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스마트 무인기 연료계통 제트펌프 설계 및 성능예측에 관한 연구
이윤권(Yoonkwon Lee),박설혜(Sulhye Park),이지근(Jeekeun Lee),이창호(Changho Lee),최희주(Heeju Choi),이수철(Soochul Lee),정재헌(Jeahun Jeong) 한국자동차공학회 2007 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-
This paper is concerned with the design and performance prediction of jet pumps for fuel system. The jet pump is important component to transfer the fuel between tanks in fuel supply system. However detailed design procedures for sizing the component of the jet pumps are known a little. In this paper the jet pump was designed according to the design procedure based on the theoretical analysis. For verifying the design results from the theoretical approach, the performance of the designed jet pump was predicted using a commercial analysis code and was verified through the experiment for the jet pump sizing with high performance. The flow ratio and pressure ratio were compared with target value and satisfied the demands in fuel supply system. Further research was carried out to obtain more conclusive information from various interference conditions and for improvement in performance.
스마트무인기 연료시스템 연료이송 제트펌프의 성능평가에 관한 실험적 연구
이윤권(Yoonkwon Lee),김의수(Euisoo Kim),박설혜(Sulhye Park),이지근(Jeekeun Lee),이창호(Changho Lee),이수철(Soochul Lee),최희주(Heejoo Choi) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.12
스마트무인기 연료공급시스템에 사용되는 제트펌프의 연료탱크 사이의 연료이송 특성이 실험적으로 조사되었다. 제트펌프의 작동조건은 비행체의 임무에 따른 엔진의 요구사항을 만족하도록 설정되었으며, 주어진 조건에서 제트펌프의 성능을 평가하였다. 제트펌프의 유량비 변화에 따른 압력비 및 효율이 측정되었으며 면적비 변화 등이 고려되었다. 평가 결과로부터 제트펌프는 주어진 압력비보다 큰 범위에서 작동목표인 유량비 2.23을 만족하였다. 효율보다 연료공급량이 중시되는 연료이송 제트펌프의 경우 면적비 변화를 통하여 허용 압력비 범위 내에서 유량비 조절이 가능함을 알 수 있었다. The fuel transfer characteristics of the jet pump between fuel tanks, which is applied in the smart UAV fuel supply system, were experimentally investigated. The operating conditions of the jet pump were setup to meet the engine requirement according to mission profile, and the jet pump performance was evaluated at those conditions. The pressure ratio and the efficiency of the jet pump were measured with the variation of flow ratio. In addition, the area ratio was taken into the consideration to examine the effect on the jet pump performance. From the evaluation results, the jet pump met the fundamental requirement to transfer fuel with the flow ratio of 2.23. In the case of the jet pump that is focused on the fuel transfer quantity rather than its efficiency, the flow ratio would be adjusted through the variation of area ratio of the jet pump within the permitted limit of pressure ratio.
Jeekeun LEE,Byungjoon RHO,Kyukeun SONG,Jaeyoun JUNG,Keiya NISHIDA 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.10
The spray and ambient air motions produced by a swirl-type D.I. gasoline injector were simultaneously measured by combining the laser induced fluorescence and the particle image velocimetry (LIF-PIV) techniques. For the simultaneous measurement of the fuel spray and the ambient air velocities, the succeeding two image pairs of the spray and the ambient air tracer particle were captured by using two high-resolution CCD cameras. The images acquired were analyzed by the double frame cross-correlation PIV technique, and the droplets and ambient air velocity distributions were obtained. Furthermore, distributions of relative velocities between the droplets and ambient air in the spray were analyzed.
Effect of Reynolds Numbers on Counter-rotating Swirling Flow in a Model Gas Turbine Combustor
Sangho Lee(이상호),Yuin Jin(진유인),Gyongwon Ryu(유경원),Jeekeun Lee(이지근) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11
The characteristics of swirling flow in a model gas turbine combustor, which is one of the most important phenomenon for efficiency and flame stabilization in gas turbines, were studied in the paper. The gas turbine combustor was modeled as rectangular shape to examine the swirling flow generated by swirler for the experiment. The model combustor consists of counter-rotating axial swirler to generate the swirling flow. A PIV system was used to measure velocity components of the swirling flow. Additionally, the mean and turbulent components were discussed which were calculated by averaging the acquired many seeding particle images. The pure water was used as a working fluid. The characteristics of swirling flow, including the formation of a central recirculation zone, corner vortex, and the wall flow along the model combustor wall, were mainly discussed and investigated with Reynolds numbers.
밸브 닫힘각 변화에 따른 버터플라이밸브의 손실계수 평가
이지근(Jeekeun Lee),노병준(Byungjoon Rho),최희주(Heejoo Choi) 한국항공우주학회 2008 韓國航空宇宙學會誌 Vol.36 No.1
밸브 디스크 직경이 25.4 ㎜ 인 소형 버터플라이밸브의 유동특성이 다양한 밸브 닫힘각에 대해 실험적으로 연구되었다. 밸브 디스크각이 작은 경우 유량조절특성을 향상시키기 위해 주어지는 밸브 닫힘각을 0°, 5°, 10°, 20°, 30°로 변화시켜 밸브 디스크각에 따른 손실계수를 측정하였다. 또한 밸브선단 형상이 손실계수 변화에 미치는 영향을 조사하였다. 밸브 닫힘각이 증가함에 따라 최대손실계수는 감소하며, 밸브 닫힘각 0°~5°에서 가장 큰 감소를 나타냄을 알 수 있었다. 밸브 디스크 형상에 따른 손실계수는 밸브 닫힘각이 0°인 경우 날카로운 모서리를 갖는 디스크가 더 큰 손실계수를 나타낸 반면, 닫힘각 10°의 경우 날카로운 모서리를 갖는 디스크의 경우가 더 낮은 손실계수를 나타냄을 알 수 있었다. In this study, flow characteristics of a small-sized butterfly valve with the valve disk diameter of 25.4 ㎜ have been investigated experimentally for the valve closed angles. In order to examine the flow characteristics of the butterfly valve, loss coefficient (K<SUB>v</SUB>) was obtained at the valve closed angles of 0°, 5°, 10°, 20° and 30°. In addition, the effects of the valve disk edge shape were examined. As the result of the experiment, the maximum loss coefficient (K<SUB>vmax</SUB>) was decreased with the increase of the valve closed angle, and it had the maximum decrease ratio at the valve disk angles of 0°~5°. The valve disk edge shape have an effect on the loss coefficient of the valve around the small valve closed angle.
Sangkyoo Lee,Namsoo Moon,Jeekeun Lee 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.9
A multi-perforated tube indicates the existence of multiple holes in various shapes on the surface of long cylinder-type or rectangular tubes, and the hole installed on the surface is called an orifice as it is relatively small in size, compared with the surface area of the tubes. In this study, flowrate distribution features and changes in discharge angle according to the blockage ratio resulting from the changes in the number of orifices and the thickness of multi-perforated tubes were investigated by means of analysis and experiment, targeting the multi-perforated tubes where rectangular orifices are installed on the both sides of square tubes. In addition, contraction coefficient and flow coefficient between orifices were analytically investigated. The more increase in blockage ratio of multi-perforated tubes, the more uniform flowrate distribution between orifices. The discharge angle becomes more and more perpendicular in the longitudinal direction of multi-perforated tubes as it gets closer to the end of orifices, exhibiting big differences at the entrance if blockage ratio is small. The more increase in the thickness of multi-perforated tubes, the more uniform flowrate distribution between orifices become as contraction coefficient increases. The flow coefficient distribution of orifices using the pressure at the entrance of the orifices of multi-perforated tubes increases in the longitudinal direction of the multi-perforated tubes, exhibiting values ranging from 0.66 to 0.68 as to BR = 0.893 ~0.979.
덕트 내 오염물질 퇴적 방지를 위한 벽면유동 제어에 관한 해석적 연구
이방욱(Banguk Lee),이지근(Jeekeun Lee) 대한설비공학회 2013 설비공학 논문집 Vol.25 No.5
Technologies for preventing contaminants deposition are a key issue in a modern duct system. When particulate matters deposit inside the exhaust pipes, which are widely used in the Urea-SCR system to reduce NOx emission from heavy duty diesel engines, many problems arise associated with increased flow resistance and corrosion. Therefore, the development of the urea deposition avoidance technologies is being treated as an important issue of the Urea-SCR system. An analytical study was carried out to investigate the effects of the wall flow around the mixer with the variation of the mixer housing surrounding and supporting the mixer, which is designed to increase the wall flow and then to reduce droplet deposition. The housing angles and the position of the mixer were changed:angles of 0°, 1° , 2° , and 3° , and mixer positions of 0 L, 0.5 L, and 1 L. The axial velocity distributions, maximum velocity, the half-width, and momentum distribution of the wall flow were investigated to examine the effect of the mixer-housing assembly geometry.
모형 가스터빈 연소기 내 Counter-rotating 선회유동에 관한 실험적 연구
이상호(Sangho Lee),진유인(Yuin Jin),민성기(Sungki Min),이지근(Jeekeun Lee) 한국추진공학회 2014 한국추진공학회 학술대회논문집 Vol.2014 No.12
가스 터빈의 효율을 결정하는 여러 요인들 중, 스월러가 일으키는 선회 유동은 혼합기와 화염의 안정화에 지대한 영향을 미친다. 본 연구에서는 가스 터빈의 연소실 내에서 스월러에 의해 일어나는 선회 유동에 대해 고찰하였다. 스월러에 부착된 플레어의 유무에 따른 유동을 비교 분석하였고, 플레어가 유동에 미치는 영향을 가시화하기 위하여 PIV 기법을 사용하였다. 작동 유체로는 물을 사용했으며, 축방향 속도, CRZ (Central Recirculation Zone) 를 분석하여 플레어가 존재함으로 인해서 재순환 영역이 더욱 크게 형성된다는 것을 확인하였다. One of the factor which determines the efficiency of gas turbines, the swirling flow caused by swirler affects the mixing gas and flame stabilization. In this sutdy, swirling flow in the gas turbine combustor was investigated experimentally. Swirling flow was analyzed and compared to the flow with and without swirler flare. PIV was used to visualize the effect of flare to the flow. Water was used as the fluid. This study confirmed that recirculation zone is larger with swirler flare by analyzing axial velocity profiles and CRZs.