• Title/Summary/Keyword: Fire Spread Speed

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Analysis of Forest Fire Spread Rate and Fire Intensity by a Wind Model (모형실험에 의한 풍속변화에 따른 산불의 확산속도와 강도 분석)

  • 채희문;이찬용
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.4
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    • pp.213-217
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    • 2003
  • Forest fire spread and intensity were modeled as a function of wind and fuel. Spread rate and intensity of forest fire were related to weight and thickness of forest fuel beds and to wind speed. Forest fire spread rate and fire intensity were differentiated according to wind speed. Rapid wind speed causes a faster forest fire spread rate and greater fire intensity than does slow wind speed. Relative burning time of the fire from beginning to end in the model was 161 sec at a wind speed of 0.5 m/sec and 146 sec at 1m/sec on the model. Average forest lire spread rate was 0.014 m/sec at a wind speed of 0.5 m/sec and 0.020 m/sec at 1m/sec. Average fire intensity was 0.183 ㎾/m at a wind speed of 0.5 m/sec, 0.259 ㎾/m at 1m/sec. Fire intensity was greater when forest fire spread rate was rapid.

A Study on Block from Spread of Fire of the Exteriors Installation Space (외장재 설치 공간의 화재확산 차단에 관한 연구)

  • Min, Se-Hong;Yun, Jung-Eun;Kim, Mi-Suk
    • Journal of the Korea Safety Management & Science
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    • v.14 no.2
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    • pp.83-89
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    • 2012
  • In this study, FDS fire simulation experiments and measured wind speed by applying the exterior installation portion for blocking the spread of the fire was investigated. As a result, aluminum composite panels installed in the lower and the upper part of the panel to remove all the lower side, and then the maximum wind speed 0.24 m/s and the upper side 0.58 m/s were measured. In the FDS, the measured wind speed difference air currents are approximately 3.7 times in 12 seconds, the occurrence of 17 seconds early moment wind 2.2 m/s was measured from. Before and after the fire occurred in early of the air velocity about 39 seconds was 3.5 times difference. Such air currents caused by the temperature of the building but also by the building height was found. Turbulent flame of fire by expanding the vertical extent of damage become greatly important factor. Therefore, through the exterior installation portion of the block that can delay the spread of fire is expected that this should be taken.

Developing of Slope Calculation Algorithm for Forest Fire Spread Modeling (산불확산모델링에 적합한 경사계산 알고리즘 개발)

  • An, Sang-Hyun;Kang, Yong-Seok;Son, Young-Gi;Lee, Si-Young;Shin, Young-Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.2
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    • pp.122-128
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    • 2007
  • GIS is used much research for efficient forest fire management and forecasting and slope has been known as high-leverage thing in spread of forest fire specially. Various algorithms are used usually to calculate slope angle of topography from DEM(Digital elevation model). However, because spread speed of forest fire is different according to uphill slope and downhill slope, it need new slope calculation algorithm. Therefore, developed slope calculation algorithm can reflect uphill slope and forest fire spread speed of looking downhill slope.

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Evaluation on Fire Spread Speed of Standard Rack in Korea for Performance based Fire Extinguishing System (성능위주 소화설비 적용을 위한 표준랙크의 화재확산속도 평가)

  • Cho, Gyu-Hwan;Yeo, In-Hwan
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.84-91
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    • 2016
  • In case of fire, vertically and intensively loaded rack warehouses are faced with a severe status due to the rapid increase in fires. In this regard, there have been trials to prevent fires from spreading by applying fire extinguishing systems, such as ESFR and In-Rack Sprinklers, vertical and horizontal barriers, etc.; however, it is difficult to calculate and design proper fire extinguishing systems caused by various composition conditions, such as the size and loading density of the rack, types of loading commodities, etc. Therefore, in this study, a standard rack was manufactured, incorporating a rack warehouse in Korea by site investigations, surveys, etc. In addition, a full scale fire test was executed to check the fire characteristics depending on the conditions of the ignition points. As a result, the extracted fire spread speed is expected to be utilized as a reference for performance comparisons of the fire extinguishing systems to be developed and applied in the future.

Spread Speed of Forest Fire based on Slope (경사에 따른 산불의 확산속도)

  • An, Sang-Hyun;Shin, Young-Chun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.4
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    • pp.75-79
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    • 2008
  • As Information Technology developed, Information requirement has been went higher. In the field of GIS(Geographic Information System) more information is processed more quickly and accurately. Especially, quick analysis of forest fire information (topography, ignition point, weather condition, etc.) over a wide area is essential in order to minimize victim, environmental damage, and economical damage, decide course of evacuating, estimate a fire spread course, and attack resource arrangement. We determined a fire spread distance at each unit time through an experiment with various slope degrees and distinction of flat, upslope and downslope. For the tests on the upslope, as the slope increased, the rate of spread increased. On the downslope in contrast with the upslope, as the slope increased, the rate of spread decreased. We analyzed a spread rate of forest fire on each slope as the method classified upslope(+) and downslope(-) using the results obtained from the experiment. Consequently, the proposed method is able to be used to effectively support the attack of forest fire by providing accurate predictions of fire spread.

ANALYSIS OF SMOKE SPREAD EFFECT DUE TO THE FIRE STRENGTH IN UNDERGROUND SUBWAY-STATION (대심도 역사의 화재강도에 따른 연기확산 영향 분석)

  • Jang, Yong-Jun;Koo, In-Hyuk;Kim, Hag-Beom;Kim, Jin-Ho
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.373-378
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    • 2011
  • As the number of deeply-underground subway station(DUSS) increases, the safety measures for DUSS have been requested. In this research, Shingumho station (The line # 5, Depth: 46m) has been selected as case-study for the analysis of smoke-spread speed with the different fire strength. Field test data measured for actual fan in DUSS was applied as a condition of a simulation. The whole station was covered in this analysis and total of 4 million grids were generated for this simulation. The fire driven flow was analyzed case by case to compare the smoke-spread effect according to the fire strength. in order to enhance the efficiency of calculation, parallel processing by MPI was employed and large eddy simulation method in FDS code was adopted.

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Semi-numerical Study on the Flame Tilt Equation due to Wind on the Surface Fire in Forest Fire (산불 지표화에서의 바람에 의한 화염각 변화 산정식 도출에 관한 준-수치해석 연구)

  • Kim, Dong-Hyun
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.90-95
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    • 2009
  • The wind is very important factor in forest fire spread. Flame spread has a change through wind pattern change in forest fire. In order to analyze the forest fire flame spread rate, change of flame tilt depending on wind may be considering first. This is be cause the flame spread rate varies by the flame tilt changed due to transfer of heat. Especially, as wind speed grow, flame gets closer to surface, heat transfer ratio increase, virgin fuel bed reaches ignition temperature more rapidly, and flame moves faster. This study deduces, through experiment and physical figure analysis, relations on the change behavior of flame tilt due to wind. The value of flame tilt angle calculated from the equation and the experiment value showed average error angle of $3.3^{\circ}$, which is relatively smaller than results of previous studies that used other coefficient. Froude number coefficient A can be calculated in the method provided in this research for estimation of flame tilt angle of virgin fuel bed with varying thermal properties. The research finding is expected to be applied to future studies on flame spread through numerical analysis of heat transfer.

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.

Application of Horizontal Barrier on a Rack to Reduce Fire Spread (화재확산 저감을 위한 랙크 내 수평차단막 적용에 관한 연구)

  • Yeo, In-Hwan;Cho, Gyu-Hwan
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.71-79
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    • 2017
  • A rack warehouse with a vertically loading type and high loading density has severe risks and damage during its fire. In this regard, US and Japan strive to minimize the fire spread by applying in-rack sprinkler, horizontal barriers, etc. corresponding to their own rack warehouse but there is no study and policy in Korea. Therefore, a model scale fire test was carried out targeting the standard rack incorporating the national rack warehouse in order to check fire characteristics in ignition points and installation distances of horizontal barriers in this study. As a result of the test, vertical fire spread of about 30% was inhibited by narrowing its installation distance from 2-layer to 1-layer in an ignition condition of the flue space. In addition, as a result of the measurement of the temperature in the upper and lower parts of the horizontal barrier, the temperature distribution showed about 2~4 higher in a condition with an installation of the barrier than that in the condition without the barrier. Consequently, it is likely that the horizontal barrier will help the initial operation of in-rack sprinkler.

A FORECASTING METHOD FOR FOREST FIRES BASED ON THE TOPOGRAPHICAL CLASSIFICATION SYSTEM AND SPREADING SPEED OF FIRE

  • Koizumi, Toshio
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.311-318
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    • 1997
  • On April 27,1993, a forest fire occurred in Morito-area, Manba-city, Gunma-prefecture Japan. Under the prevailing strong winds, the fire spread and extended to the largest scale ever in Gunma-prefecture. The author chartered a helicopter on May 5, one week after the fire was extinguished, and took aerial photos of tile damaged area, and investigated the condition. of the fire through field survey and data collection. The burnt area extended. over about 100 hectares, and the damage amounted to about 190 million yen (about two million dollar). The fire occurred at a steep mountainous area and under strong winds, therefore, md and topography strongly facilitated the spreading, It is the purpose of this paper to report a damage investigation of the fire and to develop the forecasting method of forest fires based on the topographical analysis and spreading speed of fire. In the first place, I analyze the topographical structure of the regions which became the bject of this study with some topographical factors, and construct a land form classification ap. Secondly, I decide the dangerous condition of each region in the land form classification map according to the direction of the wind and spreading speed of f'kre. In the present paper, I try to forecast forest fires in Morito area, and the basic results for the forecasting method of forest fires were obtained with the topographical classification system and spreading speed of fire.

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