• Journal of the korean Society of Automotive Engineers
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• v.10 no.6
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• pp.61-71
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• 1988

본 논문에서는 Laser Rayleigh Pyrometer에 의한 광학계의 개조와 측정기술을 발전시켜 지금까지의 측정이 불가능한 밀폐용기내에서 분출화염의 온도측정을 시도하여 분출화염에 의한 착화나 소염의 연구에 중요한 자료를 얻고자 하는데 있다. 밀폐용기내에서의 온도측정은 대기개방형에서와 같이 Laser의 에너지를 증대시키기 위해 이용한는 다중반사 Mirror가 사용될 수 없을 뿐만 아니라 약한 Rayleigh산란빛에 의하여 입사창이란 Laser Trap으로 발생하는 강한 배경광 및 분출화염 뿐만 아니고 착화된 화염에서 대량의 화학발광은 피할 수 없다. 본 논문은 이와 같은 영향을 제거하는데 노력하여 밀폐용기내의 연소장에서 온도를 측정하였으며 또 측정가능성을 시사하였다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.319-323
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• 2010

건축물의 창문 등에서 분출하는 화염 특성은 건축물의 화재안전성을 확보하는데 중요한 과제이다. 본 연구에서는 분출화염의 특성을 파악하여 건축물의 화재안전설계에 활용하기 위해 축소모형을 이용하여 화재실험을 실행하였다. 실험에서는 소규모 모형을 제작하고 가스버너를 화원으로 하여 개구부와 화원의 크기에 따른 분출열기류의 온도분포성상을 파악하였다.

• Clean Technology
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• v.13 no.4
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• pp.300-307
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• 2007

The combustion characteristics of diffusion flame formed in the wake of a cylindrical stabilizer with varying fuel injection angle were studied. This study was performed by measuring the flame stability limits, lengths and temperatures of recirculation zones of flames, turbulence intensity in the wake of stabilizer, and concentration distribution of combustion gas, and by taking photographs of flames. The flame stability limits are dependent on fuel injection angle and main air velocity. The length and temperature of recirculation zone are dependent on fuel injection angle. As the length of the recirculation zone is decreased, the flame shows more stable behavior. The temperature of recirculation zone has a maximum value at the condition of theoretical mixture. The flame stability is enhanced when the temperature in the recirculation zone decreases. The turbulence intensity in the wake of stabilizer is independent of the fuel injection angle, but it is affected by stabilizer itself and main air flow condition. If the stabilization characteristics of flame is good, the concentration of $C_3H_8$ is high, but the concentration of $CO_2$ is low at the boundary of recirculation zone. The combustion characteristics of diffusion flame can be controlled by changing the fuel injection angles. The appropriate fuel injection angle should be selected to get high combustion efficiency, high load power, low environmental pollution, and clean combustion condition of fuel.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.37-38
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• 2017

This study identified the effects of flame on the upper by fire plume ejected. we implemented model experiment according to investigation of housing area effect, window aspect ratio and balcony availability. we confirmed that opening ratio was increased according to housing area larger. the square window confirmed that is progressing fire plume ejected of free space. According to the value of an opening aspect ratio 'n' getting higher, the horizontal widow is getting that increased the risk as the fire spread an external to the top of opening. it is determined to the fundamental solution about fire safety in the extended balcony of apartment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.219-220
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• 2016

The behavior of fire plumes has not yet been clearly identified for cases where sidewalls are installed near an opening in an unconfined space. In this research, we aim to quantitatively identify the effects on fire spread when sidewalls are located on both sides of an opening. Specifically, we focus on the effects on the fire plume of the relation between the location of sidewalls and the opening, and carry out a scale-model experiment to devise a flame height model and to evaluate the temperature distribution along the central axis of the flame.

• Journal of Energy Engineering
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• v.10 no.3
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• pp.223-232
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• 2001

To study the stabilization characteristics of diffusion flame formed in the wake of a cylindrical bluff body with fuel injection, the flame stability limits, length and temperature of recirculation zone of flame, turbulence intensity distribution near the recirculation zone of flame were measured and analyzed. The length of recirculation zone is independent on main fuel injection quantity, but it is dependent on fuel injection angles, air stream velocity, and auxiliary fuel injection into recirculation zone. For diffusion flame, in general, the flame stabilization is deteriorated with increase of he length of recirculation zone, but if the turbulence generator is installed, the flame stabilization is improved with increase of the length of recirculation zone. The temperature of recirculation zone is dependent on fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators, and it dependent on fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators, and it has a maximum value at the condition of each theoretical mixture. In general, the more temperature of recirculation zone is low, the more flame is stable. But when the turbulence generator is installed, the more temperature of recirculation zone is low, the more flame is unstable. The turbulence intensity in the wake of bluff body is increased with increase of diameter or blockage ratio of grid. The more turbulence intensity is increased by installation of turbulence generator, the more flame is unstable. Finally, It is clear that the stabilization characteristics of diffuser flame can be controlled by some parameters such as fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.12
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• pp.3344-3351
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• 1995

The stability of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated in various fuel injection angles, fuel injection ratios, grids and extension ducts. The flame stability limits, temperature distributions and length of recirculation zones, direct photographs of flames were measured in order to discuss the stabilization mechanism of the diffusion flame. The results from this study are as follows. The fuel injection angle is an important factor in determining the flame stability. Stability limits can be improved by variety of the fuel injection ratio. When the grid and extension duct are set, stability characteristics are varied with the blockage ratios, grid intervals, and grid numbers. The recirculation zone not only serves as a steady ignition source of combustion stream but also governs the stabilization mechanism.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.67-72
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• 2011

본 연구는 건축물 화재성상 시뮬레이션 개발을 위한 기초 연구 자료로서 건축물 화재시 높은 비중의 가연물과 좁은 이격거리로 인하여 화재 발생시 급격히 연소확대될 위험성이 높고, 개구분출화염이 건물 화재확산의 중요한 요인이나 이 분야에 대한 연구는 부족한 실정이며, 또한 화재성상 예측시 기존 시뮬레이션에서 화재확산의 중요한 인자인 바람의 요소가 고려되지 않았다. 이에 대하여 개구분출 실물화재실험을 통하여 유풍시 개구분출화염에 기인한 수식을 도출하였으며, 이를 기반으로 향후 기존의 바람 인자를 고려하지 않은 화재성상 예측 시뮬레이션에 적용 가능성을 모색하여 국내 실정에 맞는 화재 성상 시뮬레이션 개발 구축에 대한 기초자료로 제시한다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.250-258
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• 2010

A numerical analysis of reactive flow in a liftoff flame is accomplished to elucidate the characteristics of flame propagation velocity and volume integral of reaction rate with the variation of nozzle diameter and fuel injection flow rate in a liftoff flame consisted with fuel rich region, fuel lean region and diffusion flame region. The increase of fuel injection velocity enhances flame propagation velocity for the selected three nozzle diameter(d=0.25, 0.30, 0.35mm), but its effect on the flame propagation velocity is not much greater than 4.3%. The increase of fuel flow rate is directly and linearly related with the volume reaction rate and so the volume reaction rate, not the flame propagation velocity, might be considered to accommodate the variation of fuel flow rate in a liftoff flame.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.4
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• pp.912-919
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• 1990

본 연구에서는 다중선회연소기의 원리에 기초하여 속도차가 있는 두 공기류의 전단층에 기체연료를 분출하여 연소시키면 연료가 두 공기류 사이에 유입되므로 연료 가 산화제의 접촉면적이 증대되고 또한 난류혼합속도가 큰 영역으로 연료가 유입되므 로 혼합효과가 증대되어 고부하연소에 적절한 방식이 될 것으로 생각하여 동축이중공 기분류중의 난류 확산화염에 대해 그 화염구조를 밝히고 이 화염을 실용연소기에 응용 하기 위한 기초자료를 얻는데 목적이 있다.