• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.347-348
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• 2014

After-treatment system for gasoline direct injection engines should be considered due to the regulation standard for particle number emitted from spark ignition engine vehicles. A metal foam particulate filter, which is thought to be more proper for gasoline engines for its unique filtration and heat resistance characteristics, has been evaluated via engine dynamometer tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.8
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• pp.675-685
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• 2016

A research area on liquid rocket engine has been suggested. Downsizing through combustion pressure rise and low price are major issues to gas generator cycle engines. A very high pressure turbopump and material against oxidizer rich environment may be necessary technologies for staged combustion cycle engines. Integrated analysis saving computing time is the trend of rocket engine systems analysis area. Other important research topics are the methane engine for reusable booster to reduce the cost, 3D printing and materials for high temperature or oxidizer rich environment.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.273-275
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• 2014

An ammonia fuel system is developed and applied to both a spark ignition engine and a compression ignition engine to use ammonia as primary fuel in this study. Ammonia is injected separately into the intake manifold in liquid phase while gasoline or diesel is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline or diesel, the spark or diesel injection timing is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output with large amount of ammonia. The final goal of the study is to implement a methodology to ignite ammonia-air mixture and have complete combustion without any use of the conventional fuels.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.624-632
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• 2003

In the gasoline engine industry. there has been a trend towards the development of high performance engines with improved fuel efficiency, reduced weight and smaller sizes. These trends help to solved engine problems related to thermal load and abnormal combustion. In order to investigate these Problems, a thin film-type probe for instantaneously measuring temperatures has been suggested. A method for manufacturing such a probe was established in this study. The instantaneous surface temperature of a constant volume combustion chamber was measured by this probe and the heat flux was obtained through Fourier analysis. A peak instantaneous temperature was obtained after 55∼60 ms from ignition and the temperature increased according to an equivalence ratio and varied differently according to the position of the probe. Total heat loss during combustion period was affected by the equivalence ratio and differed widely in accordance to the position of the probe.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3326-3334
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• 1994

To theoretically predict knock occurrence in S. I. engine as a function of engine design and operating parameters, transient local temperature and pressure, mixture density of flame front in combustion period are calculated. We next determined normal combustion period and auto ignition period of end gas using the prediction method on occurrence of spark knock which we suggested. We predict knock occurrence in S. I. engine by comparing consecutively normal combustion period with the auto ignition period of end gas in combustion period. Engine design and operating parameters such as compression ratio, engine speed, spark timing, inlet temperature and pressure are taken into account in this calculations. The predicted result are well matched with the experimental results in turbocharged engine. Therefore, this method will provide the systematic guideline for designing engines in view of knocking limits.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.245-251
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• 2005

Recently, fuel reforming technology for the fuel cell vehicle has been applied to internal combustion engines, with various purpose. Syngas which is reformed from fossil fuel has hydrogen as a major component. It has better effort in combustion characteristics such as wide flammability and hig speed flame propagation. In this study, syngas was added to a gasoline engine for the improvement of combustion stability and exhaust emission in idle state. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to extend lean operation limit and ignition retard range. with dramatical reduction of engine out emissions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.237-240
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• 2006

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. Accordingly, the recent research efforts are focused on the improvement of engine efficiency and regressionrate in the hybrid rocket engine. The present study has numerically investigated the combustion processes and the flame structure in the hybrid rocket engine. The turbulent combustion is represented by the flamelet model and Low Reynolds number $k-{\varepsilon}$turbulent model is employed to reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect. Numerical results suggest that the present approach is capable of realistically simulating the combustion characteristics of the hybrid rocket engines.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2787-2796
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• 1994

The modeling of combustion process is an important part in an engine simulation program. In this study, calculated results using a conventional B-K model and the other model which is called GESIM were compared with experimentally measured data of a three-cylinder spark-ignition engine under wide range of operating conditions. The burn rates calculated from the combustion models were compared with the burn rate calculated from the one-zone heat release analysis that uses measured pressure data as an input data. As a result of the two models' comparison, the GESIM combustion model conformed to be closer to the data acquired from the experiment in wide operating ranges. The GESIM model has been improved by introducing a variable that considers the flame size, the area of flame conacting the piston surface into the model, based on the comparison between the experimental result and the calculated results. The improved combustion model predicts experimental results more precisely than that of GESIM combustion model.

• Journal of Mechanical Science and Technology
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• v.14 no.10
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• pp.1151-1158
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• 2000

Combustion analysis based on cylinder-pressure provides a mechanism through which a combustion researcher can understand the combustion process. The objective of this paper was to identify the most significant sources of cycle-to-cycle combustion variability in a spark ignition engine at idle. To analyse the cyclic variation in a test engine, the burn parameters are determined on a cycle-to-cycle basis through the analysis of the engine pressure data. The burn rate analysis program was used here and the burn parameters were used to determine the variations in the input parameter-i. e., fuel, air, and residual mass. In this study, we investigated the relationship of indicated mean effective pressure (IMEP), coefficient of variation (COV) of IMEP, burn angles, and lowest normalized value (LNV) in a spark ignition engine in a view of cyclic variations.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.9-14
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• 2002

A homogeneous premixed charge compression ignition engine has been experimentally studied far the reduction exhaust emissions of diesel engines. In this study, the gasoline fuel is injected into the intake manifold to from homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.