• Title/Summary/Keyword: fire spread

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A Numerical Study on the Effects of the Wind Velocity and Height of Grassland on the flame Spread Rate of Forest Fires (초지화재 발생시 바람의 속도 및 초본의 높이가 화염전파에 미치는 영향에 대한 수치해석적 연구)

  • Bae, Sung-Yong;Kim, Dong-Hyun;Ryou, Hong-Sun;Lee, Sung-Hyuk
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.252-257
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    • 2008
  • With the rapid exuberant growth of the forest, the number and size of forest fires and the costs of wildland fires have increased. The flame spread rate of forest fires is depending on the environmental variables like the wind velocity, moisture of grassland, etc. If we know the effects of the environmental variables on the fire growth, it is useful for wildland fiIre suppression. But analysis of the spread rate of wildland fire for these effects have not been established. In this study, the effects of wind velocity and height of grassland fuel have been investigated using the WFDS which is developed at NIST for prediction of the spread of wildland fires. The results showed that the relation between the height of the fuel and the spread rate of the head fires is, and the spread rates related to the wind velocity are predicted 17% less than the experimental results of Australia. When the wind velocity is over 7.5m/s, the concentration of pyrolyzed gas phase fuel is getting low due to fast movement of pyrolyzed gas, the flame spread rate becomes slow.

The Theory of Smoke Movement by a Fire in an Enclosure (밀폐공간에서의 화재에 의한 연기의 유동 이론)

  • 노재성;유홍선
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1996.11a
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    • pp.5-9
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    • 1996
  • In foreign country such as U.S.A and Japan, considerable research has been done regarding the spread of smoke in room of fire involvement by using computer. But, in our country it has not been. So, this paper presents a detailed qualitative description of phenomena which occures during typical fire scenarios through numerical analysis. This research, in the view of field model, is focused on finding out the smoke movement and temperature distribution. And it is planned to analyze governing equation including smoke diffusion equation by numerical analysis with finite volume method and non-staggered grid system. The SIMPLE method for pressure-velocity couple and power-law scheme for convection terms are used. It shows that a plume is formed, hot plume is formed, hot plume gases impinge on the ceiling and they spread across it. then, it eventually reaches the bounding walls of the enclosure. It takes 60s for smoke to fill the enclosure.

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An Experimental Study on Smoke Spread Using a Reduced-scale Subway Building Model (지하역사 축소모델을 이용한 연기확산에 대한 실험적 연구)

  • Kim, Myung-Bae;Choi, Byung-Il
    • Fire Science and Engineering
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    • v.22 no.2
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    • pp.49-56
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    • 2008
  • Smoke propagation for the Daegu Metro fire is reproduced by a reduced-scale model experiment. The three-story station building was modeled with 1/20-scale, and the tunnel connected to the platform was not completely modeled because of its length. To include the flow resistance the tunnel provides the mesh screens were used in the model. The fire scenario was selected based on the fire growth rate of the metro car seat where the fire initiated. The time when smoke arrived at each compartment in the station building was measured by thermocouples and visualization. Regarding fire ventilation, the air supply that has been accepted as conventional design in a subway metro building intensifies smoke spread. The results show that the whole building was filled with smoke in about 10 minutes in case of no ventilation.

The Design and Implementation of Mobile Application Solution for Forest Fire based on Drone Photography and Amazon Web Service (AWS)

  • Choi, Si-eun;Bang, Jong-ho
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.31-37
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    • 2020
  • Last year's Goseong-Sokcho forest fires have highlighted the limitations of extinguishing work for night-time forest fire and the importance of quick identification for information on the spread of forest fire. However, it is not easy to find services that take into account the characteristics of forest fires, as most existing disaster-related mobile applications and research assume various disaster situations rather than just forest fire situations. Therefore, a system that can provide information quickly is needed, taking into account the characteristics of forest fires and the limitations of extinguishing work. In this paper, we propose evacuation route guidance services that bypass areas where fire has already spread, supplement existing methods of extinguishing work, and provide general information on forest fire situations in real time, by putting drones into forest fire situations. It has been implemented to automate image analysis using the Rekognition service of Amazon Web Service (AWS), and the results of fire detection and the T Map API guide the evacuation path. It is expected that the results of this paper will allow efficient and rapid rescue and extinguishing work to be carried out, and further reduce the damage of human life caused by forest fires.

Localization Strategy of Building Fire Following Earthquake Risk Assessment Method (건축물 지진화재위험도 평가기법의 국산화 전략)

  • Kang, Taewook;Kim, Subin;Kim, Ye-eun;Kang, Jaedo;Kim, Haewon;Shin, Jiuk
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.3
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    • pp.57-69
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    • 2023
  • In this study, in order to establish a strategy for developing an fire following earthquake risk assessment method that can utilize domestic public databases(building datas, etc.), the method of calculating the ignition and fire-spread among the fire following earthquake risk assessment methodologies proposed by past researchers is investigated After investigating and analyzing the methodology used in the HAZUS-MH earthquake model in the United States and the fire following earthquake risk assessment methodology in Japan, based on this, a database such as a domestic building data utilized to an fire following earthquake risk assessment method suitable for domestic circumstances (planned) was suggested.

A Study on Risk Analysis by Type of Ceiling Material Based on Fire Theory (화재이론에 기초한 천장재 종류별 위험성 분석에 관한 연구)

  • Kim, HyeWon;Kim, YunSeong;Lee, ByeongHeun;Jin, SeungHyeon;Koo, InHyuk;Kwon, YoungJin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.116-117
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    • 2021
  • In general, when a building fire occurs, the heat flow rises by buoyancy, which affects the temperature rise of the ceiling. In addition, when the ceiling ignites, the fire spreads rapidly due to horizontal spread and radiant heat. According to the fire investigation, most of the large fires have a common characteristic that the fire spreads to the ceiling and causes many casualties. Therefore, it is considered that it is necessary to review the fire risk of ceiling materials used in buildings to prevent the spread of fire to the ceiling. Therefore, in this study, combustion characteristics such as the amount of heat released and ignition time of each SMC, DMC, and gypsum board were checked using a Cone Calorimeter, and the ignition temperature was calculated by substituting them into the fire theory. As a result, the ignition temperature of SMC was 449K, that of DMC was 1492K, and that of gypsum board was 677K.

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UPWARD FLAME SPREAD ON PRACTICAL WALL MATERIALS

  • Kim, Choong-Ik;Ellen G. Brehob;Anil K. Kulkarni
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.138-145
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    • 1997
  • Models of upward flame spread have been attempted in the past, but in the current work an emphasis has been placed on developing a practical model that will be useful across a broad range of materials. Some of the important aspects of the model we: the addition of external radiation to simulate a wall that is a part of an enclosure fire and has flaming walls radiating to it, the use of a correlation for flame heat feedback distribution to the sample surface based on data available in the literature, and the use of an experimentally measured mass loss rate for the sample material, In this paper, the development of the numerical model is presented along with predictions of flame spread for three materials: hardboard, a relatively homogeneous wood-based material; plywood, which is made of laminated wood bonded by adhesives; and a composite material made of fiberglass matrix embedded in epoxy. Predictions are compared with measured data at several levels of external radiation for each material. For the materials tested, the model correctly predicts trends and does a reasonable job predicting flame heights. The need for thermal property data for practical materials, which would be appropriate for flame spread models, is indicated by this work.

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Study on the Deep Stead Fire Spread Temperature by the Change of the Wood Flour Density (목분의 밀도변화에 따른 온도전이에 관한 실험적 연구)

  • Kim, Jin Su;Rie, Dong Ho
    • Fire Science and Engineering
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    • v.29 no.3
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    • pp.1-5
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    • 2015
  • The productivity and demand of porous material has been increasing by development of industry and increasing income. In particular, the fire caused by using wood flour risks wood processing industry and stock farm. The heat transfer of wood flour is carried into the depth direction by effect of oxidizer around flame, flame sometimes is progressed as smoldering. In the case of progressing as combustion fire, identifying the location of fire is difficult, and it leads to failing fire aid fire fighting. Therefore potential cause is acted as raising additional damage. This paper conducts experiments of downward deep seated fire of natural convection conditions. The samples is New Zealand wood flour that is demanded much in the domestic and oversea market. In this experiment, temperature of deep seated side is measure by changing wood flour density in holder The densities used in experiment are 3%, 5%, 10%, 15%. As a result, the tendency of temperature inside decreases as wood flour density increases. But, in the case of density which is above $0.2140g/cm^3$, the phenomenon, decreasing temperature, is not shown. The result of measurement show that average flame spread speed of wood flour is 0.249 mm/min.