• Title/Summary/Keyword: wind tunnel

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Wind tunnel effect analysis for MEXICO wind turbine model (MEXNEXT 풍력발전기 풍동 시험에 대한 풍동 영향 분석)

  • Shin, Hyungki;Lim, Jongsoo;Jang, Moonseok
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.59.1-59.1
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    • 2011
  • In this research, CFD calculation was implemented to analyze wind tunnel effect or rotor experiment in wind tunnel. One case included model wind turbine and all wind tunnel geometries. The other case include only rotor and nacelle system. Star-CCM+ was used for CFD analysis and rigid body motion around rotor area was applied to simulate rotating rotor. As for turbulence model, K-omega SST was used. The results were compared in 15m/s inflow condition. These results shows a good agreement with the measurement. Then, the result without wind tunnel was slightly different to the result with wind tunnel. Thus, in the case of Mexnex wind tunnel measurement, the wind tunnel don't affect the measurement result. Then, this wind tunnel and rotor size ratio can be reference for wind tunnel experiment of wind turbine rotor.

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The wind tunnel measuring methods for wind turbine rotor blades

  • Vardar, Ali;Eker, Bulent
    • Wind and Structures
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    • v.7 no.5
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    • pp.305-316
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    • 2004
  • In this study, a wind tunnel, that has been developed for experiments of wind turbine rotor blades, has been considered. The deviations of the measurements have been examined after this wind tunnel had been introduced and the measurements on it had been explained. Two different wind turbine rotor blades miniatures have been used for getting better results from the experiments. The accuracy of measurements have been experimented three times repetitively and examined statistically. As a result, wind speed values which this type of wind tunnel and wind turbine rotors need for starting, wind speed in the tunnel, temperature and moisture values, the number of rotor's revolution, and the voltage that is produced in 102 ${\Omega}$ resistance and current values have been determined to be fixed by measurements used. This type of wind tunnel and wind turbine rotor' performance difference and the difference of revolution figures have been determined to be fixed by measurements used.

Wind tunnel test of wind turbine in United States and Europe (미국과 유럽의 풍력터빈 풍동실험)

  • Chang, Byeong-Hee
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.42-46
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    • 2005
  • In spite of fast growing of prediction codes, there is still not negligible uncertainty in their results. This uncertainty affects on the turbine structural design and power production prediction. With the growing size of wind turbine, reducing this uncertainty is becoming one of critical issues for high performance and efficient wind turbine design. In this respect, there are international efforts to evaluate and tune prediction codes of wind turbine. As the reference data for this purpose, field test data is not appropriate because of its uncontrollable wind characteristics and its inherent uncertainty. Wind tunnel can provide controllable wind. For this reason, NREL has done the full scale test of the 10m turbine at NASA-Ames. With this reference data, a blind comparison has been done with participation of 18 organizations with 19 modeling tools. The results were not favorable. In Europe, a similar project is going on. Nine organizations from five countries are participating in the MEXICO project to do full scale wind tunnel tests and calculation with prediction codes. In this study. these two projects were reviewed in respect of wind tunnel test and its contribution. As a conclusion, it is suggested that scale model wind tunnel tests can be a complementary tool to calculation codes which were evaluated worse than expected.

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The influence of model surface roughness on wind loads of the RC chimney by comparing the full-scale measurements and wind tunnel simulations

  • Chen, Chern-Hwa;Chang, Cheng-Hsin;Lin, Yuh-Yi
    • Wind and Structures
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    • v.16 no.2
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    • pp.137-156
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    • 2013
  • A wind tunnel test of a scaled-down model and field measurement were effective methods for elucidating the aerodynamic behavior of a chimney under a wind load. Therefore, the relationship between the results of the wind tunnel test and the field measurement had to be determined. Accordingly, the set-up and testing method in the wind tunnel had to be modified from the field measurement to simulate the real behavior of a chimney under the wind flow with a larger Reynolds number. It enabled the results of the wind tunnel tests to be correlated with the field measurement. The model surface roughness and different turbulence intensity flows were added to the test. The simulated results of the wind tunnel test agreed with the full-scale measurements in the mean surface pressure distribution behavior.

A GUIDE FOR NUMERICAL WIND TUNNEL ANALYSIS IN ORDER TO PREDICT WIND LOAD ON A BUILDING (건축물의 풍하중을 예측하기 위한 수치풍동기법)

  • Lee, Mung-Sung;Lee, June-Hee;Hur, Nahm-Keon;Choi, Chang-Koon
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.5-9
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    • 2010
  • A numerical wind tunnel simulation is performed in order to predict wind loads acting on a building. The aim of the present study is to suggest a guideline for the numerical wind tunnel analysis, which could provide more detail wind load distributions compared to the wind code and expensive wind tunnel experiments. To validate the present numerical simulation, wind-induced loads on a 6 m cube model is predicted. Atmospheric boundary layer is used as a inlet boundary condition. Various effect of numerical methods are investigated such as size of computational domain, grid density, turbulence model and discretization scheme. The appropriate procedure for the numerical wind tunnel analysis is suggested through the present study.

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A Study on the Concept Design of Vertical Wind Tunnel for Skydiver (고공 강하용 수직풍동의 개념설계에 관한 연구)

  • Cho, Hwan Kee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.2
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    • pp.83-90
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    • 2018
  • This paper describes a case study on the design factor analysis of vertical wind tunnel for skydiver's training or experiencing of paradropping exercise in the air. The case study of vertical wind tunnel design is to provide the knowledges on effects of parameter's variation when it is applied to overall or partial duct of tunnel circuit. The analysis of design parameters based on pressure loss are produced one by one through the tunnel components from the flight chamber because the wind tunnel must satisfy the requirement of flight chamber such as flow speed, quality and quantity. Results shows the various effects of parameter variation with pressure loss in the wind tunnel circuit. Pressure loss should be based on the determination of fan and power system which can be selected from market or new design.

Airfoil Testing to Obtain Full-range Aerodynamic Characteristics based on Velocity Field Measurements Utilizing a Digital Wind Tunnel (익형의 전 범위 받음각에서 공력특성 시험이 가능한 디지털 풍동의 개발 및 속도장 측정)

  • Kang, Sangkyun;Kim, Jin-Ok;Kim, Yong-Su;Shin, Won-Sik;Lee, Sang-Il;Lee, Jang-Ho
    • New & Renewable Energy
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    • v.18 no.3
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    • pp.60-71
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    • 2022
  • A wind tunnel provides artificial airflow around a model throughout the test section for investigating aerodynamic loads. It has various applications, which include demonstration of aerodynamic loads in the building, automobile, wind energy, and aircraft industries. However, owing to the high equipment costs and space-requirements of wind tunnels, it is challenging for numerous studies to utilize a wind tunnel. Therefore, a digital wind tunnel can be utilized as an alternative for experimental research because it occupies a significantly smaller space and is easily operable. In this study, we performed airfoil testing based on velocity field measurements utilizing a digital wind tunnel. This wind tunnel can potentially be utilized to test the full-range aerodynamic characteristics of airfoils.

A Study on the Development for the Airfoil of Wind Turbine Blade using Digital Wind Tunnel (디지털 풍동을 활용한 풍력 발전기 날개 단면 형상 개발에 관한 연구)

  • Kang, Deok Hun;Woo, Young-Jin;Lee, Jang Ho
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.5
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    • pp.42-47
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    • 2012
  • Newly updated wing shape to apply small vertical wind turbine is tested with digital wind tunnel in this study. Digital wind tunnel is designed to reduce length of wind tunnel and also to maximize its area of test section. Same DC fans of ninety six are installed in the end side of its rectangular duct and air can be blown out to the other side to have uniform flow with same electricity power. New wing is concluded using experimental plan and analysis with 4-parameters and 3-levels, and tested with digital wind tunnel. It shows better performance in lift to drag ratio, and can applied to the wind turbine for the higher torque and lower thrust.

A Study on the Comparison of wind pressure on the member of Container Crane using Wind tunnel test and CFD

  • An, Tae-Won;Lee, Seong-Wook;Han, Dong-Seop;Han, Geun-Jo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.321-325
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    • 2006
  • Because strong wind is one of the few forces that, although considered in container crane design, still cause significant damage, a container crane was tested to investigate wind load characteristic in uniform flows. So, this study measured an external point pressure at the each members of a container crane according to a wind direction and a shape of members in a wind-tunnel test. The result of this test was compared to those of computation fluid dynamics using a CFX 10. The scale of a container crane model for wind tunnel test applied similarity scales to consider the size of the wind tunnel test section and the boundary condition for CFD is like wind tunnel test.

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Aerodynamic effects of subgrade-tunnel transition on high-speed railway by wind tunnel tests

  • Zhang, Jingyu;Zhang, Mingjin;Li, Yongle;Fang, Chen
    • Wind and Structures
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    • v.28 no.4
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    • pp.203-213
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    • 2019
  • The topography and geomorphology are complex and changeable in western China, so the railway transition section is common. To investigate the aerodynamic effect of the subgrade-tunnel transition section, including a cutting-tunnel transition section, an embankment-tunnel transition section and two typical scenarios for rail infrastructures, is selected as research objects. In this paper, models of standard cutting, embankment and CRH2 high-speed train with the scale of 1:20 were established in wind tunnel tests. The wind speed profiles above the railway and the aerodynamic forces of the vehicles at different positions along the railway were measured by using Cobra probe and dynamometric balance respectively. The test results show: The influence range of cutting-tunnel transition section is larger than that of the embankment-tunnel transition section, and the maximum impact height exceeds 320mm (corresponding to 6.4m in full scale). The wind speed profile at the railway junction is greatly affected by the tunnel. Under the condition of the double track, the side force coefficient on the leeward side is negative. For embankment-tunnel transition section, the lift force coefficient of the vehicle is positive which is unsafe for operation when the vehicle is at the railway line junction.