• Fire Science and Engineering
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• v.24 no.6
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• pp.28-33
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• 2010

The present study develops a numerical model based on the computational fluid dynamics technique to analyse the thermal flow characteristics of large scale fire calorimeter and examine the characteristics of primary parameters affecting on the uncertainty of heat release rate measurement. ANSYS CFX version 12.1 which is a commercial CFD package is used to solve the governing equations of the thermal flow field and the eddy dissipation combustion model and P-1 radiation model are applied to simulate the fire driven flow. The numerical results shows that the horizontal duct system with $90^{\circ}$ bend duct was shown relatively high deviated asymmetric flow profiles at the sampling location and the deviation of the velocity field was higher than that of the temperature and species quantities. The present study shows that the computational model can be applicable to optimize the design process and operating condition of the large scale fire calorimeter based on the understanding of the detail flow field.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.2
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• pp.141-149
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• 2004

In this study, smoke movement in tunnel fire with natural and longitudinal ventilation systems has been investigated. Reduced-scale experiments were carried out under the Froude scaling using 14.55kW fire source with a wick and experimental data is obtained with 1/18 model tunnel test. Temperature profiles were measured under the ceiling and vertical direction along the center of the tunnel and poisonous gas was measured at emergency exit point. The results show that refuge time for 225m intervals of emergency exit in case of natural ventilation systems is 256 seconds and critical velocity for sufficient back-layer prevention is 2.8m/s for fire strength of 20MW.

• Fire Science and Engineering
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• v.17 no.3
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• pp.55-60
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• 2003

This study established analysis theory for flow characteristics prediction of the spray nozzle and predicted discharge and discharge type of the spray nozzle from numerical analysis. It could know that discharge type of the spray nozzle from prediction data determine to position of nozzle and needle, and flow characteristics prediction of the spray nozzle could know that the characteristics according to shape of nozzle and needle is decided. New model of the spray nozzle that can maximize efficiency of fire suppression from flow characteristics and prediction data of the spray nozzle is presented. The result of this study utilize to data necessary to develop new model of the spray nozzle. Also the result of this study wish to contribute to resource technology security of the spray nozzle, technique ripple effect enlargement of same kind industry and technical development activation of fire protection field etc.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2000.11a
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• pp.153-159
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• 2000

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2004.06a
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• pp.131-137
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• 2004

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2004.06a
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• pp.176-184
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• 2004

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.04a
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• pp.150-156
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• 2003

• Fire Science and Engineering
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• v.24 no.3
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• pp.39-44
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• 2010

The cone calorimeter method which is currently used to measure the heat release rate has a fixed rate of radiation. However, in the real fire, when flame combustible material burns, it releases the identical heat flux. We measured the changes of temperature of a fire using FDS in order to analyze flexible heat flux of combustion characteristics. In this study, the rate of radiation of cone calorimeter was adopted by using FDS. Follow those results, it produce between the rate of radiation in the growth period and decline period have a significant impact on heat release rate of PMMA.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.179-184
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• 2010

성능 위주 피난 설계에 있어서 요구피난시간(RSET)을 위한 Simulex 등 피난 시뮬레이션 툴이 사용하고 있는 근본적인 데이터베이스, 즉, 시설 및 군중 조건에 따른 이동 변수, 최대 비유동률(Maximum Specific Flows) 및 경계폭(Boundary Layer Width)을 살펴보고, 트래픽 방정식(Traffic Equation)을 통한 계산 사례 즉, 피난자의 이동 속도 계산 사례, 최소 피난 시간 계산 사례 및 총 유동 용량(Flow Capacity) 수식과 계산 사례를 살펴본다.

• Fire Science and Engineering
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• v.17 no.4
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• pp.86-91
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• 2003

Since the air stream in the room controlled by HVAC system affects on he expected response of conventional detectors which are designed in accordance with normal characteristics of air stream in the fire incident, unexpected operation time delay may occur in fire. In order to solve this problem and to improve sensitivity so that to initiate fire in its early stages for minimizing damage and protecting people, we studied and developed Air Sampling Smoke Detector. The Air Sampling Smoke Detector is a kind of active-type fire detection system. it draws air continuously from the protected area through an air sampling pipe network to the smoke density analyzer. This study presents smoke density analysing technique and air intake balancing technique through an air sampling pipe network. As a result of evaluating, Air Sampling Smoke Detector was much more sensitive than conventional smoke detectors that passively wait for smoke to reach them and was not affected by ambient airflow in the room by means of balanced air intake through the sampling holes.