준3차원 설계법에 의한 고효율 사류팬 연구

장춘만(Choon-Man Jang),정용규(Yong-Gyu Jung),이동익(Dong-Ik Lee) 대한설비공학회 1995 대한설비공학회 학술발표대회논문집 Vol.1995 No.11

플랜트용 원심송풍기 성능평가 연구

장춘만(Choon-Man Jang),이상문(Sang-Moon Lee) 대한설비공학회 2015 대한설비공학회 학술발표대회논문집 Vol.2015 No.11

This paper presents a performance analysis of a centrifugal fan used for an automated vacuum waste collection system(AVWCS). Effects of two shapes, an inlet box and a circular curved duct between a main pipeline and a blower, is analyzed to understand the performance characteristics using experimental measurements and numerical simulation. A simulator having two centrifugal fans is introduced to analyze the effect of an inlet vane angle and an inlet box shape on the fan performance. Numerical analysis of a centrifugal blower has been carried out by solving three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. A validation of numerical results has been conducted by comparison with experimental data. Throughout experimental measurement and numerical simulation using the simulator, it is found that pressure loss due to circulation flow in the inlet box located at the upstream of the fan can be reduced by optimal shape design. Internal flow and pressure distribution along the pipeline also analyzed according to the inlet vane angles and the rotational speed of an impeller.

입구베인 각도에 따른 터보블로어 성능특성 연구

장춘만(Choon-Man Jang),임수정(Soo-Jung Lim),양상호(Sang-Ho Yang) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.3

본 연구에서는 생활폐기물 관로이송 설비에서 사용되고 있는 터보블로어 입구베인의 설정각도에 따른 성능특성을 삼차원 나비어-스톡스 방정식을 통한 수치해석과 실험적인 방법을 적용하여 분석하였다. 다양한 압력특성에 따라 운전되는 시스템 특성을 고려하여 2 대의 터보블로어를 직렬로 연결한 실험용 시뮬레이터를 설계, 제작하고 각각의 터보블로어 성능특성을 입구베인의 설정각도에 따라 분석하였다. 입구베인의 설정각도에 따른 터보블로어 성능특성을 수치해석과 실험적 평가밥법으로 분석하여, 입구베인 설정각도가 완전 개방조건인 90 도에서 60 도까지 사용하였을 경우 효율의 손실없이 압력 및 유량을 제어할 수 있음을 확인하였다. 입구베인의 설정각도가 작은 경우에는 입구측의 스월흐름으로 인하여 입구 유속분포가 불균일하게 되며, 이로 인하여 하류측에 설치되는 터보블로어의 효율이 상대적으로 감소됨을 알 수 있었다. Turbo blowers are mainly used in refuse collection systems. We discuss blower performance in relation to the angle of the inlet vane installed at the upstream of the blower. The flow characteristics of the components are analyzed by three-dimensional Navier-Stokes analysis and compared to experimental results. A two-stage serially connected turbo blower is introduced to analyze the performance experimentally. Throughout the experimental measurements and the numerical simulation, the distorted inlet velocity generated in the small vane angle reduces the performance of the blower, because of the local leading-edge separation and the resulting non-uniform blade loading. We also perform a detailed flow analysis using the results obtained in the numerical simulation.

축류 송풍기 허브측 불균일 유입유동 현상 및 성능 특성

장춘만(Choon-Man Jang),최승만(Seung-Man Choi),김광용(Kwang-Yong Kim) 한국유체기계학회 2005 유체기계 연구개발 발표회 논문집 Vol.- No.-

Performance characteristics of an axial flow fan having distorted inlet flow have been investigated using numerical analysis as well as experiment. Two kinds of hub-cap, round shape and right-angled front shape, are tested to investigate the effect of inlet flow distortion on the fan performance. In case of right-angled front shape, axisymmetric distorted inflow is induced by flow separation at the sharp edge of hub-cap, and the characteristics of the inflow depends on the distance between hub-cap and blade leading edge. Flow analysis of the blade passage is performed by solving the three-dimensional Reynolds-averaged Navier-Stokes equations. Numerical solutions are validated in comparison with experimental data measured by a five-hole probe downstream of the fan rotor. It is found from the numerical results that non-uniform axial inlet velocity profile near the hub results in the change of inlet flowangle. The changed inlet flow angle near the hub invokesa flow separation on the blade surfaces, thus deteriorating the fan efficiency. The effect of the distance between hub-cap and blade leading edge on the efficiency is also discussed.

효율 향상을 위한 축류 압축기 동익의 스윕, 린, 스큐각의 형상 최적화

장춘만(Choon-Man Jang),Abdus Samad,김광용(Kwang-Yong Kim) 한국유체기계학회 2005 유체기계 연구개발 발표회 논문집 Vol.- No.-

Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using response surface method and three-dimensional Navier-Stokes analysis. Three design variables of blade sweep, lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor, the adiabatic efficiency is increased by reducing the hub corner and tip losses. Separation line due to the interference between a passage shock and surface boundary layer on the blade suction surface is moved downstream for the optimized blade compared to the reference one.

에어콘 실외기용 축류송풍기의 비정상 유동장 특성 연구

장춘만(Choon-Man Jang) 한국유체기계학회 2005 유체기계 연구개발 발표회 논문집 Vol.- No.-

The unsteady nature of vortex structures has been investigated by a large eddy simulation (LES) in anaxial flow fan with a shroud covering only the rear region of its rotor tip. The simulation shows that the tip vortex plays a major role in the structure and unsteady behavior of the vortical flow in the fan. The movements of the vortex structures induce high-pressure fluctuations on the rotor blade and in the blade passage. Frequency characteristics of the fluctuating pressure on the rotor blade are analyzed using wavelet transform. The dominant frequency of the real-time pressure selected at the high pressure fluctuation region corresponds well to that of the fluctuating rotor torque and the experimental result of fan noise. It is mainly generated due to the unsteady behavior of the vortical flow, such as the tip vortex and the leading edge separation vortex.

평판익 후연의 형상에 따른 후류 특성

장춘만(Choon-Man Jang),Ahmad Imteyaz(Imteyaz Ahmad),김광용(Kwang-Yong Kim) 한국유체기계학회 2004 유체기계 연구개발 발표회 논문집 Vol.- No.-

The influence of wake flow on a flat-plate blade having different shapes near the trailing edge has been investigated in this paper. Two different shapes near the trailing edge namely the pressure surface cutting (TP) and the suction surface cutting (TS) have been used. The calculation has been performed for two different angles of attack (a =10 and 15 degree) in both the cases. RANS equations have been solved using SST-model as a turbulence closure. Cp and CL values obtained for TS are higher compared to those obtained for TP. Also, the vorticity distribution obtained in case of TS is stronger as compared to that obtained in the case of TP. The Karmann Vortex is observed in both the cases but it is more clear in TS case. It is found that in the case of TS, flow separation does not occur upto the trailing edge on both the suction and the pressure sides of the blade while in the case of TP, the flow separateson the pressure surface near the trailing edge of the flat-plate blade.

축류압축기 동익의 스윕각 최적화

장춘만(Choon-Man Jang),Li Ping(Ping Li),김광용(Kwang-Yong Kim) 한국유체기계학회 2004 유체기계 연구개발 발표회 논문집 Vol.- No.-

The optimization of a blade sweep for a transonic axial compressor rotor (NASA rotor 37) has been performed using a response surface method and a Reynolds-averaged Navier-Stokes (HANS) flow simulation. Two shape variables of the rotor blade, which are used to define a blade sweep, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. The result shows that the adiabatic efficiency is increased to about 1 percent compared to that of the reference shape of the rotor blade. Relatively high increasement of the adiabatic efficiency is obtained between 20 and 60 percent span. In the present study, backward swept blade is more effective to increase the adiabatic efficiency in the axial compressor rotor.

볼류트 케이싱 형상에 따른 터보블로어 성능특성 고찰

장춘만(Choon Man Jang),양상호(Sang Ho Yang) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.4

본 연구에서는 생활폐기물 관로이송 설비에서 사용되고 있는 터보블로어의 성능향상을 목적으로 하며, 볼류트 케이싱의 확대반경과 폭을 설계변수로 하여 삼차원 나비어-스톡스 방정식을 통한 수치해석 방법을 적용하였다. 생활폐기물 관로이송 설비에 이용되는 터보블로어는 높은 토출압력을 갖는 블로어의 설계가 요구되고 있다. 본 볼류트 케이싱 형상특성 연구를 통하여, 효율은 3%, 압력은 2% 개선되는 효과를 보았다. 이는 Cutoff 근방 및 케이싱 출구측의 부분적인 역류의 개선을 가져왔으며, 적절한 임펠러 및 케이싱의 간격유지로 Cuttoff 하류측의 압력변동이 완화됨으로써 케이싱에 따른 점진적인 압력상승이 가능하다. 수치해석을 통한 터보블로어의 내부유동장 특성을 비교하여 분석하였다. This paper describes performance characteristics of a turbo blower according to the shape of a volute casing. The turbo blower considered in a present study has a backward blade type, and is mainly used in a refuse collecting system. The flow characteristics inside the components are analyzed by three-dimensional Navier-Stokes analysis, and also compared to the results obtained by experiments. Distributions of pressure and efficiency obtained by numerical simulation have a good agreement with the experimental results. Throughout the numerical simulation of the turbo blower, a blower performance is increased by decreasing local losses in the blade passage and outlet flow. The efficiency and pressure at the design flow condition is enhanced by 3% and 2% based on the reference blower, respectively. Detailed flow analysis is also analyzed and discussed using the results obtained by numerical simulation.

스프리트 부착 원심송풍기 성능특성 연구

장춘만(Choon Man Jang),최가람(Ka Ram Choi),양상호(Sang Ho Yang) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.4

본 연구에서는 생활폐기물 관로이송 설비에서 사용되고 있는 원심송풍기의 성능향상을 위해 임펠러 날개 압력면과 부압면 측에 스프리터를 각각 장착하고, 스프리터의 코드길이 변화에 따른 성능특성을 삼차원 나비어-스톡스 방정식을 통한 수치해석과 실험적인 방법을 적용하여 분석하였다. 스프리터에 의한 날개 수 증가를 고려하여 기존 송풍기의 11개 날개를 7개로 줄이고, 날개의 회전방향으로 2개의 스프리터를 균등하게 설치하였다. 실험 및 삼차원 수치해석에 의한 분석을 통하여 날개 부압면측에서 발생하는 역류현상을 억제할 수 있는 스프리터를 설치하고 코드길이를 변수로 설정하여 분석하였다. 이를 통해 스프리터의 코드길이가 길어질수록 원심송풍기 압력 및 효율특성이 설계유량 조건 뿐만 아니라 유량증가에 따라 향상됨을 확인하였다. 설계유량을 기준으로 스프리터 부착 원심송풍기에 의해 효율 및 압력은 기존대비 각각 4% 및 18% 향상됨을 알 수 있었다. This paper describes centrifugal fan performance, which is mainly used in refuse collection system, according to the splitters installed near the suction and pressure surface side. The flow characteristics inside the components are analyzed by three-dimensional Navier-Stokes analysis, and also compared to the results obtained by experiments. Throughout the experimental measurements and numerical simulation of the fan having splitters, it is found that the reverse flow region observed near the suction side of the blade can be reduced by installing a splitter. Fan performance is successfully increased by controlling the chord length of the splitter installed near the blade suction side. At the design flow condition, efficiency and pressure of the fan having splitters increase up to 4% and 18% compared to reference fan, respectively.