• 한국연소학회지
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• 제1권1호
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• pp.11-18
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• 1996

The stabilization characteristics of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated by varying main fuel injection angles and auxiliary fuel injection conditions. The flame stability limits, temperature and length of recirculation zone, direct and schlieren photographs of flames were measured in order to study the stabilization mechanism of the diffusion flame. The results of this investigation are as follows. The stability limits can be improved by the condition of the kind and quanity of the injected auxiliary fuel. The length and temperature decrease with injection of auxiliary fuel, and these phenomena are remarkable when LPG is injected into the recirculation zone. When the LPG is injected into the recirculation zone, flame remains sooty. Fluctuation of fuel and main stream is generated actively by air injection.

• 대한기계학회논문집
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• 제10권3호
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• pp.367-375
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• 1986

본 연구에서는, 주분무의 착화지연기간에 미치는 보조연료 분사시기의 영향 및 공기유동을 연소장 내에 도입시켜 분무와 공기의 혼합을 적극적으로 촉진시킴에 따라 그 후의 연소과정이 어떤 영향을 받는가에 대해서 검토했다.또 소형고속 디이 젤기관에서는 분무의 연소기간을 최대한 단축 시키지 않으면 안되므로, 보조연료 분사 에 의해 그 단축목적이 어느 정도 달성될 수 있는 가능성을 제2보에서 시사한 바 있으 나 본 연구에서 더욱 상세히 검토했다.

• 한국분무공학회지
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• 제2권2호
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• pp.43-50
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• 1997

The purpose of this investigation is to carry out, the influence factor on the fuel spray characteristics for improve the engine combustion performance and exhaust omission in direct injection type diesel engine. The fuel properties, fuel spray structure and the shape or the piston surface of diesel engine play an important role of engine combustion process and exhaust emission. In order to obtain the effect of using auxiliary chamber and emulsified fuel on the fuel spray characteristics the experiment un conduct with single cylinder direct injection type diesel engine to examine the engine performance and gas emission. The results of this investigation showed that the increase auxiliary chamber volume and emulsified fuel give an effect on the fuel spray characteristics by reduced the concentration of nitric oxide emission in the combustion chamber. Also it can improve the combustion characteristics such as cylinder pressure, rate of pressure rise and rate of heat release.

• Journal of Advanced Marine Engineering and Technology
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• 제16권5호
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• pp.97-110
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• 1992

Rape-seed oil has high viscosity and high rubber content like other vegetable oils. When crude rape-seed oil obtained by a general oil extraction process is used in a diesel engine, automization condition during injection is not good and a large amount of combustion product is doposited in a combustion chamber. The improvement of a diesel engine is required to use rape-seed oil as a diesel engine fuel. In this study, the physical and chemical properties and combustion characteristics of rape-seed oil were investigated. The auxiliary aid was developed to improve automization condition and the effect of the auxiliary injection aid on the performance of a diesel engine was determined. The results are as follows. 1) Oil content of rape-seed is 45%. The exraction rate is 33%. The resuls show higher values compared to those of other vegetable oils. 2) The viscosity of rape-seed oil is 50.8 cSt and nearly 14 times of diesel oil viscosity. 3) The heating value and flash point of rape-seed oil are 9720kcal/Kg and 318$^{\circ}C$, respectively. 4) In case rape-seed oil is used as fuel, brake horse power, specific fuel consumption and brake thermal efficiency are compared to those of diesel oil. The results of rape-seed oil show 3.6%, 12.7% and 3.1% higher values. 5) Particle size of injection fuel with the auxiliary injection aid on the performance of a diesel engine was determined. The results are as follows. 1) Oil content of rape-seed is 45%. The extraction rate is 33%. The results show higher values compared to those of other vegetable oils. 2) The viscosity of rape-seed oil is 50.8 cSt and nearly 14 times of diesel oil viscosity. 3) The heating value and flash point of rape-seed oil are 9720kcal/Kg and 318.deg.C, respectively. 4) In case rape-seed oil is used as fuel, brake horse power, specific fuel consumption and brake thermal efficiency are compared to theose of diesel oil. The results of rape-seed oil show 3.6%, 12.7% and 3.1% higher values. 5) Particle size of injection fuel with the auxiliary injection aids is 100.mu.m smaller than that od injection fuel without the aid. 6) Brake horse power and brake thermal efficiency with the auxiliary injection aid increase 5.07% and 6.07%, respectively. However, specific fuel consumption decreases 3.85% with the auxiliary injection aid.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.230-238
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• 2015

The main purpose of this paper is to suggest opportunities for reducing $CO_2$ emission in energy conversion of a vehicle, focused on auxiliary energy improvement in the automotive field. As part of worldwide efforts to curb global warming and to protect the domestic industry as trade barriers, many countries have set goals to regulate greenhouse gas emissions. As an example, new $CO_2$ emission regulation in EU was expected to go into effect strictly in 2020. Therefore, global car-makers need to establish strategic responsiveness of the regulations. This paper shows $CO_2$ economic value by using the correct interpretation of the relevant laws and regulations. The $CO_2$ value analyzed using quantitative figures leads to the possibility of auxiliary(accessories, HVAC, electric apparatus etc.) technology for improving fuel economy. As a result, this study generalizes the meaning of electric power saving for each driving mode by auxiliary energy improvement.

• 신재생에너지
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• 제9권4호
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• pp.3-12
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• 2013

This paper proposes the hybrid fuel cell system that can solve disadvantages of existing fuel cell system and ensure high reliability and high stability. The system consists of PEM fuel cell, Ni-MH battery and power management system. In this system, when the power provided from the fuel cell is higher than the load power, the extra energy may be used to charge the Ni-MH battery. When the fuel cell can not provide enough energy to the load, the shortage of energy will be supplied by the Ni-MH battery. Experimental results show that the output voltage is regulated well during load variations. Also, high system efficiency is achieved.

• 동력기계공학회지
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• 제13권3호
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• pp.11-19
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• 2009

This paper introduces a conceptual design of a combined scroll expander-compressor unit for a fuel cell. Since air discharged out of the fuel cell stack has still high pressure energy, some power can be extracted from the air by directing it to pass through an expanding device. Such extracted power can be used to drive an auxiliary compressor. For this purpose, a scroll type expander coupled to a scroll type compressor was designed for a 1kW-class fuel cell. The orbiting scroll members of the expander and the compressor were made to share three of common drive shafts installed in the mid frame plate. Performance analysis for the combined expander-compressor unit showed that the installation of this unit could reduce the auxiliary power consumption in the fuel cell by about 42%.

• 한국군사과학기술학회지
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• 제19권2호
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• pp.211-217
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• 2016

The fuel cell based auxiliary power unit (APU) is promising for power source of armed vehicles due to its silence and high efficiency. Especially, the on board hydrogen generation and fed to fuel cell system was core technology of this power system. In this study, we analyzed the performance of the Auto thermal reactor (ATR) that produce the hydrogen from the fuel, integrated High temperature polymer electrolyte fuel cell (HT-PEFC) by Aspen plus software. The fuel was designed as a n-dodecane for analysis of military fuel (JP-8).

• 항공우주시스템공학회지
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• 제13권4호
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• pp.60-65
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• 2019

본 연구에서 항공기에 적용되는 보조연료탱크의 연료시스템에 대한 구조 설계 및 해석을 수행하였다. 구조 설계 결과에 대한 구조 안전성을 검토하였다. 연료시스템 구조에 적용된 재료는 알루미늄 합금 금속재이다. 구조 해석은 상용 유한 요소 해석 소프트웨어를 활용하여 구조 해석을 수행하였다. 설계 요구 조건은 구조물이 가속도 조건을 만족해야 한다. 따라서 최대 가속도 조건을 고려하여 구조 설계를 수행하였다. 본 연구를 통하여 보조연료탱크의 구조 설계 결과는 안전성을 확보한 것으로 분석되었다.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.724-729
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• 2017

회전익항공기용 연료탱크의 중요한 성능 중의 하나인 내충격성능은 충돌충격시험을 통해 검증된다. 충돌충격시험은 작용하는 하중이 매우 높기 때문에 실패 위험이 큰 시험인데, 만약, 연료탱크가 내충격 요구조건을 불만족하게 되면 항공기 전체 개발 일정에 심각한 차질을 줄 수 있다. 따라서, 초기 설계단계부터 연료탱크 충돌충격시험에 대한 수치해석을 수행하여 실물시험에서의 실패 가능성을 최소화 하려는 노력이 수행되어 왔다. 최근, 국내개발 회전익항공기의 항속거리를 증가시키기 위한 목적으로 외부 보조연료탱크 개발이 진행되고 있다. 본 연구에서는 해당 외부 보조연료탱크의 내충격 성능의 검토를 위해 현재까지 진행되어 온 충돌충격시험에 대한 수치해석 결과를 제시하였다. 수치해석 방법으로는 유체-구조 연성해석 방법인 입자법을 적용하였고, 미군사규격에서 규정하고 있는 시험조건을 해석조건으로 반영하였다. 또한, 실물 연료탱크 소재의 시편시험을 통해 기 확보된 바 있는 물성데이타를 수치해석에 적용하였다. 그 결과로 연료탱크 외피 및 피팅 부위의 등가응력을 계산하고 내부 장착품의 거동과 작용 하중을 분석함으로써 외부 보조연료탱크의 내충격성 설계를 위한 데이터 확보 가능성을 확인하였다.