• Title/Summary/Keyword: Stationary Fire

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Numerical Simulations of the Supersonic Jet Impingement in a Confined Plenum of Vertical Launching System

  • Lee Kwang-Seop;Lee Jin-Gyu;Hong Seung-Kyu;Ahan Chang-Soo
    • 한국전산유체공학회:학술대회논문집
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    • 2006.05a
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    • pp.301-305
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    • 2006
  • The Vertical Launching System design is especially complicated by complex flow structure in a plenum with the severe thermal state and high pressure load form the hot exhaust plume. The flow structures are numerically simulated by using the commercial code, CFD-FASTRAN with the axi-symmetrical Navier-Stokes equations. Two different cases are considered; that is, the stationary fire and the moving fire.

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A Study on the Performance Characteristic of a Fire Pump with Various Operating Conditions (운전조건 변화에 따른 소방펌프 성능특성 연구)

  • Park, Sung-Kyu;Noh, Go-Sub;Kim, Yun-Je
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2011-2016
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    • 2004
  • In order to develop a high efficiency fire pump, its performance characteristics with various operating conditions are investigated. The governing equations are derived from making using of three-dimensional Navier-Stokes equations with the standard ${\kappa}-{\varepsilon}$ turbulence model and SIMPLE algorithm. Using a commercial code, CFX, pressure distribution and flow fields in a fire pump are calculated with various ranges of rotating speed 800-2400 rpm. Particularly, calculations with multiple frames of reference method between the rotating and stationary parts of the domain are carried out. With the help of numerical results, correlation formula between the casing pressure and the efficiency is derived.

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PM Management Methods Considering Condensable PM Emissions from Stationary Sources in Seoul and Incheon (고정오염원의 응축성 먼지 배출량을 고려한 서울과 인천의 먼지 관리방안)

  • Lee, Im Hack;Choi, Doo Sung;Ko, Myeong Jin;Park, Young-Kwon
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.4
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    • pp.319-325
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    • 2017
  • In this study, the new particulate matter emissions considering condensable PM (CPM) of stationary pollutant sources were calculated to modify the CAPSS emissions based on only filterable PMs in Seoul and Incheon. When the new calculated emissions were compared to the existing filterable PM based emissions of local governments, different contribution patterns of emission sources were found. For example, the proportion of mobile sources was high when the filterable PM was considered; however, the contribution of non-industrial sources was dominant in Seoul when the emissions of CPM were considered. Also, the proportion of energy industrial combustion and manufacturing combustion sources was significant in Incheon when CPM emissions considered. Therefore, it seems to be much desirable to consider CPM emissions for determining adequate locations of collective energy facilities and manufacturing combustion facilities in the future. In addition, CPM should be considered to solve the dust problem nationwide. The emission analysis, diagnosis, prediction and countermeasures using CPM emissions should be appropriately performed.

Analysis of Changes in NDVI Annual Cycle Models Caused by Forest Fire in Yangyang-gun, Gangwon-do Using Time Series of Landsat Images

  • Choi, Yoon Jo;Cho, Han Jin;Hong, Seung Hwan;Lee, Su Jin;Sohn, Hong Gyoo
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.4
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    • pp.3-11
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    • 2016
  • Sixty four percent of Korean territory consists of forest which is fragile for forest fire. However, it is difficult to detect the disaster-induced damages due to topographic complexity in mountainous areas and harsh weather conditions. For this reason, satellite imaging systems have been widely utilized to detect the damage caused by forest fire. In particular, ground vegetation condition can be estimated from multi-spectral satellite images and change detection technique has been used to detect forest fire damages. However, since Korea has clear four seasons, simple change detection technique has limitation. In this regard, this study applied the NDVI(normalized difference vegetation index) annual cycle modeling technique on time-series of Landsat images from 1991 to 2007 to analyze influence of forest fire of Yangyang-gun, Gangwon-do in 2005 on vegetation condition. The encouraging result was obtained when comparing the areas where forest fire occurs with non-damaged areas. The mean value of NDVI was decreased by 0.07 before and after the forest fire. On the other hand, annual variability of NDVI had been increasing and peak value of NDVI was stationary after the forest fire. It is interpreted that understory vegetation was seriously damaged from the forest fire occurred in 2005.

A Study on Fire Analysis According to Temperature Characteristics of an Incandescent Electric Lamp at 220V/100W (220V/100W 백열전구의 온도특성에 따른 화재분석에 관한 연구)

  • Shong, Kil-Mok;Han, Woon-Ki;Kim, Young-Seok;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.20 no.1 s.61
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    • pp.43-49
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    • 2006
  • In this paper, we are studied on the temperature characteristics and fire progress of an incandescent electric lamp at 220V/100W. In the case of stationary state, the ignition possibility of the incandescent electric lamp due to the heat generation was low because the temperature was measured at $161.9^{\circ}C$ the temperature was increased at $538.1^{\circ}C$ in the airtight chamber, but it does not generated the fire because the oxygen was not exist in the airtight chamber. When the lamp is broken, the filament of lamp was melted in the air. The gas of lamp interior spurted to the weakest part by external flame. Thus, the incandescent electric lamp is high possibility of fire when oxygens from airtight space. Also, it is known that the possibility of ignition is very high if combustion materials(sawdust) exists on surrounding. These experimental results will be utilized for the data in the investigation electrical fire cause.

Development of Fire Detection Algorithm for Video Incident Detection System of Double Deck Tunnel (복층터널 영상유고감지시스템의 화재 감지 알고리즘 개발)

  • Kim, Tae-Bok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.9
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    • pp.1082-1087
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    • 2019
  • Video Incident Detection System is a detection system for the purpose of detection of an emergency in an unexpected situation such as a pedestrian in a tunnel, a falling object, a stationary vehicle, a reverse run, and a fire(smoke and flame). In recent years, the importance of the city center has been emphasized by the construction of underpasses in great depth underground space. Therefore, in order to apply Video Incident Detection System to a Double Deck Tunnel, it was developed to reflect the design characteristics of the Double Deck Tunnel. and In this paper especially, the fire detection technology, which is not it is difficult to apply to the Double Deck Tunnel environment because it is not supported on existing Video Incident Detection System or has a fail detect, we propose fire detection using color image analysis, silhouette spread, and statistical properties, It is verified through a real fire test in a double deck tunnel test bed environment.

Diffusion and Disperision of Injected $CO_2$Gas Into the $N_2$Gas Flow ($N_2$기체의 흐름에 주입된 $CO_2$기체의 확산 및 분산)

  • 김유식;안대영
    • Fire Science and Engineering
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    • v.16 no.3
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    • pp.1-7
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    • 2002
  • Diffusion and dispersion of injected $CO_2$gas into the $N_2$ gas flow are complex. In the packed column with porous particles the axial dispersion and the extra-particle mass transport as well as the intra-particle mass transport are involved. The pulse spreads by stationary diffusion during the period of arrested flow. Hence, the effect of axial dispersion, and of entrance and exit, as well as that of intraparticle convection should be eliminated during the period. The effective diffusivity was determined experimentally by using the gas chromatography, which is to arrest the gas flow during the period after injecting the pulse. This experiment method hasn't been used often in the field. Effective diffusivities are raised with temperature increasing, and it is quite satisfied com-pared to literature values. In this study, the calculated data of gaseous chemical for extinguish fires could be helpful to appreciate several physical phenomenons. Also, it could be expected that, the calculated data of this study might be very useful for development of excellent gaseous chemical for extinguish fires and improvement of its efficiency.

A Study of An Initial Alignment Method of Underwater Vehicle Dropped from Aircraft (항공기에서 투하되는 수중운동체의 초기정렬기법 연구)

  • 류동기;김삼수
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.1
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    • pp.21-29
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    • 2003
  • The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.

Analysis of Fire Damaged Concrete Ca(OH)2 by Heating Temperature Using Scanning Electron Microscope and X-ray Diffraction (SEM과 XRD를 이용한 수열온도별 화재피해 콘크리트의 Ca(OH)2 분석)

  • Lim, Gun-Su;Han, Soo-Hwan;Hyun, Seung-Yong;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.149-150
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    • 2022
  • In Korea, there is no clearly established technology for diagnosing and evaluating the damage depth of concrete structures created by fire. There have been cases of repairing, reinforcing, and demolishing degraded structures without diagnosing the damage depth. The commonly used phenolphthalein-based carbonate thickness measurement does not satisfy the complete disappearance condition of Ca(OH)2 in the interval where the relatively stationary flow declines after exposure to high temperatures. Even a small amount of Portlandite[Ca(OH)2] reacts with a red color, and the damage depth is misjudged. It was confirmed by X-ray diffraction and scanning electron microscope that Ca(OH)2 existed from 300℃ to 500℃ where the residual compressive strength decreased.

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Analysis of the Push-Pull Queueing System under the N-Policy (N-정책을 갖는 Push-Pull 대기행렬 시스템의 분석)

  • Kim, Soo Yeon;Kim, Nam Ki;Kim, Jin Dong;Lee, Sang Min;Chae, Kyung Chul
    • Journal of Korean Institute of Industrial Engineers
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    • v.31 no.4
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    • pp.297-302
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    • 2005
  • Kopzon and Weiss adopted the notion of push-pull into the queueing system recently. We extend this queueing system to the ($N_1,N_2$)-policy version such that the original system corresponds to the special case $N_1=N_2=1$. For the extended system, we perform the cycle analysis and obtain the PGF of the stationary number of customers in the system.