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조이상(Leesang Cho),이세욱(Seawook Lee),조진수(Jinsoo Cho) 한국항공우주학회 2010 韓國航空宇宙學會誌 Vol.38 No.10
초소형 무인기 추진용 MH-75 프로펠러는 자유와 설계기법을 이용하여 설계변수인 허브팁 비, 비틀림각 분포, 최대 캠버의 위치와 크기 그리고 시위 길이를 변화시키며 설계 요구조건을 만족하도록 공력설계 되었다. MH-75 프로펠러는 주파수영역 패널법을 이용하여 설계요구조건을 만족시키고, 다양한 초소형 무인기에 적용이 가능하도록 정지추력 특성과 비행속도 및 회전수 변화에 따른 성능 특성을 예측하였다. 그리고 MH-75 프로펠러의 공력해석 결과를 검증하기 위해 프로펠러의 추력특성에 대한 풍동시험을 수행하였다. MH-75 프로펠러의 추력 성능은 설계요구조건을 만족하였으며, 저레이놀즈 수 영향을 고려하기 위한 2차원 익형 해석용 XFOIL 프로그램에 비해 3차원 효과를 고려하는 주파수영역 패널법을 이용하는 것이 비교적 풍동시험 결과와의 오차가 적음을 확인하였다. The MH-75 propeller for the MAV propulsion is designed using a free vortex design method which considers design parameters such as the hub-tip ratio, the twist angle distribution, the maximum camber location and the chord length of the propeller blade. Aerodynamic characteristics of the MH-75 propeller are predicted by changing the flight speed using the frequency domain panel method. And, the thrust characteristics of the MH-75 propeller are measured using the balance system of the subsonic wind tunnel for the validation of numerical results. The performance characteristics of the MH-75 propeller satisfied with design requirements. Numerical results of the MH-75, which are predicted by the frequency domain panel method, are more agree with experimental results compare with XFOIL.
조이상(LeeSang Cho),신동민(Dongmin Shin),천승태(Seungtae Chun) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11
The combination of Internet of Things and Big data in the shipbuilding industry can be used in various processes and facilities. Especially in Korea, although many shipyards collect and integrate data in real time, it is difficult to find actual use cases. In addition, efficient analysis is also difficult since data collection and analysis is performed through multiple platforms. In this study, it is expected that the analysis result can be applied in the overall field of shipbuilding marine industry by constructing an integrated platform that can receive and analyze the various equipments and worker’s data used by shipyards through IoT devices.
축류식 In-ling duct fan의 공력특성에 관한 전산해석
조이상(Leesang Cho),안광원(Kwangweon Ahn),조진수(Jinsoo Cho) 한국항공우주학회 2004 韓國航空宇宙學會誌 Vol.32 No.4
축류식 인라인 덕트팬의 개발을 위해 엇회전식 축류팬의 공력 특성에 관한 수치해석을 수행하였다. 기존의 동익과 정익으로 구성된 축류팬의 설계기법을 확장하여, 서로 반대방향으로 회전하는 전단 동익과 후단 동익의 블레이드 형상을 설계하였다. 그리고, 압축기나 터빈 등의 터보기계 관통 유통 해석 기법인 행렬법을 엇회전식 축류팬에 적용하였고, 주파수영역 패널법을 확장하여 엇회전식 축류팬의 공력 해석 및 성능 예측을 수행하였다. 엇회전식 축류팬의 관통 유동 해석 결과, 전단 동익과 후단 동익의 허브 부분에서 많은 유동 손실이 발생했다. 그리고, 주파수 영역 패널법을 이용한 공력 해석을 통해 블레이드의 유통손실이 주로 블레이드 전연에서 나타남을 알 수 있었고 성능 특성이 약간 과도하게 예측되었다. Numerical analyses on the aerodynamic characteristics of a counter rotating axial flow fan were conducted for the development of an axial type in-line duct fan The counter rotating fan has a front rotor and a rear rotor which are counter rotating each other. Blade design of the counter rotating fan was done by extension of design method for axial flow fan which consists of rotor and stator blades. Through flow analysis was performed using matrix method which is applied for flow fields prediction of compressors or turbines. Aerodynamic characteristics and characteristic curves of the counter rotating fan were analyzed by expansion of the frequency domain panel method with duct modeling. Pressure losses were higher at leading edge and hub region of rotor blades. Characteristic curve of the counter rotating fan was overpredicted without consideration of viscous effect.
조이상,조진수,Cho, Leesang,Cho, Jinsoo 한국교통대학교 융복합기술연구소 2015 융ㆍ복합기술연구소 논문집 Vol.5 No.1
Numerical analyses on the aerodynamic characteristics of a counter rotating axial flow fan is carried out using the frequency domain panel method. Front rotor and rear rotor blades of a counter rotating axial fan are designed by using the simplified meridional flow analysis method with the radial equilibrium equation and the free vortex design condition, according to design requirements. Performance characteristics of a counter rotating axial flow fan are estimated for the variation of design parameters such as the hub to tip ratio, the taper ratio and the solidity. Pressure losses were higher at leading edge and hub region of rotor blades. Characteristic curve of the counter rotating fan was overpredicted without consideration of viscous effect.
고성능 2단 축류송풍기의 공력설계를 위한 수치해석 및 실험에 관한 연구
조진수,한철희,조이상,Cho, Jinsoo,Han, Cheolhui,Cho, Leesang 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.8
A numerical method and experiments for the aerodynamic design of high performance two-stage axial flow fans was carried out. A vortex ring element method used for the aerodynamic analysis of the propellers was extended to the fan-duct system. Fan Performance and velocity profiles at the fan inlet and outlet are compared with experimental data for the validations of numerical method. Performance test was done based on KS B 6311(testing methods for turbo-fans and blowers). The velocity profile was obtained using a 5-hole pitot tube by the non-nulling method. The two stage axial flow fan configurations for the optimal operation conditions were set by using the experimental results for the single rotating axial flow fan and the single stage axial flow fan. The single rotating axial flow fan showed relatively low efficiency due to the swirl velocities behind rotor exit which produced pressure losses. In contrast, the single stage and the two-stage axial flow fans showed performance improvements due to the swirl velocity reduction by the stator. The peak efficiency of the two stage axial flow fan was improved by 21% and 6%, compared to the single rotating axial flow fan and the single stage axial flow fan, respectively.
덕티드 팬 무인기의 동익과 정익 공력상호작용에 대한 실험적 연구
류민형(Minhyoung Ryu),조이상(Leesang Cho),조진수(Jinsoo Cho) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.11
소형 무인항공기 추진용 덕티드 팬의 실험적 연구가 수행되었다. 이 논문에서는 덕티드 팬의 입구, 로터 뒤, 스테이터 뒤에서 허브에서 팁 방향으로 45° 경사 열선으로 측정하여 비정상 3차원 유동 특성을 연구하였다. 경사열선 요각을 고정시켜 데이터를 획득하였다. 이 데이터는 위상평균기법을 이용하여 평균되었다. 이 데이터는 Newton-Rhapson 수치해법을 통하여 3개의 비선형 연립방정식을 풀었다. 축 방향, 반경 방향 그리고 원주 방향 속도의 윤곽을 통해 팁 후류, 이차유동 그리고 팁 누설유동과 같은 유동 특성을 확인 하였다. The experimental study on the ducted fan for the propulsion system of a small UAV has been performed. In this paper, to investigate the three-dimensional unsteady flow field characteristics of the ducted fan, it was measured by using a 45° inclined hot-wire from hub to tip at inlet, behind the rotor and outlet of the ducted fan. The hot-wire signal data was acquired at fixed yaw angle. The data was averaged by using the PLEAT (Phase Locked Ensemble Averaging Technique), and then three of non-linear equations were solved simultaneously by using the Newton-Rhapson numerical method. Flow characteristics such as tip vortex, secondary flow and tip leakage flow were confirmed through axial, radial and tangential contour plot.
엇회전식 축류팬의 작동조건 변화에 따른 비정상 유동에 관한 실험적 연구
강현구(Hyunkoo Kang),조이상(Leesang Cho),조진수(Jinsoo Cho) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11
Experiments were done for the unsteady flow in a counter rotating axial flow fan near peak efficiency and stall point. Flow fields in a counter rotating axial flow fan were measured at cross-sectional planes of the upstream and downstream of each rotor. Cross sectional passage flow patterns were investigated through the acquired data by the 45° inclined hot-wire. Comparison of flow characteristics between two different operating conditions such as tip vortex, secondary flow and turbulence intensity were performed through the analyses of axial, radial and tangential velocity distributions. As a result, tip vortex and secondary flows are enforced and measured obviously at stall point.
엇회전식 축류팬의 3차원 비종상 유동에 관한 실험적 연구
박현수(Hyunsoo Park),조이상(Leesang Cho),강현구(Hyunkoo Kang),조진수(Jinsoo Cho) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11
Experiments were done for the three dimensional unsteady flow in a counter rotating axial flow fan under<br/> stable operating condition. Flow fields in a counter rotating axial flow fan were measured at cross-sectional<br/> planes of the upstream and downstream of each rotor. Cross sectional flow patterns were investigated through<br/> the acquired data by the 45° inclined hot-wire. Flow characteristics such as tip vortex, secondary flow and tip<br/> leakage flow were confirmed through axial, radial and tangential velocity vector plot. Swirl velocity, which<br/> was generated by the front rotor, was recovered in the form of static pressure rise by the rear rotor except for<br/> hub and tip regions.