• Title/Summary/Keyword: optical engine

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In-Cylinder Fuel Behavior According to Fuel Injection Timing and Port Characteristics in an SI Engine : Part III-With High Swirl (가솔린 엔진에서 연료분사시기와 포트특성에 따른 실린더 내 연료거동 : Part III - 고와류의 경우)

  • 엄인용;조용석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.3
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    • pp.18-26
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    • 2001
  • This paper is the third of 3 companion papers which investigate axial stratification process. In-cylinder fuel behavior has been investigated in the port injected SI engine by visualizing for the purpose of understanding stratification. Planar laser light sheet from an Nd:YAG laser has been illuminated through the transparent quartz cylinder of the single cylinder optical engine and the Mie scattered light has been captured through the quartz window in the piston head with an ICCD camera. Fuel has been replaced with an air-ethanol mixture to utilize atomized fuel spray for the visualization purposes. This results have been compared with steady flow concentration measurement. In high swirl port, the most fuel remains at combustion chamber and upper cylinder region without being affected by injection timing. The macro-distributed state is not changed but the difference of the amount of fuel around the spark plug varies according to injection timing, which determines LML.

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A Study on the Refinement of Turbulent Flame Propagation Model for a Spark-Ignition Engine (스파크 점화기관의 난류화염전파 모델의 개선에 관한 연구)

  • 최인용;전광민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.2030-2038
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    • 1995
  • In this study, three turbulent flame propagation models are compared using experimentally measured data of a 4 valves/cylinder spark-ignition engine. First two conventional models are B.K model and GESIM combustion model. The burning rates calculated from the two models are compared with the burning rates calculated from measured pressure data using the one-zone heat release analysis. GESIM combustion model predicts burning rates closer to the data acquired from the experiment in wide operating ranges than B-K model does. The third model is refined based on GESIM combustion model by including the effect of flame stretch, turbulent length scale band pass filter and a variable that considers flame size and the area of flame contacting the cylinder wall surface. The refined combustion model predicts burning rates closer to experimental results than GESIM combustion model does. Also, the refined combustion model predicts flame radius close to the experimental result measured by using optical fiber technique.

Measurement technique for particle and soot of diesel injection by using a visualization method (가시화법을 이용한 디젤 인젝터의 액적과 soot의 측정 기술)

  • Chung, J.W.;Park, H.J.;Lee, K.H.;Lee, C.S.
    • Journal of ILASS-Korea
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    • v.6 no.2
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    • pp.22-28
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    • 2001
  • Recently, many researches have been performed to improve the combustion and emission in a D.I.Diesel engine. Especially reduction of the soot formation in the combustion chamber is the essential to acquire the improvement of the emission performance. This emission of the diesel combustion is effected by the characteristics of air-fuel mixing. Therefore, the optical measurement technique such as LII and LIS were established in order to visualize the distribution of the soot and analyze the particle including spray in the combustion chamber. In this study, we developed the algorithm for calculating relative diameter and density of particle and applied this method to measure stimultaneously the distribution of soot and spray in a D.I. diesel engine. From this experiment we found that the soot is existed in the rich region of spray and generated caused by incapable air fuel mixture.

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In-Cylinder Fuel Behavior According to Fuel Injection Timing and Port Characteristics in an SI Engine : Part I-Without Swirl (가솔린 엔진에서 연료분사시기와 포트특성에 따른 실린더 내 연료거동 : Part I-와류가 없는 경우)

  • 엄인용;조용석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.19-27
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    • 2001
  • This paper is the first of 3 companion papers which investigate axial stratification process. In-cylinder fuel behavior has been investigated in the port injected SI engine by visualization for the purpose of understanding stratification. Planar laser light sheet from an Nd:YAG laser has been illuminated through the transparent quartz cylinder of the single cylinder optical engine and the Mie scattered light has been replaced with an air-ethanol mixture to utilize atomized fuel spray for the visualization purposes. This results have been compared with steady flow concentration measurement. For no swirl port, the axial penetration depends on the fuel injection timing. The fuel tends to remain in the upper region of the cylinder far from the spark plug and the distribution is not affected by the injection timing except 90 ATDC.

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Combustion Chamber Shape Effects on Flame Temperatgure and KL Value in a Diesel Engine (디젤엔진에서 연소실 형상이 화영온도 및 KL치에 미치는 영향)

  • 이선봉;이태원;하종률
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.99-106
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    • 1999
  • The present study deals with the effect of combustion chamber shape on in-cylinder soot oxidation characteristics of a D.I . diesel engine. The analysed combustion chambers were a toroidal and a reentrant with a projection(Complex). The two-color method was used to measure in-cylinder flame temperature and KL value which is approximately proportional to the soot amount along the optical path. In addition, heat release rate was calculated from the in-cylinder pressure data. From these investigations , the soot oxidation of the reentrant and the complex which were strengthen squish flows went worse in late combustion period under heavy-load operation compared to that of the toroidal at retarded fuel injection timing . It might be the cause of the flame holding that squish lip depress the outflow of flame from the bowl to the entire combustion space.

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Backward Testing Method of MTF measurement for optical engine of CRT of rear projection HDTV (후면투사식 CRT 고화질 텔레비전용 광학엔진의 변조전달함수 측정을 위한 후방검사 변조전달함수 측정법)

  • Song, Jong-Sup;Jo, Jae-Heung;Hong, Sung-Mok;Lee, Yun-Woo;Song, Jae-Bong;Lee, Hoe-Yun;Lee, In-Won
    • Korean Journal of Optics and Photonics
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    • v.16 no.1
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    • pp.56-62
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    • 2005
  • Because of the wide plane and the curved field of CRT rear projection high definition television, its MTF(modulation transfer function) can't be easily measured by the usual forward testing method. Then we propose a backward testing method for the MTF so that the object plane and the image analyzer of forward testing are located at positions opposite each other. We prefer to use the backward testing method because the forward testing method has poor accuracy caused by very small numerical aperture, low spatial resolutions, and long depth of focus. We found that the backward testing method was very easy to align and had high repeatability. We confirmed the confidence of results obtained by the backward testing method in comparison with designed results.

The Effects of Fuel Temperature on the Spray and Combustion Characteristics of a DISI Engine (직접분사식 가솔린 엔진에서 연료 온도에 따른 팬형 분무 및 연소 특성의 변화)

  • Moon, Seok-Su;Abo-Serie, Essam;Bae, Choong-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.103-111
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    • 2006
  • The spray behavior of direct-injection spark-ignition(DISI) engines is crucial for obtaining the required mixture distribution for optimal engine combustion. The spray characteristics of DISI engines are affected by many factors such as piston bowl shape, air flow, ambient temperature, injection pressure and fuel temperature. In this study, the effect of fuel temperature on the spray and combustion characteristics was partially investigated for the wall-guided system. The effect of fuel temperature on the fan spray characteristics was investigated in a steady flow rig embodied in a wind tunnel. The shadowgraphy and direct imaging methods were employed to visualize the spray development at different fuel temperatures. The microscopic characteristics of spray were investigated by the particle size measurements using a phase Doppler anemometry(PDA). The effect of injector temperature on the engine combustion characteristics during cold start and warming-up operating conditions was also investigated. Optical single cylinder DISI engine was used for the test, and the successive flame images captured by high speed camera, engine-out emissions and performance data have been analyzed. This could give the way of forming the stable mixture near the spark plug to achieve the stable combustion of DISI engine.

Light guide based optical engine for light-valve-projection

  • Salters, B.A.;Krijn, M.P.C.M.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.935-938
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    • 2004
  • We have studied several light guide concepts for light-valve projection engines. The aim of the light guide is to replace the array of lenses and mirrors in conventional transmission-type projection engines. Volume, cost and weight can be reduced, at a similar or better performance level. Results of a first prototype are discussed.

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Optical Diagnostics for Combustion Phenomena in a Gasoline Engine (가솔린엔진의 광응용 연소계측 기술)

  • 이기형;이창식
    • Journal of the KSME
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    • v.33 no.12
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    • pp.1052-1062
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    • 1993
  • 지금까지 엔진내의 연소현상에 관한 많은 문헌들이 보고되고 있으나, 주로 계측기술에 관한 전 반적인 소개 내용이 많으며, 실제 엔진에 대한 적용 현황과 적용시 발생하는 문제점 및 해결책 등에 대한 보고는 많지않은 실정이다. 이 글에서는 필자가 경험한 계측과 가시화 기술을 중심으 로 엔진내의 연소현상 해석에 적용되는 최근의 광응용 계측기술 및 개발 동향을 소개하고자 한다.

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