• 한국군사과학기술학회지
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• 제6권4호
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• pp.113-123
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• 2003

Both numerical analysis and experiment of cold and hot tests were performed to obtain basic design data for the swirl coaxial type Injector and to predict the combustion performance. Mass distribution, mixing distribution, mixing efficiency, characteristic velocity efficiency were measured by the cold tests and numerical analysis using the commercial thermo-hydraulic program. Test and analysis variables were recess, pressure drop, velocity ratio, mixing spray, mixture ratio. Hot tests were performed for the Uni-element injector to compare the performance with the cold test results, and, hot tests for Multi-element injector were performed to compare the performance with Uni-element injector. Designed thrust of the Uni-element injector liquid rocket was 35kgf at sea level and combustion chamber pressure, 20bar. Kerosene and Lox were used as a propellant.

• 청정기술
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• 제30권2호
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• pp.94-104
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• 2024

재제조는 사용 후 제품을 분해, 세척, 검사, 보수, 조정, 재조립하여 원래의 성능 또는 그 이상의 성능을 가진 제품으로 재상품화하는 것으로, 재제조산업은 2050 탄소중립을 실현하기 위해 필요한 핵심 산업이다. 본 연구에서는 자동차부품 중 재제조가 활발히 이루어지고 있는 인젝터를 대상으로 전과정평가를 이용하여 회피효과를 고려 시와 미고려 시 자원 저감 및 온실가스 저감 효과를 분석하고자 한다. 연구결과, 인젝터 재제조로 인한 자원 저감 효과와 온실가스 저감 효과는 회피효과를 미고려 시 1개 기준으로 95.30%, 93.88%가 저감되는 것으로 나타났다. 재제조 시 제품을 재사용함으로써 사용 후 제품이 폐기되지 않는 환경영향과 천연자원을 사용하지 않는 환경영향의 회피효과를 고려할 시 190.91%, 188.33%가 저감되는 것으로 나타났다. 본 연구결과는 향후 재제조 시 회피효과를 고려한 환경영향 저감량을 평가하고, 연구방법론 개발 시 활용할 수 있을 것으로 본다.

• 한국군사과학기술학회지
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• 제6권4호
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• pp.132-144
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• 2003

Numerical analysis of the spray angles of Dual swirl injector were investigated to obtain basic design data and to predict the combustion performance. Using the commercial thermal hydraulic program, discharge coefficients and spray angles were numerically analyzed with recess length, pressure drop, velocity ratio, mixture ratio and back hole length. Water was used as simulants for oxidizer and fuel, respectively to compare the experimental results. Swirl injectors were designed to inject oxidizer of 70.5g/s and fuel of 29.5g/s at the pressure drop of 1MPa and two recess lengths were considered. In addition, the effect of injector geometry coefficient and velocity ratio on the discharge coefficient was studied.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.892-895
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• 2017

대형 가스터빈 연소기 구성품인 단일 압력선회식 연료분사기(Pressure swirl simplex liquid injector)를 설계, 분무특성 및 성능을 시험을 통해 평가하였다. 공급 압력 대비 분무 유량을 측정하여 설계점 기준 분무유량과 비교하였으며 섀도우그래프(Shadowgraph)를 통해 분무가시화이미지를 기록, 분무의 형상을 정성적으로 파악하고 분무각을 측정하였다. 시험 결과 동일한 공급압력 대비 측정된 분무유량은 설계점 기준 유량과 거의 일치하여 설계 및 제작의 정합성이 확인되었으며 섀도우그래프 이미지를 통해 연료분사기의 분무형상을 파악하고 설계 의도된 분무각이 나타남을 확인할 수 있었다. 이를 기반으로 향후 PDA(Phase Doppler Anemometry)를 통한 분무측정을 통해 보다 구체적인 연료 분사기의 분무 성능 및 특성을 파악할 수 있을 것으로 기대된다.

• Journal of Multimedia Information System
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• 제7권2호
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• pp.175-188
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• 2020

The paper focuses on conception and development of complex systems composed mainly by a pump syringe subsystem and an electronically injector that facilitates patients saving data operation for medical staff use. We successfully developed conventional approaches for medical system staff requirements, such as system boundary conditions. Decisions at a given level are studied. We propose a complex system architecture, based mainly on patients collected data and ordered stepper injection parameters. System is successfully simulated and prototyped. Design and implement tests are accomplished, the proposed system ensures both the electric syringe pump and the electric injector operation. In addition, this new system introduces several additional options as patient database development and automation injection operation. Development and software operating tests to create a visualization control interface are validated. The solution performs syringe function and electronic injector. User can manage a syringe in two C modes of technology. We propose a program composed of two linked parts. If an error such radiologist bad target selection is made, an image with lower intrinsic quality emerges. Developed Shoot syringe different electronic cards are simulated and prototyped, in addition, maps are driven, prototype. All tests results are accomplished.

• 한국연소학회지
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• 제5권1호
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• pp.43-53
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• 2000

Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignition process with liquid rocket engine. The propellant used is a Jet A-1 as fuel and a liquid oxygen as oxidizer. Unlike impinging FOOF type of injectors are arranged radially and the designed O/F ratio is 2.34. The present experiment program also includes the stability on the quadlet type of ignitor using the triethylalumimum as an ignition source and injector life tests. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time of propellants affects the engine performance little. The effect of positioning cooling holes is remarkable to protect the injector face.

• 한국항공우주학회지
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• 제48권9호
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• pp.703-709
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• 2020

핀틀 인젝터는 LMDE의 인젝터로 채용되어 아폴로 계획의 성공적인 수행에 일조하였으며, 최근 SpaceX 사의 Merlin 엔진으로 다시 조명받고 있는 인젝터의 형태이다. 본 연구에서는 액체산소/기체메탄을 이용하는 500N 급 Lab-Scale 핀틀 인젝터 추력기를 제작하여 연소실험을 수행하였다. 그러나 초기 연소실험은 핀틀 팁의 용융과 낮은 연소효율이라는 문제를 노출하였다. 따라서 이를 해결하기 위하여 전산수치해석을 통한 시뮬레이션을 통해 유동 가이드가 추가된 핀틀 팁의 냉각 성능을 향상시킬 수 있는 설계를 채택하였으며, 연소실험을 통해 유동 가이드의 효용성을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.699-703
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• 2017

액체로켓엔진에 사용되는 동축 와류형 분사기의 유동특성을 알아보기 위해 closed-type과 open-type 단일 분사기에 대한 수치해석을 수행하였다. ANSYS FLUENT라는 상용프로그램을 이용하여 해석적인 연구를 수행하였다. 분사기는 리세스 길이가 다른 3개의 모델을 선정하였다. 분사기 접선 방향의 입구로 유입되는 질량유량에 따라서 분사기 유동특성이 어떻게 변하는지 알아보기 위하여 수치해석을 수행하였으며, 실험을 통해 측정된 결과를 비교 및 분석하였다. 수치해석을 통해 얻은 결과는 실험을 통해 얻은 분사기 전단에 작용하는 압력과 유량계수와 차이가 크지 않음을 알 수 있었다.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.116-122
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• 2012

The purpose of this study is to investigate the overall spray behavior characteristics for various injection conditions in a gasoline direct injection(GDI) injector with multi-hole. The spray characteristics, such as the spray penetration, the spray angle, and the injection quantity, were studied through the change of the injection pressure, the ambient pressure, and the energizing duration in a high-pressure chamber with a constant volume. The n-heptane with 99.5% purity was used as the test fuel. In a constant volume chamber, the injected spray was visualized by the spray visualization system, which consisted of the high-speed camera, the metal-halide lamp, the injector control device, and the image analysis system with the image processing program. It was revealed that the injection quantity was mainly affected by the difference between the injection pressure and the ambient pressure. For low injection pressure conditions, the injection quantity was decreased by the increase of the ambient pressure, while it nearly maintained regardless of the ambient pressure at high injection pressure. According to the increase of the ambient pressure in the constant volume chamber, the spray development became slow, consequently, the spray tip penetration decreased, and the spray area increased. In additions, the circular cone area decreased, and the vortex area increased.

• ETRI Journal
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• 제26권2호
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• pp.149-160
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• 2004

In this paper, we present an interactive data broadcasting system compliant with the Advanced Television Systems Committee (ATSC) standards. The proposed system provides users not only with various data broadcasting services but also remote interactive services. For various data broadcasting services, we have adopted a synchronized data injector that calculates the transmission time of synchronized data accurately and multiplexes synchronized data with the data of an MPEG-2 audio-visual program according to the calculated transmission time. To support remote interactive services, we designed and implemented a return channel server connected on a bi-directional interaction channel. Test results show that the proposed system provides both an asynchronous and synchronized data broadcasting service and remote interactive service appropriately.