• Title/Summary/Keyword: 가솔린 직접 분사식 인젝터

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Effects of Hole Drilling Angle on Internal Flow of Gasoline Direct Injection Injector (Hole drilling angle이 가솔린 직접 분사식 인젝터의 내부 유동에 미치는 영향)

  • Kim, Huijun;Park, Sungwook
    • Journal of ILASS-Korea
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    • v.26 no.4
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    • pp.197-203
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    • 2021
  • In gasoline direct injection injectors, cavitation can be generated inside the hole because of their high injection pressure. In this paper, the effects of cavitation development in injector were investigated depending on the various hole drilling angles were investigated by a numerical method. In order to verify the internal flow model, injection rate and injection quantity of individual holes were measured. The BOSCH long tube method was used to measure the injection rate. As a result, even if the hole diameters were the same, the discharge coefficient differed by up to 10% depending on the hole angle. Moreover, if the hole drilling angle became greater than 30°, the area coefficient and the discharge coefficient decreased as the nozzle outlet was blocked due to cavitation.

Application of Fluorescence/Scattering Technique to the Measurement of Spray Droplet Size in GDI Injector (직접 분사식 가솔린 인젝터 분무의 입경 측정에 형광/산란광법의 적용)

  • Kwak, Soo-Min;Ryu, Kyeong-Hun;Choi, Bong-Seok;Kim, Duck-Jool
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.353-358
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    • 2000
  • To achieve the requirement for high fuel economy and low emissions, the research for GDI engines is recently very brisk in the whole world. This study was performed to measure distribution of average particle size in non-evaporating spray. The 2-D fluorescence/scattering images of fuel spray were captured simultaneously by visualization system composed of a laser sheet, a doubling prism, optical filters, and an ICCD camera. Using the ratio of the two light intensities, particle size distribution was obtained. The SMD measured by fluorescence/scattering technique was compared with it obtained by PDA. The experimental results show that the spray structure of GDI injector and temporal SMD distribution.

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Numerical and Experimental Study on Spray Atomization Characteristics of GDI Injector (직접 분사식 가솔린 기관 인젝터의 분무 미립화 특성에 대한 해석 및 실험적 연구)

  • Lee, C.S.;Rhyu, Y.;Kim, H.J.;Park, S.W.
    • Journal of ILASS-Korea
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    • v.7 no.3
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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.

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Fuel Spray Characteristics of GDI Injector (직분식 가솔린기관 인젝터의 연료 분무 특성)

  • Kwon, Sang-Il;Lee, Chang-Sik
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.194-201
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    • 2000
  • This paper is intended to analyze the macroscopic behavior and transient atomization characteristics of the high-pressure gasoline injector in direct-injection gasoline engine. The global spray behavior of fuel injector was visualized by shadowgraph technique. Time-resolved droplet axial and radial velocity components and droplet diameter were measured at many probe positions in both axial and radial directions by a two-component phase Doppler particle analyzer (PDPA). In order to obtain the influence of fuel injection pressure, the macroscopic visualization and experiment of particle measurement on the fuel spray were investigated at 3,5 and 7 MPa of injection pressure under different surrounding pressure in the spray chamber. The results of this work show that the fuel injection pressure of gasoline injector in GDI engine has influence upon the mean droplet diameter, mean velocity of spray droplet, the spray tip penetration, and spray width under the elevated ambient pressure.

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A Study on the Atomization Characteristic of a Gasoline Direct Injector (가솔린 직접 분사식 인젝터의 미립화 특성에 관한 연구)

  • 김봉규;이기형;이창식;홍진성
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.65-71
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    • 1999
  • Recently new engine system is being required to cope with intensive emission restriction . For this reason, GDI(Gasoline direct injection) engine system which can satisfy both as good fuel economy as diesel engine and the performance to surpass PFI gasoline engine is being development . Since fuel injection system plays a significant role in GDI engine performance, the investigation of the spray characteristics injected from GDI injector above all is indispensable for GDI system development. In this study , spray developing shape was visualized using laser sheet with Nd : YAG laser and atomization characteristics was analyzed by measuring velocities and droplet size with PDA. Utilizing these results , the basic design factor of GDI injector can be offered.

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A Study on the Measurement of Individual Spray Cone Angle from Gasoline Direct Injection Injector using Spray Pattern Analysis (분무패턴 분석을 이용한 가솔린 직접 분사식 인젝터의 개별 분무플럼 분무각 측정 방법에 대한 연구)

  • Park, Jeonghyun;Cho, Hanbin;Park, Suhan
    • Journal of ILASS-Korea
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    • v.25 no.2
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    • pp.51-59
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    • 2020
  • The purpose of this study is to propose and compare methods for measuring individual spray cone angles using spray cross-section images. In direct injection gasoline engines, it was believed that the distribution of air-fuel mixture in the combustion chamber directly affected combustion performance and emission formation. However, since gasoline direct injection (GDI) injectors have a small injection angle, interference between individual spray plumes occurs. Therefore, GDI injectors have only measured the spray angle of the entire spray. To overcome these limitations, three methods of indirectly measuring the spray cone angles of individual spray plume were presented and compared by forming sheet beams using Nd:YAG laser and acquiring spray cross-section images. Each method currently has advantages and disadvantages, and research to apply the method suitable for various GDI injectors needs to be continued.

Study on the Injection Characteristics using Injection Rate in a Direct-injection Gasoline Injector with Multi-hole (분사율을 이용한 직접 분사식 다공 가솔린 인젝터의 분사특성 연구)

  • Park, Jeonghyun;Shin, Dalho;Park, Su Han
    • Journal of ILASS-Korea
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    • v.21 no.1
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    • pp.20-28
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    • 2016
  • This paper presents an experimental study on the GDI injector with Bosch method. The injection characteristics, such as the injection quantity, the injection rate, the maximum velocity of the nozzle exit and the injection delay were studied through the change of the injection pressure, the tube pressure and energizing duration in injection rate measurement device using nheptane. The injection quantity is increased by increasing injection pressure, decreasing tube pressure or increasing energizing duration. As the difference of the injection quantity changed, the shape of injection rate was moved with a constant form. The maximum velocity of the nozzle exit showed a tendency to increase as the injection pressure is increased. However, tube pressure did not affect. Overall, it was confirmed that the closing delay is longer than the opening delay in all conditions. As the injection pressure increased, the result has a tendency to decrease the closing delay, it did not affect the opening delay. Reduction of the closing delay showed the reduction of the injection duration. the tube pressure and energizing duration did not affect the injection delay (opening delay, closing delay).

A Study on the Spray Chracteristics for a Gasoline Direct Injector by Using Entropy Analysis and PIV Methods (엔트로피 해석과 PIV를 이용한 직접 분사식 가솔린의 분무 특성에 관한 연구)

  • Woo, Young-Wan;Lee, Chang-Hee;Lee, Ki-Hyung;Lee, Chang-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.7
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    • pp.1047-1054
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    • 2002
  • To improve the fuel consumption and exhaust emission for gasoline engines, GDI(Gasoline Direct Injection) system was spotlighted to solve above requirements. Thus, many researchers have been studied to investigate the spray characteristics and the mixture formation of GDI injector. In this study, we tried to study the spray characteristics of a gasoline direct injector by using entropy analysis and PlV methods. The entropy analysis is based on the concept of statistical entropy, and it identifies the degree of homogeneity in the fuel concentration. The PlV method was adopted to determine the fluid dynamics information at the spray. From the applied results on a direct injection gasoline spray, we could find that the direct diffusion phenomena was a dominant factor in the formation of a homogeneous mixture at downstream of GDI spray especially under vaporizing ambient conditions, and mixing phenomena was also progressed by momentum exchange with induced air. In addition, the correlation between entropy and vorticity strength enabled to find their relation.

A Numerical Study on the Spray Characteristics of the Swirl-Type Gasoline Direct Injector (스월형 가솔린 직분식 인젝터의 분무특성에 대한 수치적 연구)

  • 이충훈;정수진;김우승;이기형;배재일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.9-21
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    • 2000
  • In this study, the characteristics of high-pressure swirl injector have been studied using a commercial CFD code, STAR-CD and experiment to investigate the effect of the length of orifice and swirl port on the spray characteristics. Influences of swirl port angle and initial conditions have also been examined in terms of penetration depth and Sauter`s mean diameter. Computed results of the spray characteristics are compared with experimental results. The results show that the tangential velocity at the nozzle exit decreases, but the axial velocity increases as swirl port angle is increased. Hence, the static flow rate increases, but the initial spray angle decreases with increasing the swirl port angle. It is also shown that the values of the initial SMD used as input data for spray simulation influences the penetration depth and SMD. The spray pattern from the present numerical simulation agrees well with experimental result.

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Distribution of the Concentration of Fuel Vapor in DI Gasoline Sprays Under Evaporation Condition (증발 조건에서 직분식 가솔린 분무의 증기 농도의 분포)

  • Hwang, S.C.;Choi, D.S.;Cha, K.J.;Kim, D.J.
    • Journal of ILASS-Korea
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    • v.4 no.4
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    • pp.1-8
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    • 1999
  • The concentration and spatial distribution of vapor phases in DI (Direct Injection) gasoline spray were measured quantitatively by exciplex fluorescence method. Fluorobenzene and DEMA (diethylmethylamine) in a solution of hexane were used as the exciplex-forming dopants. The fluorescence intensity of vapor phase were obtained by ICCD camera with the appropriate filter The relationship between fluorescence intensity and vapor concentration was induced fer the purpose of a quantitative analysis. The 2-D vapor/liquid images of fuel spray were captured under the evaporation condition, and the spatial distribution of vapor concentration was obtained. The spatial distribution of liquid phase had hollow-cone shape. And the vapor phase was widely distributed in the whole spray. The behavior of vapor phase was significantly affected by second flow such as entrainment, vortex, while that of liquid phase was scarcely affected.

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