• Title/Summary/Keyword: flame spread

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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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Experimental Study on the Flash Over Delay Effects according to the Prevention of Flame Spread between Composite Material Panels (복합자재의 패널 간 화염확산방지에 따른 플래시오버 지연 효과에 대한 실험적 연구)

  • Kim, Do-hyun;Cho, Nam-Wook
    • Fire Science and Engineering
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    • v.31 no.2
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    • pp.1-8
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    • 2017
  • A sandwich panel is a composite material composed of a double-sided noncombustible material and insulation core which is used in the inner, outer walls, and roof structure of a building. Despite its excellent insulation performance, light weight and excellent constructability, a flame is brought into the inside of the panel through the joint between the panels, melting the core easily and causing casualties and property damage due to the rapid spread of flame. The current Building Law provides that the combustion performance of finishing materials for buildings should be determined using a fire test on a small amount of specimen and only a product that passes the stipulated performance standard should be used. This law also provides that in the case of finishing materials used for the outer walls of buildings, only materials that secured noncombustible or quasi-noncombustible performance should be used or flame spread prevention (FSP) should be installed. The purpose of this study was to confirm the difference between the dangers of horizontal and vertical fire spread by applying FSP, which is applied to finishing materials used for the outer walls of buildings limitedly to a sandwich panel building. Therefore, the combustion behavior and effects on the sandwich panel according to the application of FSP were measured through the construction to block the spread of flame between the panels using a full scale fire according to the test method specified in ISO 13784-1 and a metallic structure. The construction of FSP on the joint between the panels delayed the spread of flame inside the panels and the flash over time was also delayed, indicating that it could become an important factor for securing the fire safety of a building constructed using complex materials.

Effects of Flame Transfer Function on Modeling Results of Combustion Instabilities in a 3 Step Duct System (3단 덕트 시스템에서 화염전달함수가 연소불안정 모델링 결과에 미치는 영향)

  • Hong, Sumin;Kim, Daesik
    • Journal of ILASS-Korea
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    • v.25 no.3
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    • pp.119-125
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    • 2020
  • In this paper, we used Helmholtz solver based on 3D finite element method to quantitatively analyze the effects of change of gain, time delay and time delay spread, which are the main variables of flame transfer function, on combustion instability in gas turbine combustor. The effects of the variable of flame transfer function on the frequency and growth rate, which are the main results of combustion instability, were analyzed by applying the conventional heat release fluctuation model and modified one considering the time spread. The analysis results showed that the change of gain and time delay in the same resonance mode affected the frequency of the given resonance modes as well as growth rate of the feedback instability, however, the effect of time delay spread was not relatively remarkable, compared with the dominant effect of time delay.

A Numerical Study of the Effect off Fire Growth Model on Fire Characteristics in a Carriage (화재 성장 모델이 객차내 화재 특성에 미치는 영향에 관한 수치해석적 연구)

  • 김성찬;유홍선;최영기;김동현
    • Journal of the Korean Society for Railway
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    • v.7 no.3
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    • pp.180-185
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    • 2004
  • The present study investigates the effect of fire growth model on fire development characteristics in a carriage. The parallel processing version of FDS code is used to simulate the fire driven flow in a carriage and two types of fire growth model which are flame spread model and t$^2$ model are examined for the same geometrical condition. The heat release rates(HRR) of both model are similar each other until 30 s after ignition, but the flame spread model predicts 5 times higher than those of the t$^2$ fire model during the quasi-steady fire period. Maximum heat release rate in the case of flame spread model reaches about to 12 MW at 100 s after fire ignition. Also, various database of fire properties for combustible materials and more elaborate combustion model considering the flame spreading phenomena are required for better predictions of fire development characteristics using numerical simulation.

A Study on the Flame Retardant Effect for Metal Complexes-Cellulose Hybrid Insulator (금속착물-셀룰로오스 복합 단열재의 난연 효과 연구)

  • Kim, Hong;Kang, Young-Goo
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.62-67
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    • 1995
  • The combustion characteristics of cellulose Insulation treated with several metal complexes such as Aluminium hydroxide, Cupric sulfate pentahydrate, Magnesium sulfate heptahydrate, Manganese chloride tetrahydrate and Tnisodium phosphate dodecahydrate are studied to evaluate the effectiveness as a potential flame retardant for cellulosic materials. In this study, we found that LOI values of cellulosic materials treated with the metal complexes are generally increased with the increase of their content. At high concentration, CS(24% ) and SP(24% ) show high LOI values, suggesting resistance to flame spread, The materials examined in this study were found to be relatively more resistance to smouldering and flaming combustion in comparision with untreated cellulosic material. The flammability behavior of the materials exhibits combustion process as follows : LOI$\rightarrow$smouldering region$\rightarrow$smouldering-flaming spread region$\rightarrow$flame spread region.

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An Experimental Study on the Risk of Vertical Flame for a Extended-Balcony (발코니 확장에 따른 수직화염 확대 위험성에 관한 실험적 연구)

  • Shin, Yi-Chul;Youn, Yoo-Hyuk;Lee, Ju-Hee;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.283-288
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    • 2008
  • Since installing a balcony can significantly reduce the spread of fire, fire spread to the upper levels was confirmed, comparing the cases with and without balcony extension. It was confirmed that the fire can spread not only to the next higher level but also to two levels higher due to the outburst of flame which reached a significant temperature in the case without balcony, while the possibility of fire spread to the upper level reduced considerably with the balcony. this study is compared and analyzed to vertical diffusion appearance of an externally venting flame. An installed balcony is also applied to fire test 6.54kW to analyze about effect of a balcony.

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A Room-Corner Fire Model을 적용한 건축내장재의 화재확산 특성 평가(1)

  • Kim, Un-Hyeong
    • Fire Protection Technology
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    • s.24
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    • pp.32-39
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    • 1998
  • A room-corner fire scenario of ISO 9705 with flame spread model developed by Quintiere is applied to the interior finish materials to show the sensitivity of properties derived from AST, E-1321 and ASTM E-1354 is investigated and various range of thermal properties by the author were analyzed in the model. There are including flame heat flux and thermal inertia, lateral flame spread parameter, heat of combustion and effective heat of gasfication. The time for total energy release rate to reach 1MW is examined. Though some areas are neede for improvements, The model appears to predict good results with all the range of input properties and could be

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Experimental Study on Effect of AC Electric Field on Upwardly Spreading Flame over Polyethylene insulated Electrical Wire (폴리에틸렌으로 피복된 전선을 통해 위로 전파하는 화염에 대한 교류전기장 효과에 대한 실험적 연구)

  • Lim, Seungjae;Kim, Minkuk;Park, Jeong;Chung, Sukho;Fujita, Osamu
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.363-365
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    • 2014
  • An experimental study on effect of AC electric field on upwardly spreading flame over electrical wire, which is insulated by Polyethylene(PE), was conducted. The result showed that upwardly spreading flame leaned toward unburned side with angle of inclination. With applied electric field, size of upwardly spreading flame increased significantly. Flame spread rate showed various trends with inclination, applied voltage and frequency.

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An Experimental Study on the Application of Horizontal Barrier and In-Rack Sprinklers to Prevent Vertical Spread of Rack-type Warehouse Fires (랙크식 창고 화재의 수직 확산 방지를 위한 수평차단막과 In-Rack 스프링클러 적용에 관한 실험연구)

  • Park, Moon-Woo;Hong, Sung-Ho;Choi, Ki-Ok;Choi, Don-Mook;Kim, Soo-Jin
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.15-21
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    • 2019
  • A rack-type warehouse has the advantage of storing a large amount in a small area by loading goods vertically. But in terms of fire risk, the fire load is very high, which can cause massive damage in the event of a fire. In the United States, research has been actively conducted to minimize the spread of vertical fires, and relevant standards have been established and operated. In Korea, research and related standards are insufficient to prevent the vertical spread of rack-type warehouse fires. In this study, an experimental study was conducted to prevent the vertical spread of a rack-type warehouse fire using a horizontal barrier and in-rack sprinklers. As a result of the test, the horizontal barrier considering the continuous flame prevented the vertical spread of the flame for a certain time. However, the horizontal barrier with continuous flame did not show the effect of preventing continuous flame. The combination of the horizontal barrier and the in-rack sprinkler prevented the vertical spread of fire effectively. In addition, the heat collecting effect through the horizontal barrier was shown and helped the early operation of the in-rack sprinklers.

Experimental Study on Spreading Flame over Slanted Polyethylene Insulated Electrical Wire with AC Electric Field (전기장이 인가된 상태에서 폴리에틸렌으로 피복된 기울어진 전선을 통해 전파하는 화염에 대한 실험적 연구)

  • Lim, Seungjae;Kim, Minkuk;Park, Jeong;Chung, Sukho;Fujita, Osamu
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.187-190
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    • 2014
  • An experimental study on downwardly and upwardly spreading flames over slanted electrical wire, which is insulated by Polyethylene(PE), was conducted with applied AC electric field. The result showed that downwardly and upwardly spreading flames with angle of inclination leaned toward burnt side and unburned side, respectively. With applied AC electric fields, size of downwardly spreading flame decreased slightly and that of upwardly spreading flame increased significantly. Flame spread rate showed various trends in terms of inclination, applied voltage and frequency.

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