• 제목/요약/키워드: ignition characteristics

검색결과 1,155건 처리시간 0.022초

킥모터 점화 초기 연소 특성 연구 (Study on Combustion Characteristics of Kick Motor Ignition Transient)

  • 고현석;길경섭;조인현
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.705-706
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    • 2010
  • 킥모터 점화기의 점화 초기 연소 특성에 대한 설계 해석 결과 초기 압력 조건에 따라 100~500 ms 범위의 점화지연이 생기는 것으로 나타났다. 개발 시험에서 점화기가 점화 초기 주 추진제를 점화시키는데 충분한 에너지를 공급할 수 있다는 것을 검증하였다.

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압축착화 엔진에서 가솔린 예혼합이 연소 및 배기 특성에 미치는 영향 (Effect of Gasoline-premixing on Combustion and Exhaust Emissions Characteristics in Compression Ignition Engines)

  • 차준표;권석주;허정윤;이창식;박성욱
    • 한국연소학회지
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    • 제15권4호
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    • pp.53-57
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    • 2010
  • The purpose of the present work is to investigate the effect of gasoline-premixing on a combustion and emissions characteristics in a compression ignition engine. For studying combustion characteristics, a combustion pressure and rate of heat release (ROHR) were measured using a single-cylinder DI compression ignition engine with a common-rail injection system and premixed fuel injection system. In addition, exhaust emissions characteristics were studied using emission analyzers and smoke meter. The experimental results showed that the case of gasoline-premixing had longer ignition delay and lower combustion pressure compared to the cases of diesel direct injection. Furthermore, premixed gasoline-air mixture reduced NOx emissions due to low peak of ROHR.

감쇠파 고주파전압의 선행방전을 이용한 Plasma jet의 전기적 기동특성에 대한 실험적 연구 (The Experimental Research On The Electrical Characteristics For The Ignition Of Plasma Jet Using The Advance Discharge Of High Frequency Voltage With Attenuation)

  • 전춘생
    • 전기의세계
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    • 제21권4호
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    • pp.27-38
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    • 1972
  • This paper discusses the characteristics about the ignition of D.C. main discharge is a plasma jet generator, manufactured for trial as non-transferred type, when the electrical energy appropriate to the ignition is supplied to the gap between the electrodes by using advance discharge of attenuating high frequency voltage generated by a high frequency oscillator with mercury spark gap. These characteristics are under the influences of (a) the length of mercury gap in high frequency oscillator and the quantity of hydrogen flow supplied to it, (b) the condenser capacity of the high frequency oscillator circuit, (c) the length of plasma jet torch in D.C. main discharge circuit and the quantity of argon flow supplied to it, (d) the circuit constants of D.C. main discharge circuit. The results for these characteristics, obtained by this research, are considered to be helpful to the designs for the ignition of a plasma jet as well as the welding arc stabilizer by high frequency discharge and the high frequency arc welder.

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메탄연료의 점화특성에 미치는 연소 생성물 희석 및 벽면온도의 영향 (The Effects of Combustion Products Dilution and Wall Temperature on the Ignition of Methane Fuel)

  • 송금미;오창보
    • 한국안전학회지
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    • 제27권5호
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    • pp.9-15
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    • 2012
  • The ignition characteristics in a confined axisymmetric coflow $CH_4$ jet were investigated numerically with the Fire Dynamics Simulator(FDS). The $CH_4$ fuel stream was diluted with main combustion product gases, such as $O_2$, $N_2$, CO, $CO_2$, and $H_2O$, and the mixed fuel stream was heated up to the sufficient temperature where a supplying fuel stream can be ignited. For the calculation of chemical reaction in the simulation, a 2-step global finite chemistry model was considered. Boundary condition for confined wall was optimized by investigating the effects of wall temperature on the ignition characteristics of fuel stream. In addition, the effects of composition of diluents in the fuel stream and fuel stream temperature on the ignition of fuel steam were investigated. The ignition characteristics of $CH_4$ stream with diluents were very sensitive to the wall temperature, composition of diluents in the fuel stream and fuel stream temperature.

최대 2 GPa 고압 환경에서 알루미늄 입자의 점화 특성 연구 (Aluminum particle ignition characteristics at high pressure condition up to 2 GPa)

  • 이경철;타이라 쯔바사;구군모;이재영;여재익
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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    • pp.5-8
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    • 2013
  • The ignition of aluminum particles under high pressure and temperature conditions is studied. The laser ablation method is used to generate aluminum particles exposed to pressures ranging between 0.35 and 2.2 GPa. A continuous wave $CO_2$ laser is then used to heat surface of the aluminum target until ignition is achieved. We confirm ignition by a spectroscopic analysis of AlO vibronic band of 484 nm wavelength. The radiant temperature is measured with respect to various pressures for tracing of required heating energy for ignition. Then the ignition temperature is deduced from the radiant temperature using the thermal diffusion equation. The established ignition criteria for corresponding temperature and pressure can be used in the modeling of detonation behavior of heavily aluminized high explosives or solid propellants.

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도장 폐기물의 자연발화에 관한 연구 (A Study on Spontaneous Ignition of Painting Waste)

  • 최재욱;목연수;옥곤;사공성호
    • 한국안전학회지
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    • 제14권2호
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    • pp.90-96
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    • 1999
  • The characteristics of spontaneous ignition of painting waste was investigated at constant ambient temperature in oven. As the results of experiments, the spontaneous ignition temperature decreased as the sample vessel became large, and the spontaneous ignition temperature of the sample in small, intermediate and large vessels was $165.5^{\circ}C$, $144.5^{\circ}C$ and $134.5^{\circ}C$ respectively. The apparent activation energy calculated by the Frank-Kamentskii's thermal ignition theory was 34.73 kcal/mol.

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HCCI 조건에 일어나는 희박 PRF/공기 혼합물의 점화특성에 관한 직접수치모사 연구 (A DNS Study of Ignition Characteristics of Lean PRF/Air Mixtures under HCCI Conditions)

  • ;유춘상
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.153-156
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    • 2012
  • Direct numerical simulations (DNSs) of ignition of lean primary reference fuel (PRF)/air mixtures under homogeneous charge compression ignition (HCCI) conditions are performed using 116-species reduced chemistry. The influence of variations in the initial temperature field, imposed by changing the variance of temperature, and the fuel composition on ignition of lean PRF/air mixtures is studied using the displacement speed analysis.

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산소농도 변화에 따른 입상활성탄의 자연발화에 관한 연구 (A Study on the Autoignition of Granulated Activated Carbon with Change of Oxygen Concentration)

  • 목연수;최재욱;류동현;최일곤;김상렬
    • 한국안전학회지
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    • 제10권2호
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    • pp.84-91
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    • 1995
  • The characteristics of critical spontaneous ignition of granulated activated carbon were investigated In atmospheres of differing oxygen concentration. At the same concentration the larger vessels yielded the lower critical spontaneous ignition temperature. At the same vessel, as the concentration of oxygen was reduced, Ignition occurred later and at higher ambient temperature, and critical spontaneous ignition temperature increased. The apparent activation energy calculated from the Frank-Kamenetskii's ignition theory appeared to be the slight different value respectively and the mean apparent activation energy was 19850㎈/㏖.

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예연소실을 갖는 점화플러그의 연소 특성에 관한 연구 (A Study on the Combustion Characteristics of Spark Plug with Pre-ignition Chamber)

  • 지명석;김진혁;유성연
    • 대한기계학회논문집B
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    • 제31권8호
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    • pp.718-723
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    • 2007
  • The new concept spark plug was developed to study its influence on the combustion characteristics of SI engine. It has pre-ignition chamber in the lower end of spark plug and flame hole, in which fresh mixture gas can be introduced without any fuel supply system. This spark plug was tested with a commercial SI engine. Fuel consumption rate, emission gas and MBT timing were measured in the engine dynamometer for various flame hole numbers, hole positions, hole sizes of the pre-ignition chamber of the spark plug. And average flame propagation speed was measured by using the head gasket ionization probe in single cylinder engine. The new concept spark plug induces fast bum in combustion compared with the conventional spark plug, and MBT(Minimum advance for Best Torque) timing was retarded about $3{\sim}5^{\circ}$ crank angle. The flame hole number, hole direction and volume of pre-ignition chamber were found to influence the combustion characteristics.

LPG-DME 압축착화 엔진에서 흡기 가변밸브 영향 (LPG-DME Compression Ignition Engine with Intake Variable Valve Timing)

  • 염기태;배충식
    • 한국자동차공학회논문집
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    • 제16권2호
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    • pp.158-165
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    • 2008
  • The combustion and exhaust emissions characteristics of a liquefied petroleum gas-di-methyl ether compression ignition engine with a variable valve timing device were investigated under various liquefied petroleum gas injection timing conditions. Liquefied petroleum gas was used as the main fuel and was injected directly into the combustion chamber. Di-methyl ether was used as an ignition promoter and was injected into the intake port. Different liquefied petroleum gas injection timings were tested to verify the effects of the mixture homogeneity on the combustion and exhaust emission characteristics of the liquefied petroleum gas-di-methyl ether compression ignition engine. The average charge temperature was calculated to analyze the emission formation. The ringing intensity was used for analysis of knock characteristics. The combustion and exhaust emission characteristics differed significantly depending on the liquefied petroleum gas injection and intake valve open timings. The CO emission increased as the intake valve open and liquefied petroleum gas injection timings were retarded. However, the particulate matter emission decreased and the nitrogen oxide emission increased as the intake valve open timing was retarded in the diffusion combustion regime. Finally, the combustion efficiency decreased as the intake valve open and liquefied petroleum gas injection timings were retarded.