• Title/Summary/Keyword: 연기유동

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The dynamic characteristics of upper hot gas layer and smoke propagation along with tunnel slope in case of fire (터널 내 화재 시 경사에 따른 온도층 및 연기유동 특성)

  • Rie, Dong-Ho;Kim, Ha-Young;Moon, Sung-Woong;Yoo, Ji-Oh
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.223-228
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    • 2009
  • The aim of this research is to analyse the dynamic characteristics of the hot upper smoke layer in case of fire in a tunnel. In order to get the result, computer simulation technique has been used. The fire scenarios were set on the basis of standard cross section of national and express highways through NIST's FDS. As the area of a tunnel increased, the influence of the wind velocity decreased. Furthermore, the influence of the slope of a road was reduced as the wind velocity increased. On the other hand, as the wind velocity increased, the influence of the slope of a road decreased. This phenomena is believed to be caused by the cooling effect of wind which is over 1 m/s in speed, hence, reducing the influence of the effect of slope.

A study on the efficiency advancement for evacuation of the crews by ship structural improvement (선박 구조 개선을 통한 승무원의 피난 효율 향상을 위한 연구)

  • Kim, Wonouk;Lee, Myoungho;Kim, Jongsu
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.342-348
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    • 2014
  • Onshore great fires can normally be extinguished by firefighters using special firefighting equipment and its suitable method. However, offshore fires on the ships are to be extinguished by the crew without any supports from the onshore. Also, crews working on board are exposed to high risk of emergency evacuation due to the complicated structure arrangement of the ships and different accident types such as fire and ship collisions. As most of damage and loss of life in fire are associated with suffocation, shortening of evacuation time is an important factor to improve a survival rate. In this study, visibility in the accommodation area is analyzed by using the temperature and smoke flow which are obtained by the Fire Dynamic Simulator(FDS) as a Three-Dimensional Fire Analysis program to understand the survival rate of the crew upon the fire. The fire doors for most of ships are designed to close automatically when the fire alarm is activated. These automatic closing of the fire doors is a very effective system to delay the spread of flame and smoke flow for the unmanned spaces of the fire protected area. However, if the crew cannot escape within the estimated time, the crew inside the fire protected area will be damaged a lot. In this paper, the comparative analysis between the evacuations by using the fire door from the fire protected area and the suggested fire shielding structure in this study is carried out by the smoke flow rate and the temperature rise rate.

Visualization of Roll Torque Generating Flows in a SRM Submerged-Nozzle by Cold Air-flow Test (내삽노즐 고체로켓모터의 공기 유동모사시험을 통한 롤토크 발생유동 가시화)

  • Kim, Do-Hun;Lee, In-Chul;Lee, Yeol;Koo, Ja-Ye;Kang, Moon-Jung;Kim, Yoon-Gon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.2
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    • pp.29-35
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    • 2011
  • The behaviors of combustion-induced internal flows of SRM equipped with fin-slot grain and submerged nozzle are very complex and diverse. Cold air-flow tests for 2D and 3D scale models of SRM have been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tubes also has been visualized through employing various light source and recording directions.

Visualization for Internal Flow of Submerged-Nozzle SRM by Cold Air-flow Test (내삽노즐 고체로켓의 공기 유동모사시험을 통한 내부유동 가시화)

  • Kim, Do-Hun;Cho, Yong-Ho;Lee, Yeol;Koo, Ja-Ye;Kim, Yoon-Gon;Kang, Moon-Jung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.181-185
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    • 2010
  • The behavior of combustion-induced internal flow of SRM equipped with fin-slot grain and submerged nozzle is very complex and diverse. Cold air-flow test for 2D and 3D scale models of SRM has been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tube also has been visualized through employing various light source and recording directions.

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A Study on the improvement the efficiency of the evacuation of the ship's crews (선박 승무원의 피난 효율 향상에 관한 연구)

  • Kim, Won-Ouk;Kim, Jong-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.153-154
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    • 2013
  • In this study, we used the program of three-dimensional analysis of fire for analyzing visibility of smoke flow and temperature of the accommodation area what is required for the analysis of survival of the crew. In particular, I would like to propose a method for reducing the flow rate performance in order to reduce the suffocation from the smoke of the majority of personal injury. Existing vessels are designed to close the fire door automatically when the fire alarm issued. When there is no crew that dared to escape, it can delay the spread of fire and smoke flow which is determined to be very useful to improve the survival rate of the crew. However, it can be fatal to the crew whose rooms are located on the inside of the fire door that has not completed the evacuation. In this study, we check the smoke flow rate and rate of temperature rise when crew open the fire door what is closed due to fire and compare to the structure of the blocking layer.

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A Study of Bore Evacuator Gas Flow Analysis (제연기 개스유동 해석에 관한 연구)

  • 강국정
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.1083-1087
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    • 1996
  • Bore evacuator which have circular structure of cylindrical form is located at tube, and its function is to evacuate toxic gases generated during firing intervals. Between bore evacuator and bore interior, gas flow field is developed through the nozzles, and the charging and discharging process is formed. By these flow cycle(charging and discharging) the evacuation effect can be generated. This report contains an analyses and results consideration about bore evacuator flowfield.

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A Study of Smoke Movement in an Enclosed Corridor. (밀폐된 복도 공간내의 연기 거동에 관한 연구)

  • 김성찬;유홍선;정진용;김충익
    • Fire Science and Engineering
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    • v.13 no.2
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    • pp.18-25
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    • 1999
  • There are a lot of works for predicting smoke movement in a building experimentally and m numerically. It is Vel${\gamma}$ important to predict a smoke movement in a corridor which is c connected to adjacent spaces. A numerical analysis of smoke movement in an enclosed c corridor is perlormed by a field model. The used field model is develo야d with 3-D u unstructured meshes, PISO Algorithm and buoyant plume model. In this study, tern야~ature a and flow field, some important p하ameters such as smoke spread time, hot layer temperature, c ceiling jet velocity were compared with experimental data which were perlormed in Korea I Ins디tute of Machinery and Materials. And average velocity of ceiling jet by this study is c compared with Hinkley's formula. This paper shows a flow characteristic around the soffit a and average velocity of ceiling jet is i따luenced by geometry of corridor, heat output, and d distance from the fire source.

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Uncertainty Analysis of the Optical Smoke Density Measurement through the Doorway in a Compartment Fire (구획화재의 출입구를 통한 광학적 연기밀도 측정의 불확실성 해석)

  • Kim, Sung-Chan
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.75-79
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    • 2013
  • The present study measured the light transmission to quantify the smoke density(smoke mass concentration) through the doorway in a compartment fire and performed the uncertainty analysis to evaluate the reliability of the measurement technique. The optical light extinction method based on Bourguer's law was applied to estimate the smoke density of doorway exhausting smoke flow in upper layer of a compartment for methane gas fires. The measurement uncertainty of the light extinction measurement was evaluated for the light transmittance, path length, and specific mass extinction coefficient and the expanded uncertainty was estimated about 20% with confidence level of 95%. The mean smoke density through the doorway for the methane fire was calculated for quasi-steady fire and the smoke density linearly increased as the GER increased.

A Study on the Smoke behavior and set-up of evacuation capacity in buildings at BRI2002 (BRI2002를 중심으로 한 건축물의 연기유동과 피난용량설정방안에 관한 연구)

  • Seo, Dong-Goo;Kim, Dong-Eun;Hong, Hae-Ri;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2010.04a
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    • pp.487-492
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    • 2010
  • 최근 건축물은 초고층화 대형화 지하심층화 등으로 변모하고, 더나아가 복합화가 진행되고 있다. 이러한 건축물은 화재 발생 시 기존의 건축물보다 큰 인재로서 다가오며, 특히 연기로 인한 피해가 주를 이루고 있다. 하지만 국내의 경우 연기의 피해에 따른 피난용량설정 및 계획 등에 관한 연구가 미흡한 실정이다. 따라서 본 연구는 이에 대하여 일본의 BRI2002 모델의 알고리즘분석에 따른 피난 안전과의 연계성 방안을 도출하여, 향후 국내의 연기를 중심으로한 피난용량설정방안에 대하여 서술하였다.

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