• Title/Summary/Keyword: Wind & Fire

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A STUDY on FOREST FIRE SPREADING ALGORITHM with CALCULATED WIND DISTRIBUTION

  • Song, J.H.;Kim, E.S.;Lim, H.J.;Kim, H.;Kim, H.S.;Lee, S.Y
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.305-310
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    • 1997
  • There are many parameters in prediction of forest fire spread. The variables such as fuel moisture, fuel loading, wind velocity, wind direction, relative humidity, slope, and solar aspect have important effects on fire. Particularly, wind and slope factors are considered to be the most important parameters in propagation of forest fire. Generally, slope effect cause different wind distribution in mountain area. However, this effect is disregarded in complex geometry. In this paper, wind is estimated by applying computational fluid dynamics to the forest geometry. Wind velocity data is obtained by using CFD code with Newtonian model and slope is calculated with geometrical data. These data are applied fer 2-dimentional forest fire spreading algorithm with Korean ROS(Rate Of Spread). Finally, the comparison between the simulation and the real forest fire is made. The algorithm spread of forest fire will help fire fighter to get the basic data far fire suppression and the prediction to behavior of forest fire.

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Experimental Study on Heat Flow According to the Wind Velocity in an Underground Life Space (지하생활공간 화재시 풍속에 따른 열유동 특성 연구)

  • Kim, Young-No;Suk, Chang-Mok;Kim, Wha-Jung
    • Fire Science and Engineering
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    • v.21 no.3
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    • pp.61-68
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    • 2007
  • The purpose of this study analyzes heat flows and fire behavior through a reduced-scale model experiments about change of wind velocity in underground life space. When the wind velocity is increased the temperature rise time of the fire room was risen fast. And temperature of fire room was increased. And increase of wind velocity displayed maximum temperature at an opening of the fire room. Heat flows by fire spread increase size of smoke occurrence and flame, and displayed high temperature distribution in passageway than inside of neighborhood department promoting eddy flow spread as wind velocity increases. Finally, heat flows are decided by wind and wind velocity at fire of underground life space, and Wind velocity increases, temperature increase and decrease could confirm that is gone fast.

Computational study of road tunnel exposure to severe wind conditions

  • Muhic, Simon;Mazej, Mitja
    • Wind and Structures
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    • v.19 no.2
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    • pp.185-197
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    • 2014
  • Ventilation and fire safety design in road tunnels are one of the most complex issues that need to be carefully considered and analysed in the designing stage of any potential upgrade of ventilation and other fire safety systems in tunnels. Placement road tunnels space has an important influence on fire safety, especially when considering the effect of adverse wind conditions that significantly influence ventilation characteristics. The appropriate analysis of fire and smoke control is almost impossible without the use of modern simulation tools (e.g., CFD) due to a large number of influential parameters and consequently extensive data. The impact of the strong wind is briefly presented in this paper in the case of a longitudinally ventilated road tunnel Kastelec, which is exposed to various severe wind conditions that significantly influence its fire safety. The possibility of using CFD simulations in the analysis of the tunnel placement in space terms negative effect of wind influence on the tunnel ventilation is clearly indicated.

Study on Sensitivities and Fire Area Errors in WRF-Fire Simulation to Different Resolution Data Set of Fuel and Terrain, and Surface Wind (WRF-Fire 산불 연료 · 지형자료 해상도와 지상바람의 연소면적 모의민감도 및 오차 분석연구)

  • Seong, Ji-Hye;Han, Sang-Ok;Jeong, Jong-Hyeok;Kim, Ki-Hoon
    • Atmosphere
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    • v.23 no.4
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    • pp.485-500
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    • 2013
  • This study conducted WRF-Fire simulations in order to investigate sensitivities of the resolution of fire fuel and terrain data sets, and the surface wind to simulated fire area. The sensitivity simulations were consisted of 8 different WRF-Fire runs, each of which used different combination of data sets of fire fuel and terrain with different resolution. From the results it was turned out that the surface wind was most sensitive. The next was fire fuel and then fire terrain. Unfortunately, every run produced too much fire area. In other words no simulations succeeded in simulating such proper fire area so as for the WRF-Fire to be used realistically. It was verified that the errors of fire area from each runs were contributed by 41%, 53%, and 6% from surface wind, fire fuel, and fire terrain, respectively. Finally this study suggested that the selection of Anderson fuel category in the area of interest seemed to be very critical in the performance of WRF-Fire simulations.

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.

Study on ${\ulcorner}$Medical Records as a Guide to Clinical Works${\lrcorner}$ ${\ulcorner}Volume\;1{\lrcorner}$ ${\ulcorner}dizziness{\lrcorner}$ ("임증지남의안(臨證指南醫案)"권일(卷一) "현운(眩暈)"에 대한 고찰)

  • Shin, Soon-Shik
    • Journal of The Association for Neo Medicine
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    • v.1 no.2
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    • pp.31-37
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    • 1996
  • ${\ulcorner}Volume\;1{\lrcorner}$ of ${\ulcorner}$Medical Records as a Guide to Clinical Works${\lrcorner}$, written by Ye Tian Shi, showed some clinical cases of dizziness. In this study, his diagnosis and treatment was studied with 16 clinical cases of dizziness with pathogenic factor, pathogenesis and symptoms of dizziness. Ye Tian Shi thought that phlegm, fire, wind and insufficiency were the causes of dizziness and phlegm-fire, phlegm-fire-wind, wind-phlegm and insufficiencyfire-wind were the causes of dizziness, clinically. Dizziness is caused when the body is in condition of excess in the upper and deciency in the lower. The acompanying clinical symptoms of dizziness are endogenous wind, fire of deficiency type, phlegm wind and phelegm fire. For the treatment of dizziness, Ye Tian Shi used the combination of medicines with some modifications by the cases for phlegm, fire, wind and insufficiency. He also encouraged the mental therapy for the treatment of dizziness. He emphasized the early treatment of dizziness to prevent hemiplegia after apoplexy. It can be postulated from Volume 1 of ${\ulcorner}$Medical Records as a Guide to Clinical Works${\lrcorner}$, diagnosis and treatment of symptoms and illness of Ye Tian Shi was strictly based on actual clinical cases.

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The Influence of Wind Conditions on the Performance of Smoke Ventilation in High-rise Building Fires (초고층건물 화재시 외기바람이 배연성능에 미치는 영향)

  • Kim, Beom-Gyu;Yim, Chae-Hyun;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.63-73
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    • 2016
  • This study examined the effects of the wind conditions, such as wind velocity and wind directions, on the performance of the mechanical smoke exhaust systems for high-rise building fires. A scaled model design and CFD simulations were used to verify the effects both quantitatively and qualitatively. The results showed that the smoke exhaust velocity of the mechanical exhaust system can be reduced by up to 17% at a wind velocity of 5 m/s (equivalent to an outdoor wind speed of 16 m/s) and a wind direction of ${\theta}=5^{\circ}$. In addition, the angle of the outdoor wind direction below ${\theta}=25^{\circ}$ had a significantly influence on the smoke exhaust flow rate and reduced exhaust performance of the smoke exhaust system in a fire.

NUMERICAL SIMULATION OF WIND-DRIVEN FIRE FLUMES

  • Kohyu Satoh;Yang, K.T.
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.327-334
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    • 1997
  • In many large urban-fire scenarios one of the critical issues is to attempt to protect the lives of fire fighters in helicopters deployed to flying over the fires and also the lives of people trapped in open areas downwind of the fires such as in parks. The strategies of such protection measures depend significantly on our knowledge of the size and extent of such fires as affected by the prevailing winds. In this study, the shape or profile of the fire plume typical of large urban fires, as affected by a steady unidirectional wind with or without imposing a shear flow on the fire plume, has been simulated numerically by a field model. The results show that the simulations provide realistic flame profiles and at least qualitatively, the same flame dynamics when compared to those from the experiments, and that the fire plumes are sensitive to small variations in the asymmetry of the wind shears, including the appearance of swirling flames within the fire plumes.

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Methods for Early Fire Detection and Fire Position Determination Inside the Nacelle of Wind Turbine Generator System (풍력발전기 나셀 내부 화재 조기감지 및 화재 위치 판별 방법)

  • Kim, Da Hee;Lim, Jong Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.12
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    • pp.935-943
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    • 2015
  • This paper presents a method for early fire detection and fire position determination inside the nacelle of wind turbine generator system. The rising temperature and obscuration rates inside the nacelle were used as parameters for fire detection, which can minimize the possibility of a fire detection malfunction because these rising rates do not depend on the absolute values of temperature and obscuration. The fire position was determined using the time difference among various sensor positions for fire detection. The performance of the method was tasted using sets of experiments in a nacelle simulator.

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.