• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.69-76
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• 2001

VCO nozzle is devised to minimize the HC emission and has been applied on some HSDI diesel engines. But it is not well reported whether VCO nozzle would be advantageous over SAC nozzle in a small HSDI diesel engine. In this paper it is presented that characteristics of VCO and SAC nozzle under common rail fuel injection system and their effects on the performance in a small HSDI diesel engine.

• Journal of the KSME
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• v.29 no.6
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• pp.618-626
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• 1989

자동차용 메타놀 연료는 석유파동 이후의 석유 대체연료라는 관점에 저공해 연료의 관점이 추가 되어 최근 그 도입에 대한 연구가 활발해지고 있다. 메타놀 자동차에 관해서는 종래의 기초검토 의 단계로부터 서서히 실용화를 향한 내구, 신뢰성을 포함한 많은 과제의 검토단계로 이행되고 있다. 수소엔진의 연구는 아직 초보단계에 있으며 안전성에 대해서는 일반이 염려하고 있는 것과 같은 위험성은 없지만 금후 자동차용으로서의 안전성에 관한 실험이 필요할 것이다. 수소의 장 점을 살려 결점을 없애기 위해서는 LH2탱크, LH2펌프 4사이클 실린더내 분사가 이상적으로 생 각되고 있다.

• Journal of Hydrogen and New Energy
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• v.16 no.1
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• pp.66-73
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• 2005

Hydrogen linear power system is estimated as the next generation power system which can obtain a performance as same as fuel cell. In order to develop Hydrogen combustion power system with high thermal efficiency, it is very important to understand the basic characteristics of hydrogen combustion and establish combustion stabilization technique of its system. In this study, RICEM(Rapid Intake Compression Expansion Machine) for researching of hydrogen combustion linear power system was manufactured and evaluated, and the basic characteristics of linear RICEM were analyzed.

• Journal of Hydrogen and New Energy
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• v.13 no.4
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• pp.287-296
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• 2002

현재 자동차의 문제점을 해결할 수 있는 가장 착실한 엔진은 수소를 이용한 연료 전지라고 판단된다. 연료전지는 화학적 에너지를 전기적 에너지로 직접 변환하는 장치이다. 순수한 연료전지 차량과 연료전지 하이브리드 차량을 비교 분석하였다. 연료전지 하이브리드 차량에서 고려하여야할 점은 효율, 연료경제성, 출력 특성 등이 있다. FUDS 싸이클 시뮬레이션 비교를 하면 하이브리드화가 순수 연료전지 차량 보다 효율이 높다. 이는 회생 제동 에너지를 이용할 수 있으며 battery를 이용하여 연료전지를 효율적인 영역에서 작동하게 할 수 있기 때문이다. Life cycle 비용은 연료전지의 크기, 연료전지의 가격, 수소의 가격 등에 지배적인 영향을 받는다. 연료전지의 가격이 고가이면 하이브리드화가 유리하나, 연료전지의 가격이 400$/kW 이하가 되면 순수한 연료전지 자동차가 비용면에서 유리 하다.

• Journal of Hydrogen and New Energy
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• v.21 no.4
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• pp.321-327
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• 2010

Current rechargeable battery cannot provide high energy density and the operational durations required. But linear engine/generators provide high energy density for portable power applications because fuel is more high density. In this paper, we suggest that basic design of powerpack using linear engine for assisting power output. Efficiency is relatively high because linear engine don't have crank mechanism compared with rotary engine. We made prototype engine and had experiments to know moving characteristic about the Linear Engine. It was possible to operate velocity at 50 Hz at the firing and pressure in cylinder was 16bar.

• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.46-51
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• 2012

This study aims to develop the performance analysis program on the staged combustion cycle of the liquid rocket engine using liquid oxygen(LOx) as oxidizer, liquid hydrogen(LH2) and RP-1 as fuel. The developed analysis program can obtain the propellant mass flow rate, the specific impulse, and representative design values of engine components for the required thrust satisfying pressure, mass flow, and energy balance conditions. The analysis results show that the the specific impulses (Isp) compared to those of the real engines have been less than 1%. With additional constraints, the program will be improved for the system optimization.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.5
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• pp.79-91
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• 2008

The present article is intended to introduce the X-51A Scramjet Engine Demonstrator-Wave Rider (SED-WR) program and its core technologies to the korean propulsion community. The X-51A program is lead by the U.S. Air Force Research Laboratory (AFRL) and is sponsored by the U.S. Defense Advanced Research Projects Agency (DARPA). Most of the contents is taken from the paper by Hank et al.[1] with the supplemental materials from additional references. X-51A is a hypersonic experimental vehicle for the flight test of the hydrocarbon fuel-cooled scramjet engine developed by the AFRL HyTech program. The scramjet engine and the hypersonic flight technologies may enter the era of practical use by the completion of the ground tests in 2008 followed by the flight tests scheduled in 2009.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.437-443
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• 2014

Engine is one of the most important parts in a rocket for completing its mission successfully. In this paper, we provide a methodology for estimating reliability and development cost of a liquid rocket engine newly developed. To estimate reliability, a baseline engine is selected considering factors whose effects on reliability are unquantifiable. Then reliability of a baseline engine is adjusted to reflect the effect of factors that can be modeled quantitatively. Using the previous Transcost engine cost expressed in terms of mass and the number of hot firing tests, the engine development cost is reexpressed in reliability and thrust requirements. Finally, a numerical example is given to illustrate the application of the methodology to a turbopump rocket engine using staged combustion cycle with LOX/LH2 propellant.

• Journal of Hydrogen and New Energy
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• v.24 no.6
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• pp.524-534
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• 2013

Gasoline direct injection(GDI) engine has a high thermal efficiency, but it has a problem to increase carbon emissions such as soot and $CO_x$. In this study, the objective is to analyze numerically a problem for adding the hydrogen during the intake stroke so as to reduce the injected amount of gasoline in GDI engines. For selection of the base model, the cylinder pressure of simulation is matched to experimental data. The numerical analysis are carried out by a CFD model with the hydrogen addition of 2%, 3% and 4% on the volume basis. In the case of 3% hydrogen addition, the injected gasoline amount is only changed to match the maximum pressure of simulation to that of the base model for additional study. It is found that the combustion temperature and pressure increase with the hydrogen addition. And NO emission also increases because of the higher combustion temperature. $CO_x$ emissions, however, are reduced due to the decrease of injected gasoline amount. Also, as the injected gasoline amount is reduced for the same hydrogen addition ratio, the gross indicated work is no significant, But NO and $CO_x$ emissions are considerably decreased. On the order hand, $CO_x$ emissions of two cases are more decreased and their gross indicated works are higher obtained than those of the base model.