• Title/Summary/Keyword: GDI Injector

Search Result 60, Processing Time 0.024 seconds

A Study on In-cylinder Phenomena in a Swirl Type GDI Engine (스월형 GDI 엔진의 연소실내 현상에 관한 연구)

  • 김기성;박상규
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.26 no.3
    • /
    • pp.362-374
    • /
    • 2002
  • For the purpose of development of a GDI engine, the in-cylinder phenomena, such as the spray behaviors, fuel distributions, unburned fuel, and flame characteristics were investigated in a single cylinder GDI engine. The GDI engine was equipped with a swirl type electronic injector and SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used far the measurements of fuel distributions. The effects of the injector specifications, such as the spray cone angle and the offset angle on the in-cylinder phenomena were investigated. As a result, it was found that the injected fuel collided with the bottom of the bowl and moved upward along the exhaust side wall of piston bowl. This fuel vapor played an important role in the instance of spark ignition. The unburned fuel and flame characteristics were greatly influenced by the injector specifications.

In-Cylinder Phenomena in a Swirl Type GDI Engine (스월형 GDI 엔진의 연소실내 현상 연구)

  • 김기성;박상규
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2001.05a
    • /
    • pp.75-90
    • /
    • 2001
  • For the purpose of helping development of a GDI(Gasoline Direct Injection) engine, the in-cylinder phenomena, such as the spray behaviors and fuel distributions, unburned fuel, and flame characteristics were investigated in a single cylinder GDI engine. The GDI engine was equipped with a swirl type electronic injector and SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used for the measurements of the fuel distributions. The effects of the injector specifications, such as the spray cone angle and the offset angle on the fuel distributions and combustion characteristics were investigated. As a result, it was found that the injected fuel spray collided with the bottom of the bowl and moved upward along the exhaust side wall of the piston bowl. This fuel vapor played a important role in the instance of spark ignition. The injector specifications has a great influence on the flame characteristics.

  • PDF

An Investigation on the Spray Homogeneous Characteristics of a GDI Spray for Entropy Analysis Method using Laser Scattering Images (레이저 산란 영상을 이용한 GDI 인젝터의 엔트로피 해석법에 의한 분무 균일도 특성에 관한 연구)

  • 우영완;이창희;이기형;이창식
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.10 no.6
    • /
    • pp.44-50
    • /
    • 2002
  • The spray characteristics of GDI(Gasoline Direct Injection) injector affects on engine efficiency and emission of a GDI engine. Thus, many researchers have investigated the spray characteristics and the mixture formation of GDI injector. In this study, it was tried to provide the fundamental data for GDl injector design which effects on the spray macroscopic characteristics such as penetration and spray angle. In addition, the mixture formation analyzed by using entropy analysis. The entropy analysis is based on the concept of statistical entropy, and it identifies the degree of homogeneity in the fuel concentration. The results show that as injection pressure increases but as ambient pressure increases, spray penetration decreases and spray angle doesn't affected by increasing injection pressure and ambient temperature. From the entropy analysis results, we could find that the direct diffusion phenomena is a dominant factor in the formation of a homogeneous mixture at downstream of GDI spray especially in vaporizing conditions.

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
    • /
    • v.7 no.6
    • /
    • pp.65-71
    • /
    • 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.

  • PDF

Vaporizing Characteristics of Spray from Two Different GDI Injectors (분무각이 다른 GDI인젝터에 대한 증발특성)

  • Choe, Dong-Seok;Kim, Deok-Jul
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.25 no.5
    • /
    • pp.688-696
    • /
    • 2001
  • Vaporizing characteristics of two GDI injectors with different spray angles were investigated using exciplex fluorescence method. Injector I has narrower spray angle, while injector II has wider one. The exciplex system of fluorobenzene and DEMA in a non-fluorescing base fuel of hexane was employed. In quantifying concentration of fuel vapor, quenching of concentration and temperature was corrected. Droplet size and velocity were also measured by PDPA under non-vaporizing condition. From obtaining the images of liquid and vapor phases, vaporizing GDI sprays could be divided as two regions: cone and mixing regions. For injector I, vortex region was not developed. High concentration of fuel vapor due to vaporization of many fine droplets was distributed near the spray axis. For injector II, droplets with the diameter of about 10 $\mu$m were distributed in the vortex region. The vortex region had high concentration of fuel vapor due to vaporization of these droplets. Particularly, higher and lower concentrations of fuel vapor were balanced at 2ms after the start of injection for injector II.

Study on Spray Characteristics of Single-Hole GDI Injector according to Nozzle Hole Diameter - (2) Comparison of Spray Uniformity and Atomization Characteristics (노즐 홀 직경에 따른 단공 GDI 인젝터의 분무 특성 연구 - (2) 분무 균일도 및 미립화 특성 비교)

  • Park, Jeonghyun;Ro, Seungcheon;Chang, Mengzhao;Park, Suhan
    • Journal of ILASS-Korea
    • /
    • v.25 no.4
    • /
    • pp.154-161
    • /
    • 2020
  • A single spray plume is the basic unit of the entire spray plume and is an important factor in understanding the spray characteristics. However, since the multi-hole GDI injector has a narrow spray angle, the superposition of the spray plumes occurs severely. Therefore, the spray uniformity and the spray atomization characteristics of a single spray plume were analyzed in this study using a single-hole GDI injector. Five single-hole GDI injectors with different nozzle hole diameters were used in the experiment. The uniformity of the spray was evaluated through the analysis of the spray pattern images. In addition, the atomization characteristics were compared using the diameter distribution of the spray droplets obtained using PDPA. As a result, the larger diameter of the nozzle hole, the less uniformity of the spray, and the injection pressure did not have a significant effect on the spray uniformity. It is judged that the surface roughness of the injector has a greater effect on spray uniformity than the diameter of the nozzle hole. Also, the size of the spray droplets increased sharply when the diameter of the nozzle hole was 230 ㎛.

Visualization and Numerical Analysis of Non-evaporating Spray with a Swirl-Type GDI Injector (GDI 와류 분사노즐에 의한 비증발 분무의 가시화 및 수치해석)

  • 원영호;강수구
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.11 no.4
    • /
    • pp.22-28
    • /
    • 2003
  • Predictions of the fuel spray dispersion and mixing processes are very important to improve the fuel consumption and exhaust emissions in GDI engines. Numerical and experimental analysis of the sprays with a swirl injector have been conducted. A numerical analysis is carried out using KIVA-II code with modified spray models. Experimental measurements are performed to show the global spray images and the local images near nozzle tip using laser sheet visualization technique. Computed and measured spray characteristics such as spray width, tip penetration are compared, and good agreements can be achieved. The spray head vortex is stronger as the injection pressure increases, but numerical calculations cannot show the head vortex properly.

An Experimental Study on Spray Characteristics of Multi-Hole GDI Injector (다공형 GDI 인젝터의 분무특성에 대한 실험적 연구)

  • Lee, Sung-Won;Park, Sung-Young
    • Journal of ILASS-Korea
    • /
    • v.16 no.4
    • /
    • pp.201-209
    • /
    • 2011
  • Optimum engine performance is obtained when the spray characteristics is well matched to the geometry of a combustion chamber. Among many parameters governing the combustion performance in internal combustion engine, fuel supply characteristics and atomization are important performance factors. Therefore, spray characteristics of high pressure multi-hole injector has been studied experimentally. An experimental test system has been made to operate high pressure injection system and to visualize spray behavior. Spray visualization has been performed to analyze spray formation, spray cone angle, bent angle and penetration length. Spray interaction with piston has been analyzed with various injector installation angle, injection pressure and ambient pressure. Test results show that penetration length is greatly influenced by the injection pressure. Penetration length is decreased as ambient pressure increased. Spray cone angle is increased as injection pressure and ambient pressure increased. However, bent angle is not influenced by the change of injection pressure and ambient pressure. Spray cone angle distribution map is plotted using the experimental data. Fuel movement around the spark-plug has been enforced as increasing injector installation angle.

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
    • /
    • v.26 no.7
    • /
    • pp.1047-1054
    • /
    • 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.

Pan-shaped Spray Characteristics of GDI High Pressure Slit Nozzle Injector (가솔린 직접분사식 고압 슬릿 노즐 분사기의 팬형 분무 특성 고찰)

  • Song, Bhum-Keun;Kim, Won-Tae;Kang, Shin-Jae
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.13 no.6
    • /
    • pp.70-76
    • /
    • 2005
  • A new stratified charge combustion system has been introduced and developed for GDI engines. Before this new GDI system, the stratified mixture was formed by a high pressure swirl injector. But, the special feature of new system is employed of a thin fan-shaped fuel spray formed by a slit type nozzle. Also, this system has been adopted a shell-shaped piston cavity. We made high pressure gasoline injection system and investigated the fan-shaped spray characteristics such as spray tip penetration, spray angle, SMD and velocities of droplets using PDPA(Phase Doppler Particle Analyzer) system and spray visualization system to obtain the concept of the new design and the fundamental data for the next generation GDI system. The experiment was performed at the injection pressures of 5 and 9MPa under the atmospheric condition.