• Title/Summary/Keyword: 이중 분무

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A Effect of Fuel Properties on Spray Structure for Dual Orifice Fuel Injector (연료의 물성치 변화가 이중 오리피스 연료 노즐의 분무 구조에 미치는 영향에 관한 연구)

  • Lee, Dong-Hun;Choi, Seong-Man;Park, Jeong-Bae
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.179-188
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    • 2003
  • The spray characteristics of dual orifice injector were investigated under two different fuels through measurement of SMD, number density and volume flux by using PDPA system. In this experiment, we found out that the droplet size and spray structure are strongly depend on fuel density and viscosity.

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Effects of Ambient Conditions on the Atomization of Direct Injection Injector (분위기 조건이 직접분사식 인젝터의 미립화에 미치는 영향)

  • Lee, J.S.
    • Journal of ILASS-Korea
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    • v.6 no.1
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    • pp.25-34
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    • 2001
  • Several efforts to meet the exhaust gas regulation have been undertaken by many researchers in recent years. Main researches are on development of design techniques of intake port and combustion chamber, atomisation of fuel and precise control of air-fuel ratio, post-treatment of exhaust gas and so on. Engine technology is changed from PFI to GDI to correspond with exhaust gas regulation. GDI technique makes it possible to preserve lean air-fuel ratio and control accurate air-fuel ratio. Nevertheless, It is not cleared that information of spray characteristics and atomization process are very dependent on fluctuation of pressure and change of temperature in intake stroke. In this study, a constant volume combustion chamber is manufactured to investigate various fluctuations of in-cylinder pressure for injection duration. It is taken photographs of injection process of conventional GDI injector using PMAS. Then, it was verified experimently that ambient conditions as temperature and pressure of combustion chamber have effects on process of spray growth and atomization of fuel.

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Study on Spray characteristics of Dual-Manifold Injector with Various Tangential Entries (이중 매니폴드 분사기에서 접선방향 유입구의 변화에 따른 분사특성 연구)

  • Lee, Ingyu;Jeong, Seokgyu;Yoon, Jungsoo;Park, Gujeong;Yoon, Youngbin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.10
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    • pp.868-874
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    • 2015
  • Thrust variation is an essential parameter in a space mission such as landing on an atmosphereless planet or docking a spacecraft. In order to achieve the thrust variation control, using throttleable injector is a representative and general method. A dual-manifold injector, one of throttleable injectors, was used to control mass flow rate. Five kinds of injectors were designed and investigated in order to compare the spray characteristics of the dual-manifold injector with various tangential entries. Spray angles and patterns were measured to determine external flow characteristics and film thicknesses were measured in order to investigate the internal flow patterns.

A Study on the Statistical Analysis of the Flow Characteristics of Droplet in the Cross Region of Twin Spray (이중분무 교차지역에서의 액적유동특성의 통계학적 분석에 관한 연구)

  • 조대진;윤석주;최태민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.3
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    • pp.635-644
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    • 1994
  • This study investigated mainly on the flow characteristics of a droplet in the cross region of twin spray. The velocities of the droplet were measured along the axial and radial direction, and the flow characteristics of the droplet were statistically analyzed. For the statistical analysis, the probability density of the turbulent components has been studied, and then the Reynolds shear stress, the skewness and the flatness factors were calculated, and compared with the Gaussian value. Two pressure swirl stomizers were used for the twin spray system and kerosene was employed as the working liquid. 2-D PDA(particle dynamic analyzer) was used for the purpose of the measurement of droplet size and velocities. As a result, it was found that (1) the droplets collision was taken place strongly in the cross region. So, a large momentum loss of droplets due to the loss of natural movement direction was occurred, and momentum loss of radial direction was greater than that of axial direction. (2) The axial direction skewness factor approached to zero like the Gaussian distribution in the cross region of twin spray. (3) In the cross region of twin spray, the fluctuation instability of droplet was increased because of the development of the turbulence characteristics due to the droplet collision.

Effect of Swirl Angle on the Atomization Characteristics in Twin-Fluid Nozzle with Dual Air Supplying (이중공기공급 2-유체 노즐의 선회각 변화에 따른 미립화 특성)

  • Woo, J.M.;Kim, E.S.;Kim, D.J.;Lee, J.K.
    • Journal of ILASS-Korea
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    • v.13 no.3
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    • pp.126-133
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    • 2008
  • The atomization characteristics of the dual air supplying two-fluid nozzle were investigated experimentally using PIV and PDA systems. The twin-fluid nozzle is composed of three main parts: the feeding injector to supply fluid that is controlled by a PWM (pulse-width modulation) mode, the adaptor as a device with the ports for supplying the carrier and assist air, and the main nozzle to produce sprays. The main nozzle has the swirler with four equally spaced tangential slots, which gives the injecting fluid an angular momentum. The swirl angle in the swirler varied with $0^{\circ}$, $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$. The ratios of carrier air to assist air and ALR (total air to liquid) were 0.55 and 1.23, respectively. The macroscopic behavior of the spray was investigated using PIV system, and the AMD and SMD distributions of the sprays were measured using PDA system. As a result, the SMD distribution increases along the radial distance, and it decreases with the increase of swirl angle in swirler.

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Feedback Control using Dual O2 Sensors for Improving the Conversion Efficiency of a Three-way Catalyst in a Heavy-duty CNG Engine (CNG 대형엔진에서 이중 O2 센서를 활용한 피드백 제어를 통한 삼원촉매 정화효율 향상)

  • Yoon, Sungjun;Lee, Junsun;Park, Hyunwook;Lee, Yonggyu;Kim, Changup;Oh, Seungmook
    • Journal of ILASS-Korea
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    • v.24 no.4
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    • pp.163-170
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    • 2019
  • In this study, feedback logic using dual O2 sensor values were developed to increase the purification capability of a three-way catalyst (TWC) in a compressed natural gas (CNG) engine. A heavy-duty inline 6-cylinder engine was used and the CNG was supplied to the engine through a mixer. This study consists of two main parts, namely, the proportional integral (PI) control with a front O2 sensor and the feedback control with dual O2 sensors. In the PI control experiment, effects of various parameters, such as P gain, I gain, and lean delay, on the TWC capability were identified. Based on the results of the PI control experiment, the feedback logic using dual O2 sensor values were developed. In both cases, the nitrogen oxides (NOX) emissions were nearly zero. However, the carbon monoxide (CO) emissions were reduced significant in the feedback logic with dual O2 sensors than in the PI control with the front O2 sensor.

A Visualization of the Spray from Small Liquid-rocket Engine Injector by Dual-mode Phase Doppler Anemometry (이중모드 위상도플러 속도계측기법에 의한 소형 액체로켓엔진 인젝터 분무의 가시화)

  • Jung, Hun;Kim, Jeong-Soo;Bae, Dae-Seok;Kwon, Oh-Boong
    • Journal of the Korean Society of Visualization
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    • v.8 no.4
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    • pp.60-65
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    • 2010
  • A focus is given to the breakup behavior of spray droplets issuing from a nonimpinging-type injector. The analysis has been carried out experimentally by means of the dual-mode phase Doppler anemometry (DPDA). Spray characteristic parameters in terms of axial velocity, mean diameter, velocity fluctuation, and span (width of the size distribution) of droplets are measured down the geometric axis of a nozzle orifice and on the plane normal to the spray stream with the injection pressure variations. As the injection pressure increases, the velocity and its fluctuation become higher, whereas the droplet sizes get smaller. It is also shown that the magnitudes of those parameters are smoothed out by dispersion when the droplets move downstream as well as outwardly. The atomization process is significantly influenced by the injection pressure rather than the traveling distance in the experimental condition presented.

Effect of the Swirler Angle and Aspect Ratio of Nozzle on the Mean Velocity and SMD of Twin Sprays (노즐의 스월러각과 형상비가 이중분무의 평균속도와 입경의 크기에 미치는 영향)

  • Kim, Young-Jin;Jung, Ji-Won;Choi, Gyoung-Min;Kim, Duck-Jool
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.11
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    • pp.1459-1466
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    • 2004
  • The purpose of this study is to investigate the effect of swirler angle and the aspect ratio of swirl chamber of nozzle on the characteristics of single and twin spray. The characteristics of sprays have been investigated by measuring the spray angle, droplet size and velocity. Visualization of spray was conducted to obtain the spray angle and breakup process. The spray characteristics such as droplet size and velocity were measured by Phase Doppler Anemometry(PDA). It was found that the spray angle was increased with increasing the swirler angle. For both sprays, the axial velocity and SMD were decreased with increasing the swirler angle. It was also shown that the axial velocity and SMD were decreased with increasing the aspect ratio of swirl chamber, but for the twin spray, the axial velocity and SMD were not influenced significantly by the changing the aspect ratio of swirl chamber. The effect of swirler angle on the spray characteristics was greater than the aspect ratio of swirl chamber for single spray. The nozzle pitch was one of the important factors affecting the spray characteristics of twin spray.

An Investigation on the Flow Characteristics of Water Spray Nozzle (미세 물분무 노즐의 유동특성에 관한 연구)

  • Jun, You Woo;Han, Young Tak;Kim, Chang Seob;Kim, Chang;Ryou, Hong-Sun
    • Fire Science and Engineering
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    • v.29 no.5
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    • pp.29-33
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    • 2015
  • In this study, the relations of flow rate, discharging distance and droplet size are measured in accordance with the nozzle shape. The dual type nozzles of LPN142 and LPN148, which have identical core diameter (6.0 mm) and the different radial injection angles (${\theta}_2=142^{\circ}$ and $148^{\circ}$), are manufactured. The distribution diameters with discharging distance are quantified by UL2167 test standard. The relations between discharging angle and droplet sizes, which are measured by the method of Helium-Neon laser equipment, are obtained by the empirical correlation as working pressure increase. Moreover, the extinction coefficient, which is major parameter of the radiative transport equation (RTE) is analyzed with variable droplet sizes. Thus, it is possible to opt the nozzle's shape by analyzing the relations of working pressure, spray distance, droplet size and fire characteristics at minimum allowable flow rate.

Effect of Operating Condition of Airblast Atomizer on Twin spray characteristics and interaction (공기충돌형 연료분사장치의 운용조건이 이중분무특성과 간섭효과에 미치는 영향)

  • Park, S.G.;Han, J.S.;Kim, Y.;Park, J.B.
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.1
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    • pp.9-14
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    • 1999
  • The effect of operating condition was studied experimently on the characteristics of twin sprays ejected from two airblast atomizers, within the range of the mass air-fuel ratio 1.36∼3.54. Water and nitrogen gas were used as test fluids for the experiments. Spray characteristics of liquid spray were measured with measurement of mass distribution and instantaneous image of the spray cone. Experimental results show that the maximum specify of the distribution were lowered but distributed over the larger area when the ROA ratio increased, Center of mass position did not change with increasing water mass flow, Increase of the nozzle distance has an small effect on mass distribution of interaction area but distributed over the larger area. It was also conformed that the effect of interaction near central point of collision decreased with the increase of the ROA ratio on interaction area from comparison using superposition method

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