• Title/Summary/Keyword: High performance engine

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Effects of the fuel injection system on combustion in a diesel engine (디젤기관의 연소에 미치는 분사계의 영향)

  • Kwon, S. I.;Kim, W.
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.1
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    • pp.37-44
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    • 1993
  • Fuel injection system is an important tool in the exhaust emission and performance of a diesel engine. Effects of the fuel injection system in diesel combustion was investigated experimentally by measuring the performance and analyzing the combustion phenomena in a D.I. diesel engine. The selected injection parameters were nozzle opening pressure, nozzle projection length, and nozzle spray angle. From the measured results, it is shown that the fuel injection pipe diameter is an effective means to improve engine performance in a middle and high speed range and the 2 stage spring nozzle holder has the advantage of increasing the engine performance due to the initial injection pressure in a low speed range. It has been also shown that increasing nozzle opening pressure resulted in decrease in smoke, but increase in NO$_{x}$ from the engine.e.

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Development of High-Pressure Subscale Thrust Chamber for Verifying Core Technology for KSLV-II Performance Enhancement (한국형발사체 성능 고도화 핵심기술 검증을 위한 고압 축소형 연소기 개발)

  • Kim, Jonggyu;Kim, Seong-Ku;Joh, Miok;Ryu, Chulsung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.25 no.4
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    • pp.19-27
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    • 2021
  • In this study, a high-pressure subsacle thrust chamber was developed to verify the core technology for KSLV-II performance enhancement. The core technologies are the design of an injector for high-pressure combustion, development of a combustion stabilization device using the additive manufacturing technique, and the design and fabrication of mixing head and regeneratively cooled combustion chamber. The core technologies, which have been verified through the development of high-pressure subscale thrust chamber, will be used to develop large engine liquid rocket engine thrust chamber in the future.

Creep Properties of Superalloy Udimet 720 in relation to Exposed (초내열합금 U720의 노출시험에 따른 크리프 특성)

  • Kong, Y.S.;Oh, S.K.
    • Journal of Power System Engineering
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    • v.5 no.2
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    • pp.57-62
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    • 2001
  • Gas turbine performance is highly dependent on the engine performance which is closely related to the engine materials since they are exposed to severe working environments, i.e, high temperature and high stresses. For this reason, advanced materials with improved properties are required for the engine. The purpose of this research is to develop key materials technologies for aircraft industry and to tester domestic production of related parts. In this paper, the real-time prediction of high temperature creep strength and creep life for nickel-based superalloy Udimet 720(high-temperature and high-pressure the gas turbine engine materials) was performed on round-bar type specimens under pure load at the temperatures of 538, 649 and $704^{\circ}C$.

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A Study on the Combustion Characteristics of Ultra High Pressure Fuel Injection System in a Diesel Engine(I) (초고압 연료분사장치 디젤기관의 연소특성에 관한 연구(I))

  • Choi, D.S.;Rhee, Kyung-Tai
    • Journal of ILASS-Korea
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    • v.4 no.1
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    • pp.34-44
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    • 1999
  • The purposes of this study were to evaluate engine performance and to analyze smoke emission characteristics for varied injection pressures and engine operating conditions of an electronically-controlled ultra high pressure fuel injection system(UHPFIS). It was discovered that the engine performance with the present UHPFIS was far better than what was initially expected. And the UHPFIS permitted engine operation at air/fuel ratios richer than 20 : 1 without increasing smoke emissions. It was discovered that the indicated mean effective pressure was increased, while the specific fuel consumption and the amount of soot were decreased, as the fuel rail pressures were improved atomization of the fuel spray. As the intake air temperature was increased from $38\sim205^{\circ}C$ in 38 degree increments, the indicated mean effective pressure was dropped while the specific fuel consumption was increased.

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Basic Experiment of P8250 Educational Engine Performance (P8250 학습용 엔진성능의 기초 실험)

  • Lim, Chang-Su;Choi, Jun-Seop;Wang, So-Rang
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.218-231
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    • 2008
  • The purpose of this study was made for the pre-teacher of university to enhance understanding for the concept of engine performance and to provide information regarding engine performance in the institute of teacher educator. This study was carried out through engine performance experiment with The Cussons Engine Test Bed P8250, internal combustion engine, in order to analyze data quantitatively, and apply and verify factors of controlling engine performance. The main results of this study are as follows: First, power and brake horsepower increased linearly, and torque over the mid-speed as engine rps(revolution per second) decreased. Second, the change of torque and specific fuel consumption were able to be verified and the concept of engine performance was able to be understood. Third, the experimental values of brake horsepower and torque on engine performance showed the same tendency as theoretical values. Fourth, air/fuel ratio increased proportionally as engine speed increased.

Study on Inverse Modeling of a Turboprop in High Altitude Operation using Engine Performance Data (성능데이터를 이용한 고고도운용 터보프롭엔진 역모델링 연구)

  • Kong, Chang-Duk;Lim, Se-Myeong;Kim, Ji-Hyun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.3
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    • pp.16-22
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    • 2010
  • The gas turbine engine performance relies greatly on its component performance characteristics. Generally, engine manufacturers do not provide engine purchasers the component performance characteristics which can be obtained by lots of experimental tests at various operating conditions and big amount of expenses. In previous works the component maps have mostly been generated by scaling from a similar component map. However this scaling method has large error at off design points, specially in high altitude operation. Therefore this work proposes an inverse modeling method that can generate components maps of PT6A-67A turboprop engine using performance data provided by the engine manufacturer. In addition, evaluation can be made through comparison between performance analysis results using the performance simulation program including the generated compressor map and performance data.

Performance Characteristics of a Regenerative Heat Exchanger Depending on Its Porous Structure (스털링 엔진용 재생 열교환기의 다공체 구조에 따른 성능 특성)

  • Shin, Myung-Chul;Ahn, Joon;Kang, Byung-Ha
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.5
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    • pp.415-421
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    • 2012
  • Stirling engine is an external combustion engine, whose efficiency approaches that of Carnot engine with the help of a regenerator. The regenerator is a heat exchanger composed of porous medium, whose performance is dependent on the pore structure. Three types of pore structures are considered in the present study. They are wire screen, random wire and composite structure, i.e. a combination of wire screens with different hydraulic diameters. The porosity more highly affects the performance of a regenerator compared to the hydraulic diameter. The random wire can yield high effectiveness even at a high porosity. The composite mesh gives better performance when the hydraulic diameter decreases in the direction from hot side to cold side.

Study on Low Pressure Loop EGR System for Heavy-duty Diesel Engine to Meet EURO-5 NOx Regulation (LPL EGR System 적용 대형 디젤엔진의 EURO-5 NOx 규제대응에 관한 연구)

  • Lee, K.S.;Baek, M.Y.;Park, H.B.
    • Journal of Power System Engineering
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    • v.11 no.4
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    • pp.12-17
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    • 2007
  • Recently, many small and medium size diesel vehicles have been equipped with turbocharger and EGR system to get high performance and reduce $NO_x$ emissions but its application to heavy-duty diesel engine is not common yet. In this work, the simulation model for EURO-3 engine was developed using WAVE and then its performance and emission level were verified by comparing with experimental results. The possibility of current EURO-3 engine equipped with LPL EGR system which would be satisfied the EURO-5 regulation are examined. ESC 13 mode was chosen as the primary engine test mode, and the injection timing and fuel quantity were changed to compensate the lost engine performance caused by EGR. The system developed in this study shows that the current EURO-3 engine could satisfy EURO-5 $NO_x$ regulation by applying LPL EGR.

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The Comparison of Performance and Emission Characteristics between CNG Engine and Gasoline Engine (천연가스 전소엔진과 가솔린엔진의 성능과 배출가스 특성비교)

  • 김진영;박원옥;정성식;하종률
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.2
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    • pp.16-21
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    • 2003
  • Natural gas is one of the promising alternative fuels because of the abundant deposits and the cleanness of emission gas. It can be used in conventional gasoline engine without major modification. Natural gas has some advantages than gasoline i.e. the high octane number, good mixing condition because of gas and wide inflamable limit. In the present study, a $1.8{\ell}$ conventional gasoline engine is modified for using the CNG as a fuel instead of gasoline. Performance and emission characteristics are compared between gasoline and CNG with 4 cylinder SI Engine which is controlled by programable ECU. Parameters of experimentation are equivalence ratio, spark timing and fuels. We analyzed the combustion characteristics of the engine using the cylinder pressure i.e. ignition delay, combustion duration and cycle variation. As a result, CNG engine shows lower exhaust emissions but brake torque is slightly reduced compared to gasoline engine. Overall combustion duration is longer than that of gasoline because of lower burning speed.

The Engine Performance and Emission Characteristics of CNG/Diesel Dual-fuel Engine by CNG Mixing Ratio (CNG/Diesel Dual-fuel 엔진의 CNG 혼합율에 따른 엔진성능 및 배출가스 특성에 관한 연구)

  • Choi, Gun-Ho;Lim, Ock-Taeck
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.3
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    • pp.38-43
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    • 2011
  • A CNG/diesel dual-fuel engine uses CNG as the main fuel and injects a small amount of diesel as an ignition priming. This study proposed the modification of the existing diesel engine into a dual-fuel engine that injects diesel with a high pressure by common rail direct injection (CRDI) and by injecting CNG at the intake port for premixing. And experiment was progressed for understanding about effect of CNG mixing ratio. The CNG/diesel dual-fuel engine showed equally satisfactory coordinate torque and power regardless of CNG mixing ratio. The PM emission was low at any CNG mixing ratio because of very small diesel pilot injection. In case of NOx and HC, high CNG mixing ratio showed low NOx and HC emissions at low speed. At medium & high speed, low CNG mixing ratio showed low NOx and HC emissions. Therefore, it would be optimized by controlling CNG mixing ratio.