• 제목/요약/키워드: SCV Angle

검색결과 10건 처리시간 0.023초

4밸브 직분식 디젤엔진의 SCV 개구율에 따른 흡입유동특성 (Intake Flow Characteristics with SCV Open Ratio in a 4-Valve Direct Diesel Engine)

  • 최승환;전충환;장영준;이진욱
    • 한국자동차공학회논문집
    • /
    • 제7권7호
    • /
    • pp.66-75
    • /
    • 1999
  • Many researchers have developed the measurement technique of in-cylinder flow. Recently, there are lots of studies on steady flow with different SCV geometries. In this study the flow characteristics of four-valve cylinder head were examined in a steady test rig for different SCV open ratios. Each swirl ratio of several SCV angle was quantified by swirl impulse meter and 2D-LDV measurement. The results showed that the swirl ratio was controlled between 2.3 and 3.8 based on SCV angles. The velocity distributions of in-cylinder flow field were measured by 2-D LDV test and visualized swirl and tumble flow pattern at different positions. In this engine , we found out that the swirl was dominant flow.

  • PDF

스월형 GDI 엔진의 연료분포특성 연구 (Fuel Distribution Characteristics in a Swirl Type GDI Engine)

  • 김기성;박상규
    • 한국마린엔지니어링학회:학술대회논문집
    • /
    • 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
    • /
    • pp.49-59
    • /
    • 2002
  • For the purpose of helping development of a GDI(Gasoline Direct Injection) engine, the spray behaviors and fuel distributions were investigated in a single cylinder GDI engine. The experimental engine is a swirl type GBI engine with a SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used for the measurement of the fuel distributions. The effects of SCV opening angle and the Injector specifications, such as the spray cone angle and the offset an91e on the fuel distributions characteristics were investigated. As a result, it was found that the SCV opening angle had a great effect on the fuel distributions in the late stage of compression process by changing flow fields in the combustion chamber.

  • PDF

SCV를 장착학 가솔린 가시화엔진에서의 연소특성 (Combustion Characteristics Using a S.I. Optically Acessible Engine with SCV)

  • 정구섭;김형준;전충환;장영준
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제25권1호
    • /
    • pp.115-123
    • /
    • 2001
  • This study describes the combustion characteristics under various condition of air excess ratio and ignition timing in a 2-valve gasoline optically accessible engine with swirl control valve(SCV). It adapted three different types of SCA(open ration 72.5%, 78%, 89%) to strengthen a swirl flow. Pressure data were acquired using pressure sensor to investigate the effect of swirl flow on combustion, and from these pressure data, IMEP(indicated mean effective pressure) and MFB(mass fraction burnt)were calculated to explain burn rate and flame speed. From acquired flame images, inspected the flame propagation direction, flame area, and flame centroid, Flame propagation direction was shown different tendency between with/without SCV, and flame area with SCV was faster and larger than that of conventional engine. Finally, the representative flame image at each crank angle were acquired by PDF method to verify flame growth process. It is found that strengthened swirl flow is more beneficial for faster and stable combustion.

  • PDF

SCV를 장착한 2밸브 Sl 가시화기관의 연소특성에 관한 연구 (A Study of the Combustion Characteristics Using a 2-valve Sl Optically Acessible Engine with SCV)

  • 정구섭;전충환;장영준
    • 대한기계학회논문집B
    • /
    • 제25권12호
    • /
    • pp.1692-1701
    • /
    • 2001
  • This study describes the combustion characteristics under various condition of air excess ratio and ignition timing in a 2-valve SI optically accessible engine with swirl control valve(SCV). It adapted three different types of SCV(open ratio 72.5%, 78%, 59%) to strengthen a swirl flow. Pressure data were acquired using pressure sensor to investigate the effect of swirl flow on combustion, and from these pressure data, IMEP(indicated mean effective pressure) and MFB(mass fraction burnt) were calculated to explain burn rate and flame speed. From acquired flame images, we inspected the flame propagation direction, flame area, and flame centroid. Flame propagation direction showed different tendency between with/without SCV, and flame area with SCV was faster and larger than that of conventional engine. Finally, the representative flame images at each crank angle were acquired by PDF method to verify flame growth process. It is found that strengthened swirl flow is more beneficial for faster and stable combustion.

스월형 GDI 엔진의 연료혼합특성 연구 (Aspects of Mixture Formation in a Swirl Type GDI Engine)

  • 김기성;박상규
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제27권2호
    • /
    • pp.260-271
    • /
    • 2003
  • For the Purpose of understanding the mixing phenomena of a GDI(Gasoline Direct Injection) engine, the spray behaviors and fuel distributions were investigated in a single cylinder transparent GDI engine. The experimental engine is a swirl type GDI engine with a SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used for the measurement of the fuel distributions. The effects of SCV opening angles and the injector specifications on the fuel distribution characteristics were investigated. As a result, it was found that the SCV opening angle had a great effect on the fuel distributions in the late stage of compression process by changing the flow fields in the combustion chamber.

스월유동이 분무특성에 미치는 영향에 관한 연구 (Study on the Effect of Swirl Flow on Spray Characteristics)

  • 최승환;전충환;장영준
    • 한국분무공학회지
    • /
    • 제7권1호
    • /
    • pp.14-20
    • /
    • 2002
  • It is well known that the flow and spray characteristics is critical factor on the performance and emission of a direct injection diesel engine. So this study aims to investigate the interaction of flow and spray characteristics. At first, in cylinder flow distributions in swirl adaptor for 4-valve cylinder head of DI Diesel engine were investigated under steady conditions for different SCV angles mounted on the cylinder head with steady rig test and 2-D LDV. And the in-cylinder flow was quantified in terms of mean flow coefficient and swirl ratio/tumble ratio. It was found that the swirl ratio is controlled between 2.3 and 3.8. Then spray characteristics of the intermittent injection were investigated. PDA system was utilized for measurement of a droplet size and velocity. The analyses of the PDA results are carried out with Time Dividing Method. It was found that there is a correlation between the swirl flow and SMD. The droplet size and the velocity were nearly constant value with each SCV angle. And the swirl ratio is higher, SMD smaller. The swirl ratio was helpful factor to the atomization of droplet.

  • PDF

Steady-Flow Characteristics and Its Influence on Spray for Direct Injection Diesel Engine

  • Jeon, Chung-hwan;Park, Seung-hwan;Chang, Young-june
    • Journal of Mechanical Science and Technology
    • /
    • 제16권7호
    • /
    • pp.986-998
    • /
    • 2002
  • Flow and spray characteristics are critical factors that affect the performance and exhaust emissions of a direct injection diesel engine. It is well known that the swirl control system is one of the useful ways to improve the fuel consumption and emission reduction rate in a diesel engine. However, until now there have only been a few studies on the effect of flow on spray. Because of this, the relationship between the flow pattern in the cylinder and its influence on the behavior of the spray is in need of investigation. First, in-cylinder flow distributions for 4-valve cylinder head of DI (Direct Injection) Diesel engine were investigated under steady-state conditions for different SCV (Swirl Control Valve) opening angles using a steady flow rig and 2-D LDV (Laser Doppler Velocimetry). It was found that swirl flow was more dominant than that of tumble in the experimented engine. In addition, the in-cylinder flow was quantified in terms of swirl/tumble ratio and mean flow coefficient. As the SCV opening angle was increased, high swirl ratios more than 3.0 were obtained in the case of SCV -70° and 90°. Second, spray characteristics of the intermittent injection were investigated by a PDA (Phase Doppler Anemometer) system. A Time Dividing Method (TDM) was used to analyze the microscopic spray characteristics. It was found that the atomization characteristics such as velocity and SMD (Sauter Mean Diameter) of the spray were affected by the in-cylinder swirl ratio. As a result, it was concluded that the swirl ratio improves atomization characteristics uniformly.

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

  • 김기성;박상규
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제26권3호
    • /
    • 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.

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

  • 김기성;박상규
    • 한국마린엔지니어링학회:학술대회논문집
    • /
    • 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
    • /
    • 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

희박연소 안정화를 위한 가스유동장 조건에 관한 연구 (Optimal Gas-Flow Conditions for Stabilization of Lean-Burn Combustion)

  • 이기형;이창식
    • 대한기계학회논문집
    • /
    • 제19권3호
    • /
    • pp.763-770
    • /
    • 1995
  • Gas flow characteristics within the cylinder is important factors in impoving lean combustion stability. This paper shows the effects of various flow fields generated by a swirl control valve(SCV) on combustion process in a 4-valve spark ignition engine. An impulse swirl/tumble meter was used to elucidation the steady-state flow characteristics, and a rotating grating type LDV was developed to measure the mean velocity and tunbulence intensity in relation to the crank angle. These methodologies were applied to clarify the correlation between gas flow characteristics and combustion stability at a lean air fuel ratio. An analysis of the correlation revealed the gas flow conditions required to optimize a lean-burn system.