• Title/Summary/Keyword: 연료 액막

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Impinging Atomization of Intermittent Gasoline Sprays (간헐 가솔린 분무의 충돌에 의한 미립화 촉진)

  • 원영호;임치락
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.5
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    • pp.174-181
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    • 1998
  • Experimental and analytical studies are presented to characterize the break-up mechanism and atomization processes of the intermittent- impinging-type nozzle. Gasoline jets passing through the circular nozzle with the outlet diameter of 0.4mm and the injection duration of 10ms are impinged on each other. The impingement of fuel jets forms a thin liquid sheet, and the break-up of the liquid sheet produces liquid ligaments and droplets subsequently. The shape of liquid sheets was visualized at various impinging velocities and angles using the planer laser induced fluorescence (PLIF) technique. Based on the Kelvin-Helmholtz wave instability theory, the break-up length of liquid sheets and the droplet diameter are obtained by the theoretical analysis of the sheet disintegration. The mean diameter of droplet is also estimated analytically using the liquid sheet thickness at the edge and the wavelength of the fastest growing wave. The present results indicate that the theoretical results are favorably agreed with the experimental results. The size of droplets decreases after the impingement as the impinging angle or the injection pressure increase. The increment of the injection pressure is more effective than the increment of the impinging angle to reduce the size of droplets.

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Experimental Study of Spray Characteristics on the Throttleable Dual Manifold Injector (이중 매니폴드 가변추력 분사기의 분무 특성에 관한 실험적 연구)

  • Youn, Jung-Soo;Kim, Sung-Hyuk;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.3
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    • pp.22-30
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    • 2011
  • There is a many way of LPRE throttling methods, high-pressure-drop systems, dual-manifold injector, gas injection, multiple chambers, pulse modulation and movable injector components. Especially dual-manifold injector is essentially combines two fixed-area injectors into a common structure, with independent feed systems controlling flow to each injector manifold. In this paper, using indirect photography and liquid film thickness measurement with various injection pressure and tangential entry diameter to decide stability of spray over a wide thrust range in dual manifold injector.

A Study of Spray Characteristics of the Rotating Fuel Nozzle with Orifice Diameters (회전연료노즐의 오리피스직경에 따른 분사특성연구)

  • Lee, Mae-Hoon;Jang, Seong-Ho;Lee, Dong-Hun;Choi, Seong-Man
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.5
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    • pp.51-56
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    • 2010
  • An experimental study was performed to understand spray characteristics of the V type rotating fuel nozzle with orifice diameters by using high speed rotational system. The experimental apparatus consist of a high speed rotational system, fuel injection system and acrylic case. The droplet size and velocity were measured by PDPA(Phase Doppler Particle Analyzer) and spray was visualized by using Nd-Yag laser-based flash photography. From the test results, droplet size is reduced with increasing orifice diameter up to the critical value. When increasing orifice diameter over than this critical value, droplet size is not decreased with increasing the orifice diameter. This is due to the irregular distribution of the liquid sheet around the inner surface of injection orifice.

Characteristics of the In-cylinder Flow and Fuel Behavior with Respect to Fuel Injection Angle and Cone Angle in the PFI Dual Injection Engine (PFI Dual Injection 엔진의 연료 분사각도와 분무각에 따른 엔진 내부 유동 및 연료 거동 특성)

  • Lee, Seung Yeob;Chung, Jin Taek;Park, Young Joon;Yu, Chul Ho;Kim, Woo Tae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.2
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    • pp.221-229
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    • 2015
  • The PFI dual injection engine using one injector per an intake port was developed for solving the DISI engine cost problem. Excellent fuel atomization and targeting of the PFI dual injection engine made enhancement on the fuel efficiency and engine power. In order to develop a PFI dual injection engine, characteristics of the in-cylinder flow and fuel behavior with respect to fuel injection angle and cone angle of the PFI dual injection engine was investigated. Numerical calculation was conducted to analyze 3D unsteady in-cylinder flow and fuel behavior using STAR-CD. The engine operating condition was 2,000rpm at WOT. As a result, the amount of intake air, evaporated fuel and fuel film according to injection angle and cone angle were presented. The results were influenced by interaction between injected fuel and intake port wall.

A Study of Spray Characteristics of the Rotating Fuel Nozzle with Orifice Diameters (회전연료노즐의 오리피스직경에 따른 분사특성연구)

  • Lee, Mae-Hoon;Jang, Seong-Ho;Lee, Dong-Hun;Choi, Seong-Man
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.258-263
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    • 2010
  • An experimental study was performed to understand spray characteristics of the V type rotating fuel nozzle with orifice diameters by using high speed rotational system. The experimental apparatus consist of a high speed rotational system, fuel injection system and acrylic case. The droplet size and velocity were measured by PDPA(Phase Doppler Particle Analyzer) and spray was visualized by using Nd-Yag laser-based flash photography. From the test results, droplet diameters are reduced with increasing orifice diameter and the optimum injection orifice diameter is 2.6 mm. When increasing orifice diameter over than 2.6 mm, droplet diameter is not decreased with increasing orifice diameter. This is due to the irregular distribution of the liquid sheet around the inner surface of injection orifice.

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Modeling of Wall Impingement Process of Hollow-Cone Fuel Spray according to Wall Geometry (벽면 형상에 따른 중공 원추형 분무의 벽 충돌 과정 모델링)

  • Shim, Young-Sam;Choi, Gyung-Min;Kim, Duck-Jool
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3467-3472
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    • 2007
  • The effects of the wall geometry on the spray-wall impingement process of a hollow-cone fuel spray emerging from a high-pressure swirl injector of the Gasoline Direct Injection (GDI) engine were investigated by means of a numerical method. The ized Instability Sheet Atomization (LISA) & Aerodynamically Progressed Taylor Analogy Breakup (APTAB) model for spray atomization process and the Gosman model were applied to model the atomization and wall impingement process of the spray. The calculation results of spray characteristics, such as a spray development process and a radial distance after wall impingement, compared with the experimental ones by the Laser Induced Exciplex Fluorescence (LIEF) technique. It was found that the radial distance of the cavity angle of 90$^{circ]$ after wall impingement was the shortest and the ring shaped vortex was generated near the wall after spray-wall impingement process.

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A Study on Homogeneous Mixture Supply in a Multi-Cylinder Spark Ignition Engine - Effect on Combustion Characteristics - (다기통 전기점화기관의 균질혼합기 공급에 관한 연구 - 연소특성에 미치는 영향 -)

  • 김물시;이용길;박경석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.8
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    • pp.2194-2200
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    • 1994
  • In an automotive spark ignition engine, it is important to form the proper mixture (air/fuel) on each driving condition for developing the stabilizing combustion and exhaust characteristics. Since most of supply fuel si attached on the inside wall of the intake manifold for unadequate nonuniformity of fuel distribution to each cylinder and mixture variation. Also it affects engine performance variation and causes noises and vibration. In this study, we verified the effect of the mixture variation which is caused by fuel liquid film in the intake manifold on combustion characteristics and engine performance.

An Experimental Study on Characteristics of Twin Spray Ejected from Two Pre Filming Airblast Atomizer (두 개의 공기충돌형 연료분사장치로부터 분사되는 이중분무특성에 관한 실험적 연구)

  • Park, Seung-Gyu;Han, Jae-Seob;Kim, Yoo;Park, Jung-Bae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1998.10a
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    • pp.6-6
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    • 1998
  • 항공기용 가스터빈 및 일반적인 산업용 분무시스템에서는 많은 양의 분사액체를 미립화 시키고 시스템의 연속적인 운전과 유지를 편리하게 하기 위하여 여러 개의 분사노즐을 열로 설치하여 동시에 분사하도록 하고 있다. 이렇게 동시에 분사할 경우, 노즐간에 거리가 충분히 크지 않으면 개별적으로 분사된 분무들이 서로 합해져서 하나의 연합된 분무군이 형성된다. 이렇게 Two element에 의해서 형성된 spray는 공급압력이 증가함에 따라 관성력이 증가하게 되어 중심부분에서 액막 혹은 액적상태로서 충돌이 발생하여 복잡한 분무특성을 가질 것이다. 따라서, 연합된 분무군의 특성을 이해하는 것은 응용의 측면에서 매우 중요하다고 할 수 있다.

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Behavior of Impinging Droplet on a Solid Surface for the Variation of Fuel Temperature (연료 온도 변화에 따른 평판 충돌 액적의 거동에 관한 연구)

  • Lee, Dong-Jo;Kim, Ho-Yong;Chung, Jin-Taek
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.167-173
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    • 2003
  • An experimental study on the behavior of droplets impinging on a solid flat surface was carried out in the present study. Breakup of a liquid droplet impinging on a solid surface has been investigated experimentally for various fuels with different properties. The fuel temperature and incident angle were chosen as major parameters. And fuel temperature and incident angle varied in the range from $-20^{\circ}C$ to $30^{\circ}C$ and from $30^{\circ}$ to $60^{\circ}$, respectively, were investigated. It was found that the variation of fuel temperature influences upon droplet mean diameter which were bounced out from the solid surface. As the increases of incident angle, the break-out mass flow rate increases. This causes the decrease of liquid film flow rate. The larger incident angle gives less liquid film flow rate.

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Effect of Non-Uniform Mixture on the 4 Cylinder S.I.Engine Performance (4기통 전기점화기관의 혼합기 불균일화가 기관성능에 미치는 영향)

  • 김물시;진성호;박경석;이용길
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.4
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    • pp.72-79
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    • 1994
  • In an automotive spark ignition, it is important to form the proper mixture(air/fuel) on each driving condition for developing the stabilizing combustion and exhaust characteristics. Since most of supply fuel is attached on the inside wall of the intake manifold for unadequate atomization by fuel injection system, it brings a bad effect on combustion and exhaust caused by nonuniformity of fuel distribution to each cylinder and mixture variation. Also it affects engine performance variation and causes noises and vibration. In this study, we verified the effect of the mixture variation which is caused by fuel liquid film in an intake manifold on combustion characteristics and engine performance.

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