• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.375-381
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• 2010

Cetane number of diesel fuel for compression ignition engine is one of main properties for fuel ignition quality. Recently the cetane index has been replaced the cetane number in order to resolve the disadvantage of CFR engine test, but these two value have slightly difference values due to addition of various additives. In this study, we analyzed the cetane number, derived cetane number and cetane index for diesel fuel which was blended with various ratios of biodiesel, kerosene and cetane improver as additives. As a result, Cetane number showed the similar value with derived cetane number, but cetane index showed quite different value with cetane number when biodiesel and cetane improver were used as additives.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.596-603
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• 2020

In this study, a mathematical model for optimal operation of the fusion fuel cycle is developed based on scheduling approach. The fusion fuel cycle consists of a system for storing and supplying deuterium and tritium, and receiving and separating process after the fusion reaction. Except that tritium is a radioactive material, most of these processes consist of catalytic reactions and separation process. For these reasons, it is possible to apply scheduling approach which is also widely utilized to chemical plants to derive the optimal operating scenarios. The developed model determined the optimal regeneration cycle to minimize the amount of tritium inside the vacuum pumps. Based on the characteristics of various device in the fusion reactor, the optimal tritium plant operation scenario is evaluated. The formulated model was applied to the actual tokamak scenario and utilized to analyze the fuel flow and balance of ITER fuel cycle.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.35-39
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• 2011

The purpose of this paper is to analyze affecting ratios of strength safety in carbon fiber layer thickness of a composite fuel tank for FEV vehicles. To investigate affecting ratios by FEM modeling, the equivalent von Mises stress has been computed on the aluminum liner and carbon fiber layers of composite fuel tanks in hoop and helical directions respectively. According to the FEM results, the affecting ratios of an aluminum liner on the equivalent stress are 77.5% in hoop direction, 18.11% in $70^{\circ}C$ winded helical direction and 4.39% in $12^{\circ}C$ winded helical direction. These trends on the strength safety of carbon fiber layers have been shown as those of an aluminum liner even though the layer thickness ratio of $12^{\circ}C$ inclined carbon fiber is very high of 42% compared with that of hoop layer thickness. Thus, the computed results show that the strength safety of a carbon fiber fuel tank is more influenced by the winding angle rather than the fiber thickness of carbon fiber layers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.407-416
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• 2007

Fuel spray nozzle has a critical effect on combustion characteristics. Mass flow rate and SMD(sauter mean diameter) were selected as design variables by using the experiment data of various types of duplex fuel nozzles for the swirl atomizers. The sensitivity of each design variable on the mass flow rate and SMD was analyzed and the uniformity of mass flow rate was investigated through the shape optimization of duel-orifice-type swirl atomizers. The design variables that have a little effect on the optimum design were excluded using the DOE(design of experiments) method, which enabled the optimization of sensitive design variables on mass flow rate and limit tolerance. The SMD of the research spray nozzle that was used in this study was found to be most similar to that of the calculation results using the Jasuja's SMD relationship. This study showed the specific characteristics of duel orifice type swirl atomizers and the optimization of these kinds of nozzle. This study provided the optimization design of mass flow rate and its allowable tolerance.

• Journal of the Korean Institute of Gas
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• v.26 no.4
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• pp.1-8
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• 2022

DME, a clean fuel that is being studied as an alternative fuel for diesel engines, can reduce exhaust gas, which is the one of the crucial problems of diesel engines, and has a very high cetane number and high oxygen content. DME is a fuel has properties similar with LPG and can use the infrastructure of LPG. In this study, The target was to build a database of basic data on the mass flow rate discharged for the performance evaluation of the plunger-type high pressure pump. In this study, the mass flow rate of the DME plunger type high pressure pump was analyzed by changing the common rail pressure and the motor rotation speed. The experimental conditions were the common rail pressure was changed from 300 to 500 bar and the motor rotation speed was changed from 300 to 1000 rpm. In addition, basic mass flow data were constructed to high-pressure pumps for DME. As a result of the experiment, in both cases the mass flow rate was increased.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.83-88
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• 1999

인발식 마늘 수확기의 기본개념은 마늘줄기가 인발 가이드를 따라 마늘줄기 인발부로 안내되어 지면 상방향으로 인발, 이송되는 방식으로서 인력에 의한 마늘수확 메카니즘과 유사하다. 그러나 수확기가 전진함에 따라 마늘이 연속적으로 인발되어 인력작업에 비해 매우 높은 수확능률을 갖는다. 또한 굴취식 수확기와 비교하여 연료가 절감되고 통마늘의 손상이 적은 장점이 있다. (중략)

• Journal of the korean Society of Automotive Engineers
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• v.16 no.6
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• pp.22-27
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• 1994

여기서는 화상처리 방법에서 화상 획득 장치와 처리 장치를 간단히 소개하고, 연료분무의 액적 운동속도의 계측 방법에 대하여 논의하기로 한다. 화사처리법은 비교적 저렴한 비용으로 정밀도 높은 정보를 프로그램에 따라 다양하게 출력하는 등의 잇점이 있다. 분무 각과 분무 관통길이도 화상 획득 장치만 기계식 스틸 카메라를 이용한 것뿐이지, 그 처리 방법은 앞서 논의한 방법과 유사하다. 1. 화상처리방법. 1.1 화상획득장치. 1.2 화상처리방법. 2. 액적크기와 운동속도. 2.1 액적크기. 2.2 운동속도.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.11a
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• pp.105-109
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• 1995

본 연구에서는 수치모사로 부터 단위 전지 양극가스내 질소 조성과 각 가스의 순환에 따른 단위전지내의 온도분포 및 성능변화를 구하였다. 양극가스내 질소의 영향은 냉각효과로 나타났고 순환비가 증가할수록 전지내의 온도와 전지의 성능은 감소하였다. 작동압력이 증가할수록 전지의 성능은 증가하였고, 기전력변화 대 압력의 상용대수변화의 직선의 기울기는 문헌상의 실험치와 유사하게 나타났다.

• Defense and Technology
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• no.5 s.267
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• pp.52-59
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• 2001

본딩은 전기/전자 시스템뿐만 아니라 연료, 엔진, 비행제어, 유/공압계통 등에서도 안전한 전기적인 운용을 하기 위해서 필요하다. 항공기 개발에서 본딩은 설계시부터 요구조건을 두어 엄격히 관리해야 하며, 제작시에도 제시된 요구조건에 맞게 본딩을 해야 한다. 항공기의 전기/전자계통 설계시 요구성능과 항공기 및 운용자의 안전성 확보를 본딩 계통의 설계목표로 설정하고, 세부적인 본딩 요구조건과 유사기종의 설계개념을 보완하여 현실적으로 적용가능한 적용분야별 본딩 설치 및 설계 요구조건을 정립하는 것이 매우 필수적이라고 판단된다. 이 글에서는 항공기 설계시 고려해야 되는 본딩 일반요구조건에 대하여 기술해 보고자 한다.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.195-196
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• 2018

제안하는 고승압 양방향 DC/DC 컨버터는 직류 탭리액터를 이용하여 인터리브드 형태와 유사한 승압형 컨버터로써 변압기 턴비를 작게 할 수 있어 고승압에 유리하다. 연료전지 응용분야에 적용가능하며 양방향제어가 가능하기 때문에 전기자동차와 같은 견인구동 응용분야에도 적용할 수 있는 장점이 있다.