• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.230-233
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• 2008

본 연구는 수분무 소화설비의 효용성에 대한 기초평가를 수행할 목적으로 FDS 수치시뮬레이션을 수행하였다. 화재강도 및 풍속의 변화에 따른 화재시 온도 및 연기농도에 대한 안전성 확보 효과를 분석하였다. 터널내 풍속이 없는 경우 수분무는 냉각효과에 의한 온도 및 연기농도 감소효과가 아주 우수하여 대피자의 안전성 확보에 효과적이었다.

• 설비공학논문집
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• 제15권7호
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• pp.572-578
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• 2003

The present study was numerically and experimentally performed to investigate the fire suppression performance of water mist spray subjected to thermal radiation in closed space. Downward-directed water mist sprays to interact with an under kerosine pool fire were investigated in test facility The mass mean diameters of water mist droplet were measured by PMAS under various flow conditions. The developed water mist spray nozzle was satisfied to the criteria of NFPA 750, Class 1. The mechanism of the fire suppression by water mist was attributed to the cooling of the fire surface which lead to suppressed of fuel evaporation. It was proved that the water mist spray system under lower pressures could be applied to underground fire protection system.

• International Journal of Automotive Technology
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• 제7권4호
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• pp.493-500
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• 2006

Investigation on the fuel adhering on a wall was carried out experimentally to clarify the characteristics of impinging diesel sprays. Diesel sprays were injected into a high-pressure chamber of cold state and impinged to a wall having various impingement distances and ambient pressures. Photographs of both the fuel film and the post-impingement spray were taken through a transparent wall. Adhered fuel mass on a wall was measured by means of dividing into two types of fuel state: the fuel film itself; and sparsely adhered fuel droplets. Adhering fuel ratio was predicted and further the distribution of fuel mass for impinging diesel spray was analyzed as a function of time. As result, with an increase of the ambient pressure, both the maximum fuel film diameter and the adhered fuel ratio decreased. Based on some assumptions, the adhering fuel mass increased rapidly until the fuel film diameter approached the maximum value, and then increased comparatively gradually.

• 한국분무공학회지
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• 제1권2호
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• pp.33-41
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• 1996

Mixture formation is one of the important factors to improve combustion performance of MPI gasoline engines. This is affected by spray and atomization characteristics of injector. Especially, in the case of EGI system, air-fuel mixing period is too short and formed a lot of fuel-film in the intake manifold and cylinder wall. This fuel-film is not burnt in cylinder, it is exhausted in the form of HC emission. In this paper, spray characteristics such as size distributions, SMD, and spray angle are measured by PMAS, and the fuel-film measuring device is developed specially. Using this device, the amount and distribution of fuel-film which flows into through valve can be measured Quantitatively. As the result of these experiments, the information of optimal spray characteristics and injection condition that minimize the fuel-film can be built up.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.466-474
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• 2004

The characteristics of liquefied butane spray are expected to be different from conventional diesel fuel spray, because a flash boiling spray is expected when the surround pressure is below the saturated vapor pressure of the butane(0.23MPa 98K). The axial velocities. radial velocities. and size distributions in butane sprays were measured with PDPA(Phase Doppler Particle Analyzer) system. Sprays were macroscopically observed by using the high speed camera in case that the surround pressure is 0.37MPa and 0.15MPa. respectively. Compared with the conventional spray. the reversed results were investigated when the surround pressure is below the saturated vapor pressure of the butane.

• 대한기계학회논문집
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• 제6권3호
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• pp.256-260
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• 1982

This paper presents the characteristics of fuel spray in a diesel engine. In this paper, in order to obtain spray droplet size in a diesel engine, water was injected into the cylinder at room temperature and pressure by injection system. Spray droplet size was measured by liquid immersion technique with a lubricant used as an immersion liquid for spray water from injection nozzle. In this experiment, single hole type throttle nozzle are used at same operating conditions, which included opening pressure of nozzle, fuel delivery, and injection speed. Sauter mean diameter decrease with the increase of injection pressure and decrease in injection nozzle diameter. The rate of spray penetration increased with increasing injection pressure and diameter of injection nozzle at the constant spray conditions.

• 한국분무공학회지
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• 제14권3호
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• pp.117-121
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• 2009

Biodiesel fuel has different spray patterns, because viscosity and surface tension of biodiesel fuel are higher than that of diesel fuel. The diesel combustion is strongly controlled by the fuel spray behavior in combustion chamber. So, it was needed to understand the spay characteristics of non-esterification biodiesel fuel. In this study, the spray characteristics of non-esterification biodiesel fuel was investigated to confirm of an effect of WDP. The characteristics of fuel atomization was analyzed with SMD and span factor through laser diffraction particle analyzer (LDPA), and the process of spray injection was visualized through the visualization system composed of a halogen lamp and high speed camera. It was found that injection delay time and SMD of blended fuel with WDP get shoter and smaller than that of non-esterification biodiesel fuel.

• 한국자동차공학회논문집
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• 제2권4호
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• pp.39-49
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• 1994

An experimental investigation was undertaken in a diesel spray to evaluate wall impingement behavior and droplet size distribution. Emphasis is placed on the possibility of the application for new combustion type which is based on OSKA-D type. Visualization were employed using optical scheme which was a spark shadowgraphy to observe the behavior of wall impingement caused by diesel spray vertically injected at the center of the combustion chamber. Droplet size measurements using Malvern system were made to quantify the visual observations with surface diameter of impingement. The effects of the surface dia. variation on the droplet size during injection with the wall impingement spray are discussed. It was found that for the wall impingement spray the droplet size becomes greatly small rather than the spray without the wall impingement and the droplet deposition rate of the injection fuel is decreased as the surface area of impingement becomes small.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.95-105
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• 1997

A diesel engine has become smaller and higher, thus sprays injected in high speed may be impinged on a small combustion chamber wall if there is not enough strong swirl. Those combustion chambers should have proper measures to avoid the spray impinged and deposited on a wall. One of the measures is a chamber prepared impingement parts raised on a chamber wall surface. In this system a spray is injected into the raised pip, broken into a number of smaller drops and spreaded out away from the wall surface. Therefore the fuel droplets distributes over inside of the combustion chamber. In this study, the positions, sizes and angles of the raised land are discussed to help the chamber design using spray wall impaction. The characteristics of the spray impinged on various lands are investigated and compared with each other. Then chamber shapes are discussed with the spray characteristics and the proper positions and size are proposed in some chamber volumes.

• 한국분무공학회지
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• 제7권3호
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• pp.1-6
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• 2002

In this study numerical and experimental study on the spray atomization characteristics of a GDI injector is performed. To carry out numerical analysis, four hybrid models that are composed of conical sheet disintegration model, LISA model, DDB model, and RT model are used. The experimental results to evaluate the prediction accuracy of hybrid models are obtained by using phase Doppler particle analyzer and spray visualization system. It is shown that the prediction accuracy of hybrid model concerning spray developing process and spray tip penetration is good for all hybrid models, but the hybrid breakup models show different prediction of accuracy in the case of local radial SMD distribution.