• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.182-189
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• 2006

현재 반도체 습식식각 공정에 사용되고 있는 방법은 batch식과 매엽식이 있다. batch식 식각방법은 매엽식보다 throughput이 많은 반면 식각균일도는 떨어진다. 매엽식은 웨이퍼를 회전시키면서 약액을 분사할 때 Boom swing을 하여 균일하게 식각할 수 있다. 본 연구에서는 Boom swing이 없는 구조의 매엽식 장비에서 약액이 상온과 고온일 때 $SiO_2$막을 식각하여 비교하였다. 각각의 조건에서 식각량의 분포와 균일도의 변화에 대해서 알아보았으며, 실험평가시 분사된 약액의 온도분포를 이론적으로 계산하여 실제 실험결과와 비교하여 보았다. 식각균일도는 batch식 보다 매엽식 스핀방식이 균일하였으며, 약액분사 방법은 boom swing을 하는 것이 더 균일하였다.

• Clean Technology
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• v.11 no.4
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• pp.181-188
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• 2005

Developed is the new gas-solid flow ball valve where air injection purging concept is applied for the control and the reduction of particle fouling. CFD analyses are conducted for investigating the interaction between gas-sold and air injection streams and the fouling phenomena in valve, and the analysis results are reflected in the design of valve geometry and air injection condition. Through the actual tests on designed ball valve, the present valve is shown to be superior in fouling reduction.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.66-73
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• 2004

In this study, combustion characteristics and various performances of a Diesel fuel DI-HCCI engine using 2-stage injection method were investigated. From these researches, application ability of 2-stage injection strategy to a DI-HCCI engine was confirmed and improvement methods of performances were considered. As the results, Using 2-stage injection method, without change of engine specifications and loss of IMEP, exhaust of NOx and Smoke emissions could be reduced to about 1/3 (at 1400rpm, IMEP 6bar) compared to conventional Diesel combustion.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.839-841
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• 2010

기존의 범용 가솔린 소형엔진의 경우 대부분이 캬브레이터 연료 공급 방식으로 연비 및 배기가스성분이 매우 열악한 실정이다. 본 연구에서는 이러한 단점을 극복하고 배기규제에 대응하기위하여 전자제어식 연료분사방식으로 엔진을 변경하고, 관련핵심 부품의 개발을 수행하였다. 전자제어식 소형엔진에 적합한 인젝터, 연료펌프를 선정하였으며 연료레일은 새로이 설계하여 장착하였다. 최적의 작동조건을 선정하기위하여 엔진의 성능개발을 수행하였다. 개발된 소형엔진은 기존의 캬브레이터 방식의 엔진 대비 우수한 연비개선 효과와 배기가스 저감 효과가 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.353-355
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• 2008

최근 석탄 가스화 기술은 화석연료인 석탄을 기존의 공해물질 발생을 90%이상 줄이면서 고효율로 활용할 수 있는 방법으로 각광받고 있다. 본 연구는 습식 석탄 가스화기에서 가스화의 핵심적인 요소인 버너의 분무 관계 분야에 대한 분무 특성 및 무화성능을 높일 수 있는 분무기의 구조 및 운전 조건 등을 제시 할 목적으로 분무 시 내부를 관찰 할 수 있는 아크릴을 이용하여 내부 혼합식 버너를 제작하였다. 미립화 특성을 파악하기 위하여 $O_2$/Fuel Ratio 및 버너의 내부 혼합 방식, 분사각도, 각 분사 높이에 따른 미립화 특성을 관찰하였으며, 입도 분석은 심파텍사의 입도 분석기를 이용하여 측정하였다. 내부 혼합식 버너의 입도는 분사 각도와 $O_2$/Fuel Ratio에 따라서 변화하는 경향을 나타냈으며, 공급되어지는 Fuel은 석탄 슬러리와 물을 이용하여 각각의 입도를 측정하였다. slurry의 공급량이 고정된 상태에서 산소 공급량이 증가함에 따라 미립화도는 증가하는 경향을 나타내었으며, 슬러리 공급량과 산소 공급량이 동일한 경우 버너의 분사 각도에 따라 미립화도가 다르게 나타나는 특성을 관찰하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.55-62
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• 2009

As an experiment investigation, the effects of ethanol blended gasoline fuel with different injection method on nano-sized particle emission characteristics were examined in a 0.5L spark-ignited single-cylinder engine with a compression ratio of 10. Because this engine nano-particles are currently attracting interest due to its adverse health effects and their impact on the environments. So a pure gasoline and an ethanol blended gasoline fuels, namely E85 fuel, used for this study. And, as a particle measuring instrument, a fast-response particle spectrometer (DMS 500) with heated sample line was used for continuous measurement of the particle size and number distribution in the size range of 5 to 1000nm (aerodynamic diameter). As this research results, we found that the effect of ethanol blending gasoline caused drastic decrease of nano-particle emissions when port fuel injection was used for making better air-fuel mixture than direct fuel injection. Also injection timing, specially direct fuel injection, could be a dominant factor in controlling the exhaust particle emissions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.64-71
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• 2005

To achieve efficient supersonic combustion within a manageable length, a successful fuel injection scheme must provide rapid mixing between fuel and airstream. In former days, various injection concepts have been investigated. Cavity flow is the open type, that is, length-to-depth ratio L/D=4.8, aft ramp angle is $22.5^{\circ}$. An experimental study on a transverse cross jet injection into a Mach 1.92 supersonic main stream which flows over a cavity was carried out to investigate the effect of the momentum flux ratio(J), the jet interaction characteristics, and the pressure distribution in the combustor and using the primary diagnostics : schlieren visualization and wall static pressure measurements. Fuel penetration height and jet interaction characteristics depend strongly on the momentum flux ratio.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.74-77
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• 2011

A mixing characteristics on recess length change of Gas-centered swirl coaxial injector using high-performance staged combustion rocket engine carry out study through CFD(Computational fluid dynamics). propellant phase that combined gas-liquid simulate gas-gas. In order to measure spreading angle, velocity distribution to injector exit and spray structure of propellant analyzed. Axial velocity increase by increasing recess length, but tangential velocity decrease. The result confirmed qualitative characteristics that the spreading angle decreases.

• Transactions of the Korean hydrogen and new energy society
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• v.11 no.3
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• pp.107-117
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• 2000

Ball poppet valve type high pressure hydrogen injection valve actuated by solenoid has been developed for the feasibility of practical use of hydrogen fueled engine with direct injection and the precise control of fuel injection ratio in hydrogen fueled engine with dual injection. The gas-tightness of ball poppet injection valve is improved by the introduction of ball-shaped valve face, valve end typed spherical pair, and valve stem with rotating blade. Ball poppet valve is mainly closed by differential pressure due to the area difference between valve fillet and pressure piston. So, it can be operated by solenoid actuator with small driving force. From the evaluation of ball poppet injection valve, it was found that the gastightness and controlment of this injection valve are better than those of injection valve had been developed before.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1140-1147
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• 2009

Flow analyses have been performed to investigate the uniformity of propellant flow through the fuel and oxidizer manifolds of a full-scaled gas generator for a pump-fed liquid rocket engines. Injectors were simulated as porous medium layers having equivalent pressure drops. The uniformity of propellants has been analyzed for 3 fuel rings and 3 injector head configurations. The mixture ratio distribution at the exit of injectors has been estimated from the mass flow rates of fuel and oxidizer. The best configuration of fuel ring and injection head was selected through these flow analyses.