• Journal of Energy Engineering
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• v.5 no.2
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• pp.138-145
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• 1996

The particulate collection at high temperature and high pressure (HTHP) is important on the advanced coal power generation system not only to improve the thermal efficiency of the system, but also to prevent the gas turbine from erosion and to meet the emission limits of the effluent gas. The specifications for particulate collection in those systems such as Integrated Coal Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) require the absolutely high collection efficiency and reliability. Advanced cyclone, granular bed filter, electrostatic precipitator, and ceramic filter have been developed for particulate collection on the advanced coal power generation system. However, rigid ceramic filters and granular bed filter among them show the best potential. The current technology of these collectors was evaluated in this paper. The experienced problems of these systems on performance, materials, and mechanical design were investigated. Ceramic candle filters has the best potential for IGCC at this moment because it has nearly the highest efficiency comparing with other filtering systems and has accumulated many reliable design data resulted from many field experiences.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.3
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• pp.154-159
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• 2016

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption, and exhaust emission control at automotive engine In this study, it is designed and used the test bed which is installed with fuel injector controller. In addition to equipped engine using CRDI by controlling the injection timing with modulator, it has tested and analyzed the engine cycle variation characteristics, as it is varied that they are the operating parameters: fuel injected quantity, injection timing, engine speed and scavenging pressure.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.2
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• pp.288-298
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• 1999

In spark ignited engines, the electrical spark not only sets the time for the onset of combustion but also is able to greatly influence the character of the initial flame growth and the subsequent combustion, and thereby can influence engine performance. The relative importance of the ignition energy is particularly high under lean or high residual gas or exhaust gas recirculation (EGR). In this study, a modeling of flame Initiation and its development is proposed. Submodels consist in representing of cylinder pressure and temperature, heat transfer to cylinder wall, and flame kernel heat transfer to ambient air and to spark plug electrodes. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy, and laminar and turbulent flame velocity.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.2
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• pp.58-68
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• 1982

It is well known to diesel engineers that the heat release pattern is one of the most important factors affecting engine performance. Thorough research in heat release pattern has materially helped the progress in high-speed diesel engine development . This paper is based on the research conducted at KAIST and Daewoo Heavy Industry last year. The purpose of this paper is to determine the heat release pattern in combustion chamber of MAN M type, the famous low-noise engine. Thermodynamic cycle simulation was performed using Whitehous-Way's heat release pattern with modified coefficients and Annand's heat transfer model. Instantaneous temperature and pressure of gas in cylinder could be determined by the numerical solution of simultaneous equation of mass conservation, equation of energy conservation, and state equation of ideal gas. Calculated results were compared with measured values in some details emphasizing upon the factors affecting rate of heat release. The agreement was fairly good and revealed why M type should have lower burning velocity at the early part of combustion in spite of high injection rate. Additional results by parametric studies were given in relation to fuel injection conditions for further application to engine development.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.7
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• pp.857-862
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• 2004

HCCI engines take advantage of high compression ratio and heat release rate, they exhibit high efficiency in compression ignition engines. HCCI engines also utilize a lean air/fuel ratio resulting in low emissions of NOx and particulate matter(PM). The objective of this research is to determine the effects of EGR rate on the combustion processes of HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine, and a heating device was installed to raise the temperature of the intake air and also to make it more consistent. In addition, a pressure sensor was inserted into each of the cylinders to investigate the differences in characteristics among the cylinders.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.751-754
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• 2002

The SFU(Solid Fuel Ram-Jet) propulsion is attractive for projectiles because of the combination of high propulsive performance and low system complexity more than conventional projectiles. The Objective of this research was to characterize the inlet aerodynamic characteristics (centerbody & pilot type) in SFRJ. Diffuser static pressure & combustion chamber pressure was tested and the AoA was changed $0^{\circ}\;and\;4^{\circ}$ at Mach number of 3.0 for performance estimate. The performance study of inlet was carried out with the Schlieren system and Supersonic cold-flow system. A Computational fluid dynamic solution is applied internal flow of inlet and the solutions are compared with experimental results.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.61-67
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• 2000

Many research works for improving a boundary lubrication performance have been executed by using solid lubricants, and been tried to apply an engine lubrication. However those general lubricants like MoS$_2$ or PTFE have not been applied on engines due to the extreme conditions such as very high temperature and pressure by combustion process in a cylinder. A copper nickel alloy fine particle has been introduced and studied. In this Paper the lubricant using the alloy Particles is applied on a marine diesel engine and assessed by the engine performance test The results showed the increase of cylinder pressure related strongly to the engine efficiency as well as the improving the engine lubrication performance.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.63-72
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• 2010

MOV(Main Oxidizer shut-off Valves) control the combustion of launch vehicle systems by the supply and the isolation of liquid oxygen to a main combustion chamber in launch vehicle systems. Moreover, the MOV should secure a constant flow rate of liquid oxygen for combustion instability in the steady operational state. Although it has been showed that a EM(Engineering Model) with a high discharge coefficient value compared with the TM(Technology Model) fills the overall performance requirements, additional design modifications in some critical parts of the EM were conducted to improve the performance. The configurations of the pressure-control body, the middle flange, and the rips of the inlet body of the EM were modified and the performance tests have been performed with test models. Consequently, the intended improvements have been verified by the performance tests.

• KSTLE International Journal
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• v.8 no.1
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• pp.11-15
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• 2007

The mechanical face seal has been tested in Korea Aerospace Research Institute (KARl) for turbopump applications. In the turbopump under current development, the mechanical face seal is installed between fuel pump and turbine to prevent a mixture of fuel and combustion gas. Generally the mechanical face seal in turbopump is exposed to severe environment because of great rotational speed, high temperature of combustion gas and high level of pressure difference. Thus a series of tests were performed to guarantee the reliability of mechanical face seal by means of simulating the practical operating conditions. The tests were conducted up to 20,000 rpm with pressure difference of 800 kPa and temperature of 620 K In addition several carbon materials for mechanical face seal were conducted to the tests to compare the life time. During the tests, the performance against leakage was monitored and the carbon wear was also measured to estimate the life of a mechanical face seal The results show that the leakage flow rates of mechanical face seal is ignorable compared to an overall flow rate of fuel pump. The carbon material which has the finest wear resistance was found during the tests. Lastly no critical failure of mechanical face seal was found during the tests and the reliability of mechanical face seal for turbopump was successfully proved.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.2
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• pp.46-53
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• 2010

The purpose of this paper is to study combustion characteristics with the different phase of oxidizer in hybrid rocket combustion. HDPE(High Density Polyethylene) as fuel and $GN_2O$(Gas $N_2O$), $LN_2O$(Liquid $N_2O$) as oxidizer were used to perform the experiments. An investigation was performed for a change of the regression rate, pressure of combustion chamber and combustion efficiency according to the variation of oxidizer phase. In case of using $LN_2O$ as oxidizer, the regression rate is not significantly different from using $GN_2O$ as oxidizer. It is considered that combustion energy is much larger than latent heat energy which was used in the evaporation of liquid oxidizer. However propulsion performance efficiency for $LN_2O$ showed lower value than for $GN_2O$. By increasing the flow rate of liquid oxidizer, heat transfer needed for vaporization of liquid oxidizer was increased, which resulted in the growth of combustion instability.