• 제목/요약/키워드: knocking

검색결과 109건 처리시간 0.023초

ECU 제어를 통한 가솔린 엔진의 노킹 특성에 관한 연구 (A Study on Characteristics of Knocking in Gasoline Engine through ECU Control)

  • 양현수;임주헌;천동준
    • 대한안전경영과학회지
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    • 제10권3호
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    • pp.109-115
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    • 2008
  • A burning principle in gasoline engine is the one of being burned, by which a mixer in air and gasoline enters a combustion chamber and causes a spark in the proper timing. This is formed, by which ECU controls the fuel-injection volume and the fuel-injection timing, and determines the performance of engine. The purpose of this study is to test the characteristics on knocking in gasoline engine with the knocking-sensor equipment and to research into the characteristics in knocking while directly controling the optimal igniting timing and the fuel-injection timing through engine ECU. Given controlling ECU by grasping the characteristics in knocking, which becomes the most problem in the engine tuning market, the tuning in a true sense will be formed in gasoline engine.

가솔린 엔진의 노킹 감소를 위한 엔진 튜닝 시험 연구 (The test research of gasoline tuning for the decrease of a knocking)

  • 양현수;천동준;이안석
    • 대한안전경영과학회지
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    • 제9권2호
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    • pp.183-194
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    • 2007
  • 1. Through this experiment, we made certain that the best distinguished frequency area of the Hyundae Beta 2.0 engine's knocking is 6.8khz. 2. Through the experiment, we checked the output power voltage condition of the logging output with the generation of a engine knocking. And wechecked up that it generated maximumly up to 11.4 V which depends on the degree of the streng.

실린더 헤더의 가속도 신호를 이용한 선박용 디젤엔진의 연소 상태 모니터링 (Combustion Condition Monitoring of the Marine Diesel Engine using Acceleration Signal of Cylinder Head)

  • 서종철;김상환;이돈출
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2009년도 추계학술대회 논문집
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    • pp.607-610
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    • 2009
  • The abnormal combustion in the running engine results to knocking which increases the pressure and temperature in the cylinder, thereby decreasing the generated power by reducing the thermal efficiency. When the temperature and pressure in the cylinder increased rapidly by knocking, abnormal combustion takes place and the engine power is decreased. To investigate the knocking phenomenon, accelerometers are installed in the cylinder head to monitor and diagnose the vibration signal. As method of signal analysis, the time-frequency analysis method was adapted for acquisition of vibration signal and analyzes engine combustion in the short time. In this experiment, after analyzing time data which is stored in the signal recorder in one unit work (4 strokes: 2 revolutions), the signal with frequency and Wavelet methods with extracted one engine combustion data was also analyzed. Then, normal condition with no knocking signal is analyzed at this time. Hereafter, the experiments made a standard for distinguishing normal and abnormal condition to be carried out in acquisition of vibration signal at all cylinders and extracting knocking signal. In addition, analyzing methods can be diverse with Symmetry Dot Patterns (SDP), Time Synchronous Average (TSA), Wigner-Ville Distribution (WVD), Wigner-Ville Spectrum (WVS) and Mean Instantaneous Power (MIP) in the cold test [2]. With signal processing of vibration from engine knocking sensor, the authors adapted a part of engine /rotor vibration analysis and monitoring system for marine vessels to prevent several problems due to engine knocking

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DRASTIC IMPROVEMENT OF THERMAL EFFICIENCY BY RAPID PISTON-MOVEMENT NEAR TDC

  • Moriyoshi, Y.;Sano, M.;Morikawa, K.;Kaneko, M.
    • International Journal of Automotive Technology
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    • 제7권3호
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    • pp.295-301
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    • 2006
  • A new combustion method of high compression ratio SI engine was studied and proposed in order to achieve high thermal efficiency, comparable to that of CI engine. Compression ratio of SI engine is generally restricted by the knocking phenomena. A combustion chamber profile and a cranking mechanism were studied to avoid knocking with high compression ratio. Because reducing the end-gas temperature will suppress knocking, a combustion chamber was considered to have a wide surface at the end-gas region. However, wide surface will lead to large heat loss, which may cancel the gain of higher compression ratio operation. Thereby, a special cranking mechanism was adapted which allowed the piston to move rapidly near TDC. Numerical simulations were performed to optimize the cranking mechanism for achieving high thermal efficiency. An elliptic gear system and a leaf-shape gear system were employed in numerical simulations. Livengood-Wu integral, which is widely used to judge knocking occurrence, was calculated to verify the effect for the new concept. As a result, this concept can be operated at compression ratio of fourteen using a regular gasoline. A new single cylinder engine with compression ratio of twelve and TGV(Tumble Generation Valve) to enhance the turbulence and combustion speed was designed and built for proving its performance. The test results verified the predictions. Thermal efficiency was improve over 10% with compression ratio of twelve compared to an original engine with compression ratio of ten when strong turbulence was generated using TGV, leading to a fast combustion speed and reduced heat loss.

가솔린 엔진에서의 노킹 현상 해석 (Investigation of the Knocking Phenomenon in SI Engines)

  • 민경덕
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제21회 KOSCO SYMPOSIUM 논문집
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    • pp.17-23
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    • 2000
  • Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

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가솔린 엔진에서의 노킹 현상 해석 (Investigation of the Knocking Phenomenon in SI Engines)

  • 민경덕
    • 한국연소학회지
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    • 제5권2호
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    • pp.29-35
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    • 2000
  • Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

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CRT의 Spot-knocking 공정에 있어서 몰리브텐 팁 전계 방출 소자 냉응극의 고장 형태 분석 (Failure Mode Analysis of Mo-tip EFA Cold-Cathode in CRT Spot-knocking Process)

  • 주병권;김훈;박종원;김남수;김동호;이윤희
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제50권8호
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    • pp.414-418
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    • 2001
  • Failure modes of Mo-tip FEA were investigated in detail as a preliminary study for the application of Mo-tip FEA to the CRT electron-gun as a cold cathode. It was identified that the destruction of Mo-tip FEA was originated from reflowing of arc-current during the spot-knocking process followed by secondary arc between gate electrode and cathode substrate. In order to prevent Mo-tip FEA from destruction due to arc-current, two kinds of methods were suggested, that is one is to provide the by-pass of the reflow current and the other is to install a current limiter in the path of gate connection line.

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HCNG 엔진의 공기과잉율 변화에 따른 노킹 특성에 관한 연구 (A Study on the Knocking Characteristics with Various Excess Air Ratio in a HCNG Engine)

  • 임기훈;박철웅;이성원;최영;김창기;이장희
    • 한국가스학회지
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    • 제17권1호
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    • pp.7-12
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    • 2013
  • 자동차 배기가스 규제가 강화됨에 따라 천연가스에 수소를 첨가하는 수소-천연가스 혼합연료(HCNG)를 기존의 압축천연가스(CNG) 엔진에 적용하려는 많은 연구들이 진행되고 있다. 그러나 수소의 높은 연소 속도로 인한 역화, 조기착화, 노킹(knocking) 등의 이상연소 발생 가능성은 엔진의 가열 또는 열효율 및 출력의 저하를 야기하는 문제점이 발생할 수 있다. 본 연구에서는 CNG 연료에 수소를 일정 부분 혼합한 HCNG 연료를 기존의 CNG 엔진에 적용하여 희박연소 한계 확장을 통해 연소 성능 개선을 확인하고, CNG와 HCNG 연료의 노킹 특성을 파악하고자 하였다. 공기과잉율의 변화에 따른 노킹 발생 조건을 관찰함으로써 HCNG 연료의 적용성 및 노킹마진을 평가하고자 하였다. HCNG 연료 사용 시 최적운전조건에서 노킹 문제없이 엔진을 운전할 수 있었으나 노킹이 일어날 수 있는 가능성이 높아져 이에 대한 대비가 필요할 것으로 판단된다.

CARS 측정 기술을 이용한 스파크 점화 기관에서의 화염 전 화학 반응에 의한 온도 변화에 관한 연구 (A Study of the Temperature Elevation Due to the Pre-flame Reaction in a Spark-Ignition Engine Using CARS Technique)

  • 최인용;전광민;박철웅;한재원
    • 한국자동차공학회논문집
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    • 제9권5호
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    • pp.9-16
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    • 2001
  • End-gas temperatures were measured using CARS technique in a conventional DOHC spark- ignition engine fueled with PRF80. The measured pressure data were analyzed using band pass filter method. The measured CARS temperatures were compared with adiabatic core temperatures calculated from measured pressures. Significant heating by pre-flame reaction in the end gas zone was observed in the late part of compression stroke under both knocking and non-knocking conditions. CARS temperatures measured at 10 crank angle degree before knock occurrence was higher than adiabatic core temperatures. These results indicate that there exist some exothermic reactions in low pressure and temperature region. CARS temperatures began to be higher than the adiabatic core temperature when the end-gas temperatures reached look. The temperature elevation due to the pre-flame reaction correlated better with CARS temperature than with cylinder pressure.

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CARS 를 이용한 스파크 점화 기관에서의 화염 전화학 반응에 의한 온도 변화에 관한 연구 (A Study of the Temperature Elevation Due to the Pre-flame Reaction Using CARS)

  • 최인용;전광민;박철웅;한재원
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
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    • pp.85-92
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    • 2000
  • End-gas temperatures were measured using CARS technique in a conventional DOHC spark-ignition engine fueled with PRF80. The measured pressure data were analyzed using band pass filter method. The measured CARS temperatures were compared with adiabatic core temperatures calculated from measured pressure. Significant heating by pre-flame reaction in the end gas was observed in the late part of compression stroke under both knocking and non-knocking condition. CARS temperatures measured at 10 crank angle degree before knock occurrence was higher than adiabatic core temperatures. These results indicate that there exist some exothermic reactions in low pressure and temperature region. CARS temperatures began to be higher than the adiabatic core temperature when the end-gas temperatures reached 700 K. The temperature elevation due to the pre-flame reaction correlated better with CARS temperature than with cylinder pressure.

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