• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.121-125
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• 2013

It is an analysis about electromagnetic wave which is generated from a Spark plug cable of Distributorless spark ignition system. In case of Distributorless spark ignition system, high frequency generation is an ignition coil and Spark plug cable and Spark plug could be activated with electromagnetic wave radiation antenna. I calculated a resonant frequency with HFSS by measuring length of Spark plug cable and Spark plug. The antenna was considered as ${\lambda}/4$ monopole antenna in this calculation. According to power spectrum measurement analysis of engine room radiated electromagnetic wave and calculated Resonant frequency, it is possible to find out that the Distributorless spark ignition system radiates high frequency energy in certain frequency band.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.212-219
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• 1998

Unburned hydrocarbon is a key contributor to both the fuel economy and emissions of automotive engine. Cyclic variation of HC emission is of importance, especially during throttle transients. The real time measurement of hydrocarbon is particularly important to obtain a better understanding of the mechanisms for combustion and emissions, especially during cold start and throttle transient condition. This paper reports the cycle resolved measurement technique of unburned hydrocarbons to quantify rapid changes of in-cylinder concentration in the vicinity of spark plug by using the Fast Response Flame Ionization Detector(FRFID). While this instrument actually measures fuel concentration, its results can be indicative of the AFR behaviour. In order to understand the rapid change of hydrocarbons with cylinder pressure, it is necessary to study the response time delay of the system, including the time associated with gas transportation to FID. And signal from FRFID is correlated with cylinder pressure data to relate changes in mixture preparation to the classic analysis, such as indicated mean effective(IMEF) and ignition delay, etc.

• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.27-32
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• 2013

Renewable gas fuels such as biogas and landfill gas are obtained from the biodegradable organic wastes so that they inherently have carbon-neutral nature which can respond global warming. Therefore, attentions are paid to use this renewable gases as a main fuel for internal combustion engines. However, the composition of the fuel varies by its origin or conversion process, it is necessary to make stable combustion and accomplish high efficiency when used in power generating spark ignition (SI) engines. In this study, efforts have been made to investigate the effect of the composition of renewable gas fuel on the engine performance and exhaust emissions. In addition, a new spark plug with a long electrode was tested and compared with a base spark plug as a way to improve engine efficiency and reduce harmful emissions.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.23-31
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• 2000

Knock and misfire, kinds of abnormal combustion, are highly undesirable effect on the internal combustion engine. So, it is important to detect these avnormal combuition and control the ignition timing etc. to avoid these mal-effect factors in real engine system. In this study, the system which detects the knock and the misfire using by spark plug is presented. This system is based on the effect of modulation breakdown voltage(BDV) between the spark gaps. The voltage drop between spark plug electrodes, when an electrical breakdown is initiated, depends on the temperature and pressure in combustion chamber. So, we can detect knock and misfire that produce changes in gas temperature and pressure (consequently, its density) using by BDV signal change which carries information about the character of combustion.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.18-25
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• 2000

Ion current in an S.I engine cylinder is measured with the spark plug as a probe. The peak values are confirmed to show a fair correlation with local air-fuel ration and engine speed which implies that the ion current measured at the spark plug may provide a signal for the local mixture strength which is the key parameter in precise fuel control for future engines especially of gasoline direct-injected lean burn engines.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.21-26
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• 2014

Renewable gas fuels such as biogas and landfill gas have carbon-neutral nature which can reduce carbon dioxide. However, it is necessary to make stable combustion when this fuel is used in power generating SI(spark ignition) gas engines due to its low heating value and non-uniformity. In this study, it was shown that addition of hydrogen can increase combustion stability of gas engine which is running with high inert gas composition. Thermal efficiency and emission characteristics of this engine was also investigated. In addition, a new spark plug with a long electrode was tested and compared with a base spark plug as a way to improve engine efficiency and reduce exhaust emissions.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.27-37
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• 1997

Internal combustion engine is the main source of environmental pollutants and therefore better technology is required to reduce harmful elements from the exhaust gases all over the world. Especially, harmful elements from the exhaust gases are caused by incomplete combustion of mixture inside the engine cylinder and this abnormal combustion like misfire or partial burning is the direct cause of the air pollution and engine performance degradation. the object of this research is to detect abnormal combustion like misfire and to keep the engine performance in the optimal operating state. Development of a new system therefore could be applied to a real car. To realize this, the spark-plug in a conventional ignition system is used as a misfire detection sensor and breakdown voltage is analyzed. In this research, bias voltage(about 3kV) was applied to the electrodes of spark-plug and breakdown voltage signal is obtained. This breakdown voltage signal is analyzed and found that a combustion phenomena in engine cylinder has close relationship with harmonic coefficient K which was introduced in this research. Newly developed combustion diagnostic method( breakdown voltage signal analysis) from this research can be used for the combustion diagnostic and combustion control system in an real car.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.95-100
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• 2011

The test was done on cars travelling at speeds of 20km/h, 60km/h and 100km/h, the performance testing mode for chassis dynamometer. In this test, the secondary waveform were measured, including those using faulty MAP sensors, oxygen sensors and spark plugs. The results from these measurements and their analysis of secondary waveform can be summarized as follows: 1) The secondary waveform measured from the faulty oxygen sensor showed a lot of noise around peak voltage and in the rising and falling sections during spark line which means that the air fuel mixture was non-homogeneous. 2) The secondary waveform from the faulty MAP sensor showed the worst shape compared to other sensors, including variation of spark line, state of air-fuel mixture and velocity of flame front. 3) The spark line time of secondary waveform using a faulty spark plug displayed the shortest and smallest energy spark line, which means that a misfire occurred.

• Journal of Power System Engineering
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• v.15 no.1
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• pp.11-17
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• 2011

본 연구는 라디칼 착화(Radical Ignition이하 RI) 기술을 적용한 부실직분식 CNG(Compressed Natural Gas) 엔진의 구동특성에 관한 것이다. 실험엔진은 단기통 디젤엔진을 개조하여 사용하였으며, 이는 부실식 디젤엔진처럼 연소실이 주실과 부실로 나누어져 있다. 부실에 분사된 CNG는 스파크플러그로 점화하며, 부실로 부터의 연소가스가 주실 희박 혼합기를 시켜 구동하는 엔진이다. RI 기술은 연소속도를 향상시킬 수 있다. 본 연구는 주로 저부하 RI-CNG 엔진의 성능을 연구하였다. 연료분사기간은 9 ms, 공기과잉률은 1.0, 1.2, 1.4로 하였다. 연료분사시기는 엔진의 배가밸브가 닫히는 ATDC $20^{\circ}CA$ 부터 $120^{\circ}CA$ 사이로, $20^{\circ}CA$ 간격으로 지각시켜 가며 실험하였다. 본 연구는 연료분사시기 및 공기과잉률이 연소최고압력 ($P_{max}$), 연소최고압력시기(${\Theta}_{pmax}$), 도시평균유효압력(IMEP), 사이클 변동계수($COV_{imep}$), 연소속도에 미치는 양향 등을 구하고 분석하였다.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.2
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• pp.13-21
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• 1986

점차 엄격해지는 요구조건을 만족시켜 주기 위해서는 승용차용 엔진의 실제특성과 운전특성을 지 배하는 설계변수의 조절은 불가피하며, 그중에서도 엔진의 핵심부인 연소질의 설계는 가장 중요 하다. 부분 부하에서의 SI기관의 연료경제성을 향상시키는 가장 좋은 방법이 압축비를 상승시 키는 것이므로, 앞으로의 여소실은 고압축비에서도 옥탄가가 높은 연료를 요구하는 성향을 낮 추는 특성을 갖고 있어야 한다. 새로운 엔진의 향상을 최적화하기 위하여는 quench area의 크 기와 위치 그리고 적절한 quench distance의 성질이 중요하며, 또한 연소실의 소형화, 스파크 플러크의 위치, 표면적/체적의 비 그리고 화염전파거리등도 고려에 넣어야 한다. 승용차용 엔진의 요구조건은 연소실을 피스톤 크라운에 위치시키는 용이한 방법을 통하여 해결될 수 있으며, 이 러한 형상의 연소실은 실린더 헤드에 장치한 연소실과 비교하여 다음과 같은 장점을 갖고 있다. - 스파크 플러그 주변에 연소실을 배치하기 쉽다. - 연소실 내에 quench area의 설정이 자유롭다. - 연소실 layout의 개조없이 압축비의 설정이 자유롭다. - 연소실의 조합이 간단하다. - 실린더벽으로의 열손실이 감소되어 열효율이 증대된다. - 공연비의 희박가능한계가 크다. - EGR성능이 향상되어 NOx 의 배출과 연료소비율이 감소된다. - 필요하다면 연소실실 또는 직접분사식 Diesel 기관으로서의 개조가 간단하다. 만약 생산단가가 크게 상승하지 않는다면, NOx의 배출과 연료소비율이 작으면서도, 비출력이 큰 4-밸브 연소실이 실용화 될 전망이다.