• Title/Summary/Keyword: 풍동실험

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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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An Experimental Study on Wind Aerodynamic Improvement of Steel Composite Cable Stayed Bridge having π-shaped Girder (π형 주형을 가진 강합성 사장교의 공기역학적 제진방법에 대한 실험적 연구)

  • Chang, Dong Il;Min, In Ki
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.801-811
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    • 1998
  • In this paper, aerodynamic properties and improvements of the ${\pi}-shaped$ stiffening girder is studied by wind tunnel tests in steel composite cable stayed bridge. As an improvement device, fairing, extension, post and flap is tested. and the best improved section is selected and estimated on angles of attack, damping ratios and turbulent flows. It is shown that the selected fairing is effective to improve the aerodynamic stability. And this study can be utilized as a database of wind-resistant methodology of steel composite cable stayed bridge.

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The method using dynamic load and static load figures out gust factor of the membrane structure (동적하중과 정적하중을 이용한 막구조의 거스트 계수 산출 방법)

  • Wang, Ben-Gang;Jeong, Jae-Yong;You, Ki-Pyo;Kim, Young-Moon
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.19-24
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    • 2008
  • The thesis is for gust factor needing when calculate the wind resistance design. For the gust factor, to the membrane structural model, carry through the wind tunnel test and the static load test. Therefore, at first through the tensile test of the fabric material, designate the material of the membrane structural model. Then, to saddle, wave, arch and point four kinds of basic shape membrane structural models, carry on the wind tunnel test, determine their dynamic load and distortion on lateral direction. Finally, according to distort situation of the membrane structure in the wind tunnel test, carry on the static load experiment outside of the wind tunnel, calculate static load which corresponding with distort. According to dynamic load and the static load, figure out gust factor of these kinds of basic membrane structure.

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A Grid Web Portal for a Wind Tunnel simulation (가상 풍동 구현을 위한 그리드 웹 포탈 서비스)

  • Kim Eun-kyung;Kim Yoonhee;Cho Junghyun;Kim Chongam;Lim Sang Beom
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.1039-1041
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    • 2005
  • 가상 풍동 실험은 슈퍼컴퓨터와 같은 고성능의 계산 지원과 실험을 위한 깊은 지식을 요구하여 실험을 수행하는데 많은 어려움이 수반된다. 그리드[1][2]는 산재한 자원을 연계하여 고성능 응용을 위해 효율적으로 활용할 수 있도록 하는 기반구조를 제공한다. 본 논문에서는 그리드 자원을 활용하여 가상 풍동 실험을 빠르고 효과적으로 수행할 수 있는 그리드 웹 포탈 서비스를 제안한다. 통합된 포탈 서비스를 통하여 사용자의 응용 및 실험환경의 요구사항을 반영한 격자생성, 계산 작업, 작업 모니터링, 결과 가시화를 효율적으로 수행한다.

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Experimental Study on the Aerodynamic Characteristics of a High-speed Ground Vehicle Moving in a Channel (채널 내를 운행하는 초고속 지상 운행체의 공력특성에 관한 실험적 연구)

  • Choi, Dong-Soo;Kim, Dong-Hwa;Cho, Jin-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.8
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    • pp.72-81
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    • 2004
  • A Wind tunnel test for a high speed ground vehicle was conducted to investigate the aerodynamic interactions between the vehicle and a solid channel. The free stream velocity was 30m/see and Reynolds number per unit length was $3.1{\times}10^5/m$. Experimental devices such as a variable channel ground and guide way were used for the test. As the vehicle was close to the channel ground and guide way, lift was significantly increased, drag was slightly decreased and pitching moments were restricted to augment static stability. Using smoke-wire, flow visualization was made to confirm these results by comparing the channel and non-channel flow characteristics of the vehicle. Under the influence of the channel ground and guide way, the flow beneath the vehicle was not discharged outside wing end plates, which was the major reason of the increase in lift of the vehicle.

A Proposal of the Wind Pressure Coefficient and Simplified Wind Load Estimating Formula for the Design of Structural Frames of the Low-Rise Buildings (저층건축물의 구조골조 설계용 풍압계수 및 풍하중 평가 약산식의 제안)

  • Park, Jae Hyeong;Chung, Yung Bea;Ha, Young Cheol
    • Journal of Korean Society of Steel Construction
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    • v.21 no.3
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    • pp.289-299
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    • 2009
  • This study summarizes basic results on the characteristics of mean wind pressure distribution on rectangular low-rise buildings with various breadths and depths through simultaneous multi-point wind pressure test. 5 types of rectangular wind pressure test models with various breadths and depths have been made for this study. Wind pressure tests are conducted on the Boundary Layer Wind Tunnel at Kumoh National Institute of Technology. The characteristics of mean wind pressure distribution with respect to various breadths and depths of low-rise buildings are analyzed into windward face, leeward face and side faces of building. From the results, new wind pressure coefficients and simplified wind load estimating formula for the resonable design of the structural frames of low-rise building were proposed.