• 한국항공운항학회지
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• 제19권4호
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• pp.24-29
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• 2011

Conceptual study of an open-circuit type low-speed wind tunnel for performance test of wind turbine blade and airfoil is conducted. The tunnel is constituted of a settling chamber, a contraction, closed test section, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The contraction ratio is 9 to 1 and maximum speed in the test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine and airfoil.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.431-434
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• 2009

Conceptual study of an open-circuit type low-speed wind tunnel for test of wind turbine blade is conducted. The tunnel is constituted of a settling chamber, a contraction, closed and open test sections, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The open test section with dimension width of 1.8 m, height of 1.8 m and length of 4.14 m is adopted for aeroacoustic test. The contraction ratio is 9 to 1 and maximum speed in the closed test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine.

• 한국항공우주학회지
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• 제31권4호
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• pp.92-98
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• 2003

한양대학교 중형 아음속 풍동의 설계요구사항에 따라 균일도 증가 및 난류도 감소를 위한 최적설계를 수행하였다. 신뢰성 있는 풍동실험을 위해 먼저 풍동 시험부의 균일도와 난류강도 특성이 먼저 파악되어야 한다. 한양대학교 중형 아음속 풍동의 비균일도와 난류강도는 세 부분의 속도영역에서 피토관과 X형 열선프로브로 각각 측정되었다. 풍동 시험부의 유속이 증가함에 따라 비균일도가 작아졌으나 시험부의 측정단면이 확산부에 가까워질수록 비균일도가 크게 나타났다. 난류강도는 시험부 중앙에서 설계 요구조건에 비해 약간 높게 측정되었다.

• International Journal of Aeronautical and Space Sciences
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• 제2권1호
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• pp.103-109
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• 2001

Productivity enhancement program of wind tunnel testing has begun at Korea Aerospace Research Institute Low Speed Wind Tunnel (KARI LSWT). A previous test record of a canard airplane model was adopted to examine the current status of wind tunnel testing efficiency. The time consumed to perform testing activities from the model preparation to data collection was broken down and the results were compared with those of the recent Boeing low speed test result. The efforts to improve the wind tunnel productivity consisted of the installation of mini crane underneath of test section, fabricating lift device for image fairings, model configuration changing rigs and the modifications of external balance system. Time reductions for changing strut interface platform and installation of image fairings. These effects showed more than 70% improvement over the previous test time. Integration of the new and modified systems will improve productivity of wind tunnel testing in KARI LSWT.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.96-102
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• 2008

For centuries now, wind tunnels have been a key element in scientific research in a number of fields. Experimenting with racecars, airplanes, weather patterns, birds, and various other areas has been made much easier because of its development. In the racing field, for example, the information gathered from this testing can mean the difference between winning and losing a race. Weather simulations can also provide valuable information regarding building stability and safety. This has become very important when designing buildings today. Valuable information concerning bird flight has also been collected based on wind tunnel testing. Wind tunnels have a variety of important uses in the world today. Wind tunnel that used here is an open loop low speed wind tunnel. The fundamental principles of this tunnel is moving the air using exhaust fan In the rear side, and placing the cube in the external balance system which used to measure the working force. This experiment is using 50mm cube of finished wood. From this experiment we can get Drag Force (FD), The Reynolds Number (Re) and The Coefficient of Brae (CD).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1207-1214
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• 2001

The paper deals with the computational approach in analysis and design of pantograph panhead strips of high-speed railway in aerodynamic and aeroacoustic concerns. Pantograph is an equipment such that the electric power is supplied from catenary system to train. Due to the nature of complexity in high-speed fluid flow, turbulence and downstream vortices result in the instability in the aerodynamic contact between panhead strips and catenary system, and consequently generate the considerable levels of flow-induced sound. In this paper, based on the preceding low speed wind-tunnel test and simulations, the aerodynamic and aeroacoustic characteristics in low speed are analyzed.

• Wind and Structures
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• 제35권3호
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• pp.147-155
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• 2022

This research proposes a wind-lens turbine design that can startup and operate at a low wind speed (< 5m/s). The performance of the wind-lens turbine was investigated using CFD and wind tunnel testing. The wind-lens turbine consists of a 3-bladed horizontal axis wind turbine with a diameter of 0.6m and a diffuser-shaped shroud that uses the suction side of the thin airfoil SD2030 as a cross-section profile. The performance of the 3-bladed wind-lens turbine was then compared to the two-bladed rotor configuration while keeping the blade geometry the same. The 3-bladed wind-lens turbine successfully startup at 1m/s and produced a torque of 66% higher than the bare turbine, while the two-bladed wind-lens turbine startup at less than 4m/s and produced a torque of 186 % higher than the two-bladed bare turbine at the design point. Findings testify that adding the wind-lens could improve the bare turbine's performance at low wind speed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.33.2-33.2
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• 2011

The 'NREL Phase VI' model with a 10.06m diameter was tested in the NASA Ames tunnel to make a reference data of the computational models. The test was conducted at the one rotational speed, blade tip speed 38m/s and the Reynolds number of the sectional airfoils in that test was around 1E6. The 1/5 scale down model of the 'NREL Phase VI' model was used in this paper to study the power characteristics in low Reynolds number region, 0.1E6 ~ 0.4E6 which is achievable range for the conventional wind tunnel facilities. The torque generated by the blade was directly measured by using the torque sensor installed in the rotating axis for a given wind speed and rotational speed. The power characteristics below the stall condition, lambda > 4, was presented in this paper. The power coefficient is very low in the condition below the Re. 0.2E6 and rapidly increases as the Re. increases. And it still increases but the variation is not so big in the condition above the Re. 0.3E6. This results shows that to study the performance of the wind turbine blade by using the scaled down model, the Re. should be larger than the 0.3E6.

• 한국항공우주학회지
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• 제40권3호
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• pp.230-236
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• 2012

본 연구의 목적은 풍동 시험부의 속도산출에 필요한 속도측정시스템용 교정계수를 실험적으로 결정하는데 있었다. 교정실험은 국방과학연구소 저속풍동에서 표준 피토관을 이용하여 수행되었으며 이때의 교정속도 영역은 약 10~100 m/s이었다. 풍동교정실험결과의 유효성 평가를 위해 기존의 교정계수 측정결과와의 비교검토를 수행하였으며, 기존 교정 결과들과 잘 부합됨을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.361-366
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• 2001

The present study describes a practical estimation procedure about the pantograph under several severe aerodynamic load conditions. As the operating speed of the Korean Train Express(KTX) reaches 350km/h, structural safety at various conditions should be examined at the design stage. In the present study, a compact and reliable procedure is developed to get aerodynamic loads on each part of the pantograph regarding the typhoon condition, the train/tunnel interaction, the train/train interaction and the side wind condition. In the estimation procedure, 3-dimensional steady and unsteady CFD simulation around the high speed train facilitates assigning the external local flow condition around the pantograph. The procedure is verified using the results of the low speed wind tunnel test at JARI and applied to 7 flow conditions and 4 operation configurations.