• 대한기계학회논문집B
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• 제24권9호
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• pp.1157-1165
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• 2000

A classic examples of the abnormal combustions are the knock and misfire, which raise noxious performance and life of the engine. A heavy knock can also cause severe damages to the engine itself, which gives more reason why it must be detected and corrected. With the response of the today's requirements, we have researched the new diagnostic system which uses the breakdown voltage characteristics between electrodes of spark plug. This breakdown voltage depends on the pressure, temperature and even the shape and material of electrodes. But there is no data of breakdown voltage in case of using the spark plug as a electrodes. So, in this study, we show the breakdown voltage characteristic by pressure and temperature in constant volume bomb, which will make it possible to diagnose the engine combustion phenomenon.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1704-1709
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• 2004

New reduced chemical kinetic mechanism for prediction of autoignition process of HSDI diesel engine was investigated. For precise prediction of the ignition characteristics of diesel fuel, mechanism coefficients were fitted by the experimental results of ignition delay of diesel spray in a constant volume vessel. Ignition delay of diesel engine on various operation condition was calculated based on the new reduced chemical mechanism. The calculation results agreed well with experimental data.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.65-72
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• 2003

In order to clarify turbulent combustion characteristics of hydrocarbon mixtures by hydrogen addition, turbulent burning velocities in a constant volume vessel were measured for both lean and rich hydrocarbon mixtures. Moreover, the configuration characteristics of turbulent flame was investigated in the wrinkled laminar flame region. A laser tomography technique was used to obtain the images of turbulent flame, and quantitative analyses were performed. As a result, the characteristics of turbulent burning velocity was shown a distinct difference with the addition rate of hydrogen between lean and rich mixtures. On the other hand, the obtained tomograms showed that the surface area of turbulent flame depends almost only on the turbulence intensity.

• 대한기계학회논문집B
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• 제21권1호
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• pp.36-48
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• 1997

In order to establish the ignition system for lean burn, the influence of the number of spark plug, spark times and spark intervals on discharge pattern of spark energy on ignitability and combustion characteristics were evaluated. It showed that, ignitability remarkably increased with the case of multiple spark ignition system than with the case of single spark and the lean limit extended fuel/air equivalence ratio by 0.1, the increase of magnitude and lasting time of capacity component and inductance component was multi spark discharge in a row.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.25-29
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• 2013

The purpose of this paper is to determine the fuel change and weight change impact on the fuel economy and emission characteristic of ICE (Internal Combustion Engine) vehicle. According to fuel type, fuel consumption and emission characteristics were measured and fuel used in this paper was gasoline, diesel, and LPG. Four vehicles with different weight were tested and the fuel economy were compared and analyzed by using scatter graph. Test was carried out using chassis dynamometer, CVS (Constant Volume Sampler), and emission measurement system. Diesel vehicle less emited $CO_2$ compared to gasoline and LPG. Even if same $CO_2$ between gasoline and LPG, there are difference fuel economy depending on carbon proportion of specific fuel. The heavier weight of vehicle, the worse of fuel economy and Better fuel economy performance on highway driving mode.

• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.829-838
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• 2002

A constant volume combustion chamber is used to investigate the flame kernel development of gasoline air mixtures under various ignition systems, ignition energies and spark plugs. Three kinds of ignition systems are designed and assembled, and the ignition energy is controlled by the variation of the dwell time. Several kinds of spark plugs are also tested. The velocity of flame propagation is measured by a laser deflection method, and the combustion pressure is analyzed by the heat release rate and the mass fraction burnt. The results represent that as the ignition energy is increased by enlarging either dwell time or spark plug gap, the heat release rate and the mass fraction burnt are increased. The electrodes materials and shapes influence the flame kernel development by changing he transfer efficiency of electrical energy to chemical energy. The diameter of electrodes also influences the heat release rate and the burnt mass fraction.

• 한국분무공학회지
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• 제5권4호
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• pp.33-39
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• 2000

The behavior of the 2-stage spray was studied by using the schlieren method with the high pressure common-rail injection system. The spray injected 2 times with the interval of $0.3ms{\sim}1.5ms$ between the 1st and the 2nd spray in a modeled combustion chamber of constant volume bomb. In this case, the quantity of injected fuel of 1st and 2nd also changed. The schlieren photograph shows that the 2nd spray goes further away than the 1st spray when the quantity of the 1st spray is less than that of the 2nd spray. The dispersion of the vapour to the combustion chamber is not affect in a 10% of 1st spray quantity. When the 1st spray quantity is more than the 2nd spray, the vapour scattering of spray is good.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.86-91
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• 2013

It is important to understand the fuel injection characteristics, particularly the atomization, penetration, and breakup, for reducing the emissions in Diesel engines because those characteristics are related to the formation of the emissions. 3-dimensional CFD code can provide a fundamental understanding of those characteristics. In this study, two different breakup models (the Reitz-Diwakar model and the Kelvin-Helmholts Rayleigh Taylor model) were validated with the experimental data in a constant volume vessel. Then, the effect of the breakup model on the characteristics of the engine combustion and emission was studied.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.78-86
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• 1995

The structure of premixed turbulent flames in a constant-volume vessel was investigated using a microprobe method. The flame potential signal having one to eight peaks was detected in the case of turbulent flames, each of them being regarded as a flamelet existing in the flame zone. Based on this consideration, the flame propagation speed, the thickness of the flame zone, the number of flamelets and the separation distance between adjacent flamelets in the flame zone were measured. The experimental resuits of this work suggest the existence of "reactant islands" behind the flame front when the turbulence was intensified to some extent. The critical(lowest) ratio of turbulence intensity to the laminar burning velocity being found to be about 0.7 for the formation of reactant islands in this experiment.

• 한국분무공학회지
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• 제19권3호
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• pp.115-122
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• 2014

As a demand for an automobile increases, air pollution and a problem of the energy resources come to the fore in the world. Consequently, governments of every country established ordinances for green-house gas reduction and improvement of air pollution problem. Especially, as international oil price increases, engine using clean energy are being developed competitively with alternative transportation energy sources development policy as the center. Bio ethanol, one of the renewable energy produced from biomass, gained spotlight for transportation energy sources. Studies are in progress to improve fuel supply methods and combustion methods which are key features, one of the engine technologies. DI(Direct Injection), which can reduce fuel consumption rate by injecting fuel directly into the cylinder, is being studied for Green-house gas reduction and fuel economy enhancement at SI(Spark Ignition). GDI(Galoine Direct Injection) has an advantage to meet the regulations for fuel efficiency and $CO_2$ emissions. However it produces increased number of ultrafine particles, that yet received attention in the existing port-injection system, and NOX. As fuel is injected into the cylinder with high-pressure, a proper injection strategy is required by characteristics of a fuel. Especially, when alcohol type fuel is considered. In this study, we tried to get a base data bio-ethanol mixture in GDI, and combustion for optimization. We set fuel mixture rate and fuel injection pressure as parameters and took a picture with a high speed camera after gasoline-ethanol mixture fuel was injected into a constant volume combustion chamber. We figured out spraying characteristic according to parameters. Also, we determine combustion characteristics by measuring emissions and analyzing combustion.