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5공 피토관 및 회전 열선 유속계에 의한 축류 홴 내부 유동장 계측 및 평가
장춘만,김광용,Jang, Choon-Man,Kim, Kwang-Yong 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.12
This paper describes the flow measurements inside the blade passage of an axial flow fan by using a rotating hot-wire probe sensor from a relative flame of reference fixed to the rotor blades. The validity of fan rotor designed by a streamline curvature equation was performed by the measurement of the three-dimensional flow upstream and downstream of the fan rotor using a 5-hole pitot tube. The vortical flow structure near the rotor tip can be clearly observed by the measurements of a relative velocity and its fluctuation on quasi-orthogonal planes to a tip leakage vortex. Larger vortical flow, which results in higher blockage in the main flow, is formed according to decrease a flow rate. The vortical flow spreads out to the 30 percent span from the rotor tip at near stall condition. In the design operating condition, the tip leakage vortex is moved downstream while the center of the vortex keeps constant in the spanwise direction. Detailed characteristics of a velocity fluctuation with relation to the vortex were also analyzed.
장춘만,이상문,전완호,임태균 한국수소및신에너지학회 2014 한국수소 및 신에너지학회논문집 Vol.25 No.6
This paper presents annual energy production (AEP) by a 1.5kW wind turbine due to be installedin Deokjeok-Do island. Local wind data is determined by geometric shape of Deokjeok-Do island and annual winddata from Korea Institute of Energy Research at three places considered to be installed the wind turbine. Numericalsimulation using WindSim is performed to obtain flow pattern for the whole island. The length of each computationgrid is 40 m, and k-e turbulence model is imposed. AEP is determined by the power curve of the wind turbineand the local wind data obtained from numerical simulation. To capture the more detailed flow pattern at thespecific local region, Urumsil-maul inside the island, fine mesh having the grid length of 10m is evaluated. Itis noted that the input data for numerical simulation to the local region is used the wind data obtained by thenumerical results for the whole island. From the numerical analysis, it is found that a local AEP at the Urumsil-maulhas almost same value of 1.72 MWh regardless the grid resolutions used in the present calculation. It is notedthat relatively fine mesh used for local region is effective to understand the flow pattern clearly.
장춘만,이종성,전완호,임태균 한국수소및신에너지학회 2013 한국수소 및 신에너지학회논문집 Vol.24 No.6
This paper presents how to determine AEP(Annual Energy Production) by a small wind turbine in DuckjeokDo island. Evaluation of AEP is introduced to make a self-contained island including renewable energy sources of wind, solar, and tidal energy. To determine the AEP in DuckjeokDo island, a local wind data is analyzed using the annual wind data from Korea Institute of Energy Research firstly. After the wind data is separated in 12-direction, a mean wind speed at each direction is determined. And then, a small wind turbine power curve is selected by introducing the capacity of a small wind turbine and the energy production of the wind turbine according to each wind direction. Finally, total annual wind energy production for each small wind turbine can be evaluated using the local wind density and local energy production considering a mechanical energy loss. Throughout the analytic study, it is found that the AEP of DuckjeokDo island is about 2.02MWh/y and 3.47MWh/y per a 1kW small wind turbine installed at the altitude of 10 m and 21m, respectively.
Performance Enhancement of 20kW Regenerative Blower Using Design Parameters
장춘만,전현준 한국유체기계학회 2014 International journal of fluid machinery and syste Vol.7 No.3
This paper describes performance enhancement of a regenerative blower used for a 20 kW fuel cell system. Two design variables, bending angle of an impeller and blade thickness of an impeller tip, which are used to define an impeller shape, are introduced to enhance the blower performance. Internal flow of the regenerative blower has been analyzed with threedimensional Navier-Stokes equations to obtain the blower performance. General analysis code, CFX, is introduced in the present work. SST turbulence model is employed to estimate the eddy viscosity. Throughout the numerical analysis, it is found that the thickness of impeller tip is effective to increase the blower efficiency in the present blower. Pressure is successfully increased up to 2.8% compared to the reference blower at the design flow condition. And efficiency is also enhanced up to 2.98 % compared to the reference one. It is noted that low velocity region disturbs to make strong recirculation flow inside the blade passages, thus increases local pressure loss. Detailed flow field inside the regenerative blower is also analyzed and compared.