• Title/Summary/Keyword: strut interference

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Numerical Evaluation of the Strut Interference and the 3-Run Image method for Wind Tunnel Tests

  • Chang, Byeong-Hee
    • International Journal of Aeronautical and Space Sciences
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    • v.1 no.2
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    • pp.17-21
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    • 2000
  • In order to correct the strut interference in wind tunnel tests, image methods are conventionally used. Because of their excessive extra runs, some alternatives have been tried to reduce the extra runs. In this study, these alternatives were reviewed and checked by the strut interference evaluation with the panel code, CMARC. The present work shows that the strut interference is free from neither model configuration nor model attitude. This dependency makes the alternatives to the image method unfeasible. The 3-run image method was also evaluated. It worked well even for the exaggerated windshield. At this point, reducing the image runs by neglecting parameters affecting minor influence would be best.

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Behavior of Strut in Concrete-filled FRP PSC Bridge using FBG Sensors (FBG센서를 이용한 콘크리트 충진 FRP 스트럿 보강 PSC 교량의 스트럿 거동 분석)

  • Chung, Won-Seok;Kang, Dong-Hoon;An, Zu-Og
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.6
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    • pp.11-15
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    • 2009
  • Recently, a new PSC (Prestressed Concrete) bridge system, which is supported by Concrete-filled fiber-reinforced polymer (CFFRP) strut, has been introduced. This bridge is able to reduce self-weight and increase the width of traditional PSC bridges. However, no relevant research has been reported on local behavior of CFFRP strut in the bridge system. The purpose of this study is to investigate local behavior of CFFRP struts using fiber Bragg grating (FBG) sensors. Field tests were performed to examine the hoop strains and longitudinal strains of the FRP strut under various lateral positions and velocities of a test truck. It has been observed that CFFRP strut is under compression regardless of vehicle speed and location. However, the CFFRP strut is sensitive to the lateral position of vehicles in terms of strain magnitude. Results also indicated that the FBG sensors can faithfully record the hoop and longitudinal strains of the FRP strut without electro-magnetic interference.

NUMERICAL STUDY OF MODEL AND WALL INTERFERENCE IN A SUPERSONIC WIND TUNNEL (초음속 풍동내에서의 모델과 벽면 간섭에 관한 수치적 연구)

  • Hong S. K.;Ahn H. K.
    • 한국전산유체공학회:학술대회논문집
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    • 1995.10a
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    • pp.213-218
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    • 1995
  • 마하수 4일때 초음속 풍동의 벽면과 모델지지부의 간섭에 관해 연구하였다. 특히 모델지지부 주위에서의 충격파 형성과 sting, strut 그리고 second throat에서의 반사 충격파의 상호 작용에 연구의 촛점을 두었다. 수치 기법은 내재적 플럭스 차분 분할기법 (implicit flux-difference splitting technique)을 사용하였다. 2차원과 3차원 유동해석 결과로부터 모델지지부 후류의 유동에 미치는 diffuser 출구 경계조건의 영향을 알아보았다.

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A study on the Applied Technology of a Case for Underground Structures Considering Downtown Site Conditions (도심지 여건을 고려한 지하구조물 공사사례의 시공기술요소에 관한 연구)

  • Lee, Il-Jae;Maeng, Eun-Ju;Son, Hyeok;Lee, Jong-I;Kim, Hyung-Wan
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.189-192
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    • 2012
  • Underground structure construction in the downtown is very difficult despite the development of construction technology. We have been a lot of research in order to solve the problem, it was a remarkable achievement. But there are still many difficulties. This study is to analyze the construction technology to demolish the existing underground structures and to build new building applied topdown method at the same time. This technology was effective to suppress interference between the exsisting structure and new building. Therefore, this technology is expected to be able to be used in similar cases in the future.

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Study on the Propulsion System Integration Optimization for a Turboprop Aircraft (터보프롭 항공기 추진기관 시스템 종합 최적 설계 연구)

  • 공창덕;김진원
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1995.05a
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    • pp.71-81
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    • 1995
  • The Propulsion System Integration can be defined as the optimization technology of combining the propulsion system components with the airframe to achieve the overall aircraft misson performance goals. The disposition of propulsion system components on engine compartment enveloped by front fuselage and fire bulkhead is very restricted because of the interference with nose L/G and engine mountig strut. The design of components depends on the traditional technical data base. The engine satisfying a customer's ROC was selected among worldwide existing engines by the comparision studies of performance analysis with enigine installed effect, future growth potential, ILS, and application to aircrafts, etc. The ground test of the propulsion system integration was performed in the test cell and on the aircraft to assure the function of the components. The flight test was performed to confirm complying the performance requirements.

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Data Correction of Wind Tunnel Test Results for Smart UAV Power Model (스마트무인기 파워효과 풍동시험 데이터 보정)

  • Cho, Tae-Hwan;Chung, Jin-Deog;Choi, Sung-Wook;Kim, Yang-Won;Chang, Byeong-Hee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.2
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    • pp.130-135
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    • 2007
  • Wind tunnel test for Smart UAV power model has been conducted at KARI LSWT for about 3 months. The static model is used for the base plane and the power effect of tilt rotor is simulated by the tilt-rotor test rig installed in the test section. Although the genuine power effect is the difference between power-on and off tests. The existence of struts for power effect test produced unwanted form of interference and caused the change in flow angularity. To precisely evaluate power effect, a special approach is applied to Smart UAV test.