• Title/Summary/Keyword: fire effects

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Effects of Ventilation Condition on the Fire Characteristics in Compartment Fires (Part I: Performance Estimation of FDS) (구획화재에서 환기조건의 변화가 화재특성에 미치는 영향(Part I: FDS의 성능평가))

  • Hwang, Cheol-Hong;Park, Chung-Hwa;Ko, Gwon-Hyun;Lock, Andrew
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.131-138
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    • 2010
  • Experimental and numerical studies were conducted to investigate the thermal and chemical characteristics of heptane fires in a full-scale ISO 9705 room. Representative fire conditions were considered for over-ventilated fire (OVF) and under-ventilated fire (UVF). Fuel flow rate and doorway width were changed to create OVF and UVF conditions. Detailed comparisons of temperature and species concentrations between experimental and numerical data were presented in order to validate the predictive performance of FDS (Fire Dynamic Simulator). The OVF and UVF were explicitly characterized with distributions of temperature and product formation measured in the upper layer, as well as combustion efficiency and global equivalence ratio. It was shown that the numerical results provided a quantitatively realistic prediction of the experimental results observed in the OVF conditions. For the UVF, the numerically predicted temperature showed reasonable agreement with the measured temperature. The predicted steady-state volume fractions of $O_2$, $CO_2$, CO and THC also agreed quantitatively with the experimental data. Although there were some limitations to predict accurately the transient behavior in terms of CO production/consumption in the UVF condition, it was concluded that the current FDS was very useful tool to predict the fire characteristics inside the compartment for the OVF and UVF.

Comparison of the Flame Height of Pool Fire according to Combustion Models in the FDS (FDS의 연소모델에 따른 풀화재의 화염높이 비교)

  • Han, Ho-Sik;Hwang, Cheol-Hong;Oh, Chang Bo;Choi, Dongwon;Lee, Sangkyu
    • Fire Science and Engineering
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    • v.32 no.3
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    • pp.42-50
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    • 2018
  • The effect of sub-grid turbulence and combustion models on the mean flame height in a heptane pool fire according to the Fire Dynamics Simulator (FDS) version (5 and 6) based on Large Eddy Simulation (LES) was examined. The heat release rate for the fire simulation was provided through experiments performed under identical conditions and the predictive performance of the mean flame height according to FDS version was evaluated by a comparison with the existing correlation. As a result, the Smagorinsky and Deardorff turbulence models applied to FDS 5 and 6, respectively, had no significant effects on the mean flow field, flame shape and flame height. On the other hand, the difference in pool fire characteristics including the mean flame height was due mainly to the difference in the mixture fraction and Eddy Dissipation Concept (EDC) combustion models applied to FDS 5 and 6, respectively. Finally, compared to FDS 6, FDS 5 provided the predictive result of a significantly longer flame height and more consistent mean flame height than the existing correlation.

Development Plan for the Consequence Management in Response to Large-Scale Wildfire Disasters Using Air Force Transport Aircraft (C-130) (공군 수송기(C-130)를 활용한 대형산불 재난 대응 시 사후관리(CM) 발전방안)

  • Sangduk Kim;Minki Kim
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.232-243
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    • 2024
  • Purpose: Recently, large-scale forest fires caused by climate change, natural disasters, and human factors have been increasing every year in the East Coast and Taebaek Mountains region. Although forest fire extinguishing using helicopters is currently increasing, the need to introduce air force transport aircraft has continued to be raised due to the importance of early fire extinguishment to respond to large forest fires and the difficulty of extinguishing forest fires between sheep. This study seeks to present a plan for developing a post-fire management system for several aspects - achieving operational objectives, overcoming the operating environment, selecting a staging area, and efficient operation measures - to efficiently perform forest fire extinguishing missions using Air Force transport aircraft. Method: Based on literature research on forest fire extinguishing, forest fire extinguishing experiments using fixed-wing aircraft, and the operation status and operation method of forest fire extinguishing helicopters, the pros and cons of helicopter operation and the effects of large forest fire extinguishing using a large transport aircraft (C-130) Analyze the effectiveness of operation through analysis. Results: When extinguishing a large forest fire, an effective CM (Consequence Management) application plan was derived, including effective operation, control, command system, dispatch request, and forest fire extinguishment when integrating helicopter and fixed-wing aircraft (C-130). Conclusion: The application of the concept of CM (Consequence Management) is partially applied to some areas of chemical, biological, and radiological (CBRNE) protection in Korea, but efficient operation, control, and command systems are established when integrated operation of helicopters and large aircraft (C-130) in forest fire extinguishment. the concept of CM (Consequence Management), which is operated in advanced countries, was applied for safety management, dispatch requests, and forest fire extinguishing, thereby contributing to the establishment of a more advanced disaster and post-disaster management system.

Practical Predictive Formulas for Residual Strengths of Fire-Damaged Normal Strength Reinforced Concrete Square Columns (화해를 입은 보통강도 철근콘크리트 정방형 기둥의 실용 잔존내력식)

  • Lee, Cha-Don;Lee, Seung-Whan;Lee, Chang-Eun
    • Journal of the Korea Concrete Institute
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    • v.18 no.1 s.91
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    • pp.3-12
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    • 2006
  • The behavior of concrete structures subject to fire is complex, depending on many factors. The factors usually considered in research include the level and endurance of temperatures in concrete and reinforcing bars, the mechanical properties of the steel and concrete, moisture contents, cover thickness, existence of eccentricity, and member geometry among others. Although there are a few sophisticated numerical models which can trace the effects of these important parameters on the residual capacity of reinforced concrete columns damaged by fire, practical predictive formulas are in need for rapid yet reasonable assessment in practice. The practical formulas are developed in this study for fire-damaged normal strength reinforced concrete square columns, which can approximate the predictions of those sophisticated numerical models with ease in use. The formulas take into account the effects of exposure time to fire, concrete strength, reinforcement ratio and sectional area. The developed formulas are seen to correlate with the predictions of numerical model in a reasonable agreement. Some examples are also presented in determining the residual strength, safety and additionally needed strengths for a fire-damaged reinforced concrete column.

The Effects of Apartment Inhabitants' Life Management and Administrative Management on Housing Satisfaction (아파트 거주자의 생활 및 운영관리가 주거만족도에 미치는 영향)

  • Kim, Myung-Hee;Kong, Ha-Sung
    • Journal of the Korea Safety Management & Science
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    • v.22 no.3
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    • pp.53-60
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    • 2020
  • This study aims to find the causal relationship between the effects of apartment inhabitants' life management and administrative management on housing satisfaction. The study results are as follows. Firstly, life management showed to have a positive effect on life satisfaction. In other words, the better the management of public order and facilities, the higher the satisfaction of housing satisfaction. Thus, the principal agent of management needs to increase inhabitants' housing satisfaction through education and training on developing life management techniques. Secondly, administrative management showed to have a positive effect on life satisfaction. Thus, the more accurate the completion documents and management transfer process necessary for administrative management, the higher the cost-cutting effects of accounting, construction, and service contracts, the more transparent the resident agreement process in accordance with management policies, the more transparent the election process of building representatives and resident representatives, and the higher the effects of energy saving, the higher the housing satisfaction of inhabitants. This revealed that the principal agent of management needs to increase housing satisfaction through education and training on developing administrative management techniques because the level of administrative management had a positive effect on housing satisfaction. As a result, in order to create reliability between inhabitants and the principal agents of management, the transparency of administrative management such as document disclosure must be ensured, thus improving the housing satisfaction of inhabitants.

3D Graphics Library for Generating Real-time Special Effects

  • Kim Eung-Kon;Yoo Bong-Kil;Song Seung-Heon
    • Journal of information and communication convergence engineering
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    • v.2 no.3
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    • pp.172-176
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    • 2004
  • In special effects industry there is a high demand to convincingly mimic the appearance and behavior of natural phenomena such as smoke, waterfall, rain, and fire. Particle systems are methods adequate for modeling fuzzy objects of natural phenomena. This paper presents particle system graphics library for generating special effects in video games and virtual reality applications. The library is a set of functions that allow c++ programs to simulate the dynamics of particles for special effects in interactive and non-interactive graphics applications, not for scientific simulation.

Drag Reduction of Pipe Wall For Fluid Flow due to Injected Polymer Solution - II. Local Drag Reduction in Turbulent Flow- (고분자용액에 의한 유체수송관벽의 저항감소 -II. 난류흐름에서 국소저항감소-)

  • 추낙준;유경옥
    • Fire Science and Engineering
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    • v.5 no.2
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    • pp.11-20
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    • 1991
  • Dilute polymer solutions were injected into turbulent pipe flow of a Newtonian fluid. The local drag reduction for injection of polymer solution at the pipe wall was larger than that at centerline. From the above result we may conclude that the polymer additives were found to influence the flow in the neighborhood of the wall. The effects of the injection apparatus on the local drag reduction are small compared to the drag-reducing effects. The extent of drag reduction increased with polymer concentration and injection flow rate, and the maximum drag reduction obtained were 47% for Polyox Coagulant and 35% for Separan AP-273. In respect to polymer degradation, the polyacrylamide showed better shear stability than the polyethyleneoxide and thus the former expected to have a sharper molecular weight distribution.

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The Influence on the Stack effect that Pressure differential system to smoke control in High-rise buildings (초고층 건축물에서 급기가압제연이 연돌효과에 미치는 영향)

  • Lim, Chae-Hyun;Park, Yong-Hwan
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.235-238
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    • 2008
  • High-rise buildings with stack effect caused by the foreclosure, which significantly delayed the spread of a fire in effects of these stack effect driving force said. In this research on the stack effect of the lobby if the pressurization of the stairwell analysis of the pressure distribution of the CONTAMW. Overall, the pressurization of the lobby makes it stairwell amount of pressure(+) to the zone in pressure designed to prevent the spread of smoke control performance and found that, the way a normal state and sub-pressurization in the stairwell with stack effect of the turbulence Such as the formation of the upper flow, but, in the upper atmosphere with pressurization was formed by the underlying trend.

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Study of the Perfomance Estimation for (Semi)Incombustible Composite ((준)불연성 복합재료의 성능 평가 연구)

  • 조정미;장기욱;김규직
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.97-101
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    • 2001
  • Composite materials have been applied widely in interior panels of buildings and transport vehicles. Recently good fire performance and weight reduction are key issues in the fields. In the present study we investigated effects of processing parameters on the performance of honeycomb sandwich panels, especially peel strength of the panel and fire performance. The processing parameters considered were types of matrix resin, resin contents, panel cure conditions, and surface painting process conditions. The results showed that the higher resin content provides the better peel strength. Controled cure steps are also needed to obtain good pee] strength. Paint processing parameters including base putty thickness and paint drying conditions and paint thickness are important to obtain good paint adhesion and good fire performance.

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A study on correlation between empowering leadership, growth needs and turnover intentions in 119 emergency medical technicians (구급대원의 임파워링 리더십과 성장욕구 및 이직의도와의 상관관계에 관한 연구)

  • Yang, Hyun-Mo;Jeon, Hyuk-Jin;Gang, Bo-Ra
    • The Korean Journal of Emergency Medical Services
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    • v.17 no.3
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    • pp.29-37
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    • 2013
  • Purpose: The purpose of this study is to investigate how empowering leadership effects on growth needs and turnover intentions to emergency medical technicians. Methods: The study was based on seventy six paramedics and seventy EMTs-basic who were working at the fire stations. A survey questionnaire was used to prove connection between empowering leadership, growth needs, and turnover intentions. Results: There was a positive correlation between empowering leadership and growth needs, and negative correlation between empowering leadership and turnover intentions. There was a positive correlation between emergency medical technicians growth needs and turnover intentions. Conclusion: This analysis is empirically applied to study the empowering leadership focused on the empowerment act of leader to a leading role to empowerment in fire service organization.