material.

• Nuclear Engineering and Technology
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• v.43 no.3
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• pp.271-278
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• 2011

When performing fire PSA in a nuclear power plant, an event mapping method, using an internal event PSA model, is widely used to reduce the resources used by fire PSA model development. Feasible initiating events and component failure events due to fire are identified to transform the fault tree (FT) for an internal event PSA into one for a fire PSA using the event mapping method. A surrogate event or damage term method is used to condition the FT of the internal PSA. The surrogate event or the damage term plays the role of flagging whether the system/component in a fire compartment is damaged or not, depending on the fire being initiated from a specified compartment. These methods usually require explicit states of all compartments to be modeled in a fire area. Fire event scenarios, when using explicit identification, such as surrogate or damage terms, have two problems: (1) there is no consideration of multiple fire propagation beyond a single propagation to an adjacent compartment, and (2) there is no consideration of simultaneous fire propagations in which an initiating fire event is propagated to multiple paths simultaneously. The present paper suggests a fire propagation equation to identify all possible fire event scenarios for an explicitly treated fire event scenario in the fire PSA. Also, a method for separating fire events was developed to make all fire events a set of mutually exclusive events, which can facilitate arithmetic summation in fire risk quantification. A simple example is given to confirm the applicability of the present method for a $2{\times}3$ rectangular fire area. Also, a feasible asymptotic approach is discussed to reduce the computational burden for fire risk quantification.