• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.486-491
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• 2008

The spray characteristics and drop size measurements have been experimentally studied in liquid jets injected into subsonic crossflow. With water as fuel injection velocity, injection angle and atomizer internal flows were varied to provide of jet operation conditions. The injector internal flow was classified as three modes such as a non-cavitation flow, cavitation, and hydraulic flip flows. Pulsed Shadowgraph Photography measurement was used to determine the spatial distribution of the spray droplet diameter in a subsonic crossflow of air. And this study also obtains the SMD(Sauter Mean Diameters) distribution by using PLLIF(Planar Liquid Laser Induced Fluorescence) technique. The objectives of this research are getting a droplet distribution and drop size measurement of each condition and compare with the other flows effect. As the result, This research have been showed the droplet size were spatially dependent on air-stream velocity, fuel injection velocity, injection angle effects and normalized distance from the injector exit length.(x/d, y/d)There are also different droplet size characteristics between cavitation, hydraulic flip and the non-cavitation flows.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.909-914
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• 2001

Fluid properties which are most commonly used to evaluate spray atomization characteristics, are important because they affect velocity and size distribution of droplets. The purpose of this study was to incorporate the significant characteristics in atomization process of industrial etching spray and how each of them affects the design of precise pressure-swirl nozzles. The experiment was carried out with different viscosity and density of fluid. The macro characteristics of liquid spray, such as the spray angle and shape were captured by PMAS and the micro characteristics of liquid spray, such as droplet size and velocity were obtained by PDA. The mean velocity and SMD of droplets were measured along axial and radial direction. It was found that the higher viscosity and density resulted in the larger SMD and the lower mean velocity of droplets.

• 대한기계학회논문집
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• 제15권6호
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• pp.2147-2159
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• 1991

본 연구에서는 가장 다순한 내부혼합형 이류체분사노즐의 기류속도, 액체유량, 노즐직경 및 혼합길이, 기액접촉각을 변화시켜 평균입경(SMD), 분무각, 입도분포, 분 무분사량분포 등을 조사하여 노즐형상에 따른 분무특성의 변화를 자세히 밝혀, 분무특 성을 조절할 수 있는 이류체분사 노즐의 설계에 대한 기초적 자료를 제시하고자 한다.

• 한국분무공학회지
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• 제1권2호
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• pp.42-49
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• 1996

The structure of sprays from a simplex type pilot nozzle atomizer is studied experimentally by measuring velocities, Sauter mean diameter, and number density. Interaction of the spray with gas-phase flow field generated from a 1 MW range industrial gas turbine combustor adopt ing a counter-swirler is investigated. Various spray behaviors are reported. Especially interest ing characteristics are the tangential motion of the spray and of the spray with swirl interaction. It shows a Rankine combined vortex type of velocity characteristics, having linear velocity profile inside the inner core whole small particles exist and rapidly decreasing velocity profiles outside. Interacting spray has relatively uniform number density profiles compared to the nozzle spray itself.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.80-86
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• 1997

This experiment was undertaken to investigate spray characteristics of the conventional injection system and the ultrasonic energy added injection system. Sauter mean diameter was measured under the variation of injection pressure and the spray distance. To measure the droplet size, we used the Malvern system 2600C. The spray angle and mass distribution were analyzed to the CCD camera and the patternater. After experiment, it was found that the ultrasonic energy added injection system had smaller Sauter mean diameter of droplet, wider mass distribution and wider spray angle than the conventional injection system had.

• 대한기계학회논문집
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• 제16권5호
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• pp.933-942
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• 1992

본 연구에서는 이상류 동축 노즐의 미립화 기구를 규명하기 위한 기초단계로 20˚의 증류수를 사용하여 이상류 동축노즐의 평균액적 직경에 미치는 공급유량의 영 향을 직접사진 촬영법을 사용하여 규명하고자 한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.1-5
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• 2008

An experimental study was performed to develop the rotational fuel injection system of the micro turbojet engine. In this system, fuel is sprayed by centrifugal forces of engine shaft. The test rig was designed and manufactured to get droplet information on combustion space. This experimental apparatus consist of a high speed rotational device(Air-Spindle), fuel feeder, rotational fuel injector and acrylic case. To understand spray characteristics, spray droplet size, velocity and distribution were measured by PDPA (Phase Doppler Particle Analyzer) and spray was visualized by using Nd-Yag laser-based flash photography. From the test results, the length of liquid column from injection orifice is controlled by the rotational speeds and Sauter Mean Diameter(SMD) is decreased with rotational speed. Also, Sauter Mean Diameter is increased as increasing mass flow rate at same rotational speeds.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.52-58
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• 1998

The spray characteristics of air-assisted fuel injection and its effects on the engine combustion was investigated in this study. The atomization characteristics of a Bosch fuel injector inserted into the air-assist adapter were measured using particle motion analysis system. Droplet size decreased with air supplied and fine spray with below $60\mu\textrm{m}$ of SMD was acquired under the conditions of air-assist pressure over 0.5bar. The lean combustion performance of a 1.8L DOHC engine equipped with air-assist adapters was tested on the dynamometer. When the assistant air pressure is 1.0bar, lean limit recorded the highest value, and CO, HC emissions were decreased at the pressure over 1.0bar.

• 한국분무공학회지
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• 제3권4호
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• pp.16-24
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• 1998

The fuel injection type, in the gasoline engines of atomization of fuel droplet and its distribution hae influenced directly on the decision of engine performance and harmful emission. In this paper, atomization characteristics of fuel spray is investigated with microscopic visualization system. Particle motion analysis system is used to measure the SMD from fuel spray of air-assisted injector by initial factors such as temperature of ambient air and air-assisted pressure. As air-assist pressure and ambientair temperature increase, the SMD is decreased, and its variation is more stable.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.171-174
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• 2008

소형 회전연료 분사장치의 분열과정 특성을 연구하기 위한 실험적 연구를 수행하였다. 이러한 분열과정의 특성을 이해하기 위해 PDPA(Phase Doppler Particle Analyzer)시스템을 사용하여 분무입자의 크기와 속도를 측정하였다. 또한 Nd-Yag Laser를 광원으로 사용하여 분무를 가시화하였다. 실험결과 Injection Orifice로부터 생성된 액주는 회전수에 의해 지배되고, SMD(Sauter Mean Diameter)와 분무특성은 Injection Orifice의 직경에 큰 영향을 받는다는 것을 알 수 있었다.