• Title/Summary/Keyword: Phase Doppler Particle Analyzer (PDPA)

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An Experimental Study on the Measurement of the Droplet-Air Relative Velocity in the Multi-hole Diesel Spray (다공 디젤분무의 액적-공기 상대속도 측정에 관한 실험적 연구)

  • Kweon, M.H.;Shin, S.H.;Lee, J.K.;Kang, S.J.;Rho, B.J.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.801-806
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    • 2000
  • This experimental study is to investigate the intermittent spray characteristics of a multi-hole nozzle in a heavy-duty DI diesel engine. Multi 8 hole$(d_n=0.25mm)$, Multi 3 hole$(d_n=0.42)$ and Sing hole nozzle$(d_n=0.25mm)$ were used in this experiment. By using the 2-D PDPA(phase Doppler particle analyzer), the droplet diameter and the velocity of a diesel spray injected intermittently from the multi and the single-hole nozzle into a still ambient were measured. In order to calculate the mean values such as mean velocity, SMD, AMD etc. and to analyze the intermittent characteristics, the time-window of 0.15ms were applied. In the spray, the small droplet$(D<10{\mu}m)$ was regarded as an air flow, and the correlation between the fuel droplet$(10{\mu}m and the air (low was examined. The normalized axial droplet-air relative velocity of the 8 hole, the 3 hole and the single hole nozzle was evaluated as 0.081, 0.067, 0.06 and in case of the radial droplet-air relative velocity, the normalized. value is 0.014, 0.013 and 0.008 respectively.

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Analysis of the Spray Distribution Characterization of Impinging Jet Injectors for Liquid Rockets Using PLIF Technique (PLIF 기법을 이용한 액체로켓용 충돌분사 인젝터의 분무분포 특성 해석)

  • 정기훈;윤영빈;황상순
    • Journal of the Korean Society of Propulsion Engineers
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    • v.4 no.1
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    • pp.36-45
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    • 2000
  • Most researches for impinging jet spray have been focused on under-standing the breakup mechanism of a liquid sheet formed by the collision of jets and modeling the spray breakup using experimental data. For this reason, there have been few studies on the characteristics of the spatial spray distribution which affects significantly the combustion efficiency. Hence, we measured the radial distribution of fuel massflux using a like-doublet type injector. Instead of PDPA(Phase Doppler Particle Analyzer) which has been used only for the point measurement of the drop size of spray, PLIF(Planar Laser Induced Fluorescence) technique was developed lot the 2-D measurement of the massflux distribution of spray Indirect photography technique was also used to verify PLIF data.

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Phase Doppler Measurements and Probability Density Functions in Liquid Fuel Spray (연료분무의 위상도플러 측정과 확률밀도함수의 도출)

  • 구자예
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.4
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    • pp.1039-1049
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    • 1994
  • The intermitternt and transient fuel spray have been investigated from the simultaneous measurement of droplet sizes and velocities by using Phase/Doppler Particle Analyzer(PDPA). Measurement have been done on the spray axis and at the edge of the spray near nozzle at various gas-to-liquid density ratios(.rho./sub g//.rho./sub l/) that ranges from those found in free atmospheric jets to conditions typical of diesel engines. Probability density distributions of the droplet size and velocity were obtained from raw data and mathematical probability density functions which can fit the experimental distribations were extracted using the principle of maximum likelihood. In the near nozzle region on the spray axis, droplet sizes ranged from the lower limit of the measurement system to the order of nozzle diameter for all (.rho./sub g/ /.rho./sub l/) and droplet sizes tended to be small on the spray edge. At the edge of spray, average droplet velocity peaked during needle opening and needle closing. The rms intensity is greatly incresed as the radial distance from the nozzle is increased. The probability density function which can best fit the physical breakage process such as breakup of fuel drops is exponecially decreasing log-hypebolic function with 4 parameters.

Fuel Spray Characteristics of Dimethyl Ether (DME 연료의 분무 특성에 관한 연구)

  • Lee, Sang Hoon;Chon, Mun Soo
    • Journal of Institute of Convergence Technology
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    • v.3 no.2
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    • pp.51-56
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    • 2013
  • This paper describes the atomization characteristics, as well as the velocity and size distribution, of DME spray based on common-rail injection system. To analyze the possibility of using DME fuel as an alternative fuel of diesel, spray atomization characteristics were investigated. For this investigation, two-dimensional phase Doppler analyzer system was used to obtain droplet size and velocity distribution simultaneously. Velocity and droplet size measurements were performed at various injection pressures. Results showed that increasing pressure from 25MPa to 50MPa leads to higher spray droplet velocities and smaller droplet diameter but injection pressure above 40MPa, no signifiant reduction was observed. With the droplet velocity and SMD comparison between diesel and DME fuel, it can be observed that DME has smaller SMD and droplet velocity due to its low surface tension.

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Atomization Characteristics of a Double Impinging F-0-0-F Type Injector with Four Streams for Liquid Rockets

  • Kang, Shin-Jae;Rho, Byung-Joon;Oh, Je-Ha;Kwon, Ki-Chul
    • Journal of Mechanical Science and Technology
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    • v.14 no.4
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    • pp.466-476
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    • 2000
  • This paper presents atomization characteristics of a double impinging F -0-0- F type injector with four streams. A phase Doppler particle analyzer was employed to measure the droplet-size and water was used as the inert simulant liquid instead of reactive propellant liquids. The droplet mean diameter (SMD) and size distribution were measured to investigate the effects of the momentum ratio and pressure drop variations. This experimental results can be used during the preliminary design stage of a impinging stream type injector for liquid rockets.

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The Characteristics of a Transient Liquefied Butane Spray using PDPA and High Speed Camera (PDPA와 고속카메라에 의한 액상부탄 간헐분무 특성 연구)

  • 윤준규;임종한;김종현
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.3
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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.

A Study on the Atomization Characteristics of Effervescent Atomizer with PDPA (PDPA를 이용한 기체주입미립화기의 미립화 특성에 관한 연구)

  • Kim, Hyung-Gon;Yano, Toshiaki;Song, Kyu-Keun;Jung, Byong-Koog;Jung, Jae-Youn;Cho, Tae-Young
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1316-1321
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    • 2004
  • An experimental study is performed on atomization characteristics and stable operating condition for injection of high viscous waste vegetable oil using effervescent atomizer with two aerator tubes. Consideration is given to the effects of ALR and liquid viscosity on the velocity and mean diameter of the injected droplet. It is found that (i) as ALR increases, the axial velocity of the droplet is increased, while half-velocity width and SMD are decreased regardless of the change in liquid viscosities, (ii) the rate of fine drop distribution occupied in the total spray field is increased with an increasing in ALR, and (iii) the effect of viscosity on atomization characteristics is minor.

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Study on Spray Characteristics of Barbotage Injector for Scramjet Engine (스크램제트 엔진용 Barbotage injector의 분무 특성에 관한 연구)

  • Lee, Jinhee;Lee, Sanghoon;Yang, Inyoung;Lee, Kyungjae;Kim, Jaeho;Yang, Sooseok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.236-239
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    • 2017
  • A part of the development of Scramjet Engine, this study was performed about Injectors. Barbotage injectors were used for experiment. To study characteristics of injector spray, water is supplied as a main fuel and Nitrogen is supplied for water atomization. Spray test facility and PDPA equipment were used in KARI(Korea Aerospace Research Institute). It was found that gas pressure change and spray distance is important value to spray atomization.

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INFLUENCE OF ALR ON DISINTEGRATION CHARACTERISTICS IN PNEUMATIC SPRAY

  • Lee, S.G.;Joo, B.C.;Kim, K.C.;Rho, B.J.
    • International Journal of Automotive Technology
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    • v.1 no.2
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    • pp.95-100
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    • 2000
  • The droplet and the turbulent characteristics of a counterflowing internal mixing pneumatic nozzle mainly focused. The measurements were made using a Phase Doppler Particle Analyzer under the different air pressures. The nozzle with tangential-drilled holes at an angle of 30 to the central axis has been designed. The spatial distributions of velocities, fluctuating velocities, droplet diameters and SMD were quantitatively and qualitatively fluctuating velocities were substantially higher than the radial and the tangential ones. This implies that the disintegration process is enhanced with the higher air pressure. The larger droplets were detected near the spray centerline at the upstream while the smaller ones were generated at the downstream. This was attributed to the lower rates of spherical particles which were not subject to instantaneous breakup. However, substantial increases in SMD from the central part tower spray periphery were predictable in downstream regions.

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A Study of Two-Phase Swirl Spray Characteristics on Dual Airblast Velocity Ratio (이중공기공급 속도비에 따른 이류체 선회분무 특성 연구)

  • Kang, S.J.;Oh, J.H.;Song, K.J.;Rho, B.J.
    • Journal of ILASS-Korea
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    • v.5 no.3
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    • pp.27-36
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    • 2000
  • In this study, spray characteristics of a dual airblast atomizer are addressed. Three dimensional characteristics of a dual airblast atomizer with air swirl are measured to provide the significant data. The liquid flow rate was fixed at 0.06 kg/min, and atomizing air was controlled at the liquid-air mass ratio of 4.0. The performance of the spray with co-swirl and counter-swirl flow was investigated at each point in the developed spray region using a three-component phase Doppler particle analyzer. This instrument was also used to evaluate the concentration profiles. The three dimensional mean velocity were investigated of present flow characteristics of the dual airblast atomizer. In addition, drop size distributions, mean droplet size profile, and droplet concentration were analyzed to understand atomization characteristics. This experimental results can be conveniently utilized for the preliminary design of gas turbine engines for aircraft.

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