• 제목/요약/키워드: 파랑제어

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Numerical Simulation of Velocity Fields and Vortex generation by a Submerged Breakwater installed Area that Depth of Water changes (변동수심역에 설치된 잠제 주변의 유속장과 와의 발생에 대한 수치모의)

  • 김도삼;이광호
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2002.08a
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    • pp.42-48
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    • 2002
  • 잠제는 주로 입사하는 파를 천단에서 강제쇄파시키거나 마찰을 통한 에너지 감소로 파를 제어하므로 잠제의 천단수심과 천단의 길이는 잠제의 성능에 가장 중요한 요소라고 할 수 있다. 일반적으로 잠제의 천단수심이 깊은 경우 잠제에 의한 파랑제어를 충분히 기대할 수 없으므로 입사파의 제어를 위한 적정한 천단수심이 필요하게 되고 천단수심이 얕아짐에 따라 천단상에서 파의 대칭성이 무너지는 비선형성분이 탁월해진다. (중략)

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Control of Short-period and Solitary Waves Using Two-rowed Impermeable Rectangular Submerged Dike (2열 불투과성 사각형 잠제를 이용한 단주기파랑 및 고립파의 제어)

  • Lee, Kwang-Ho;Jung, Sung-Ho;Ha, Sun-Wook;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.4
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    • pp.203-214
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    • 2010
  • This study numerically investigates the wave control of 2-rowed Impermeable Rectangular Submerged Dike(IRSD) with an object of how to control short-period and solitary waves simultaneously based on the Bragg resonance phenomenon that elevates the wave control performance. The boundary integral method using Green formula and the 3-D one-field Model for immiscible TWO-Phase flows (TWOPM-3D) by 3-D numerical wave flume have been used for the numerical predictions for short-period and solitary waves, respectively. These numerical models were verified through the comparisons with the previously published numerical results by other researchers. Through the parametric tests of numerical experiments for short-period waves, an optimum model of 2-rowed IRSD of a lowest transmission coefficient has been found. Furthermore, the performances of 3-D wave control for solitary waves were evaluated for the various free board, crown widths and gap distance between dikes, and have been compared with those of a single-rowed IRSD. Numerical results show that a 2-rowed IRSD with a less cross sectional area than 1-rowed one improves the wave attenuation performances when it is compared to that of single-rowed IRSD. Within the test frequency ranges of the numerical simulations conducted in this study, 2-rowed IRSD with an optimum gap distance shows an outstanding improvement of the wave attenuation up to 58% compared to that of single-rowed IRSD.

중소어항의 항내매몰 방지대책

  • 윤성진;김규한;편종근
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1997.10a
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    • pp.63-67
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    • 1997
  • 파랑이 탁월한 영역에 존재하는 중소어항의 대부분을 항내매몰이 중요문제 중의 하나로서, 입ㆍ출항의 곤란 및 반복되는 준설경비의 소요 등으로 경제적 문제를 겪고있다. 따라서 이와 같은 문제를 장기적으로 해결하기 위해서는 항내매몰의 근본적 원인을 빠른 시일 내에 정확히 파악하고, 그 대책공법을 강구할 필요가 있다. 본 연구는 이러한 문제를 해결하기 위해 파랑 및 연안류제어 구조물의 설치 및 배치 등을 이용한 항내매몰 방지대책을 설정하여 각각의 연안류 및 해빈변형제어효과를 검토하고 항내매몰에 미치는 영향을 검토해 보았다. (중략)

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Vibration Control of Offshore Platform using Tuned Mass Damper (동조질량감쇠기를 이용한 해양구조물의 진동제어)

  • Kim, Ju Myung;Lee, Gyu Won
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.73-79
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    • 2004
  • Tuned Mass Damper (TMD) was applied to control the vibration of an offshore structure due to ocean waves. The errors caused by the linearization of the fluid-structure interaction effect and the phenomena when using the linearized equation of motion in TMD design were analyzed. To determine the performance of TMD in controlling vibration, both regular waves with varying periods and irregular waves with different significant wave heights were used. When the offshore structure received regular waves with a period similar to the first natural period of structure. TMD performed well in terms of response reduction. Such was not the case for the other periods. however, In the case of irregular waves, TMD triggered the reduction of structural response for waves with relatively small significant wave height. For irregular waves with relatively big significant wave height, however, TMD did not show any control effect. Therefore, TMD is useful in reducing offshore structural vibration due to ambient waves, thereby helping secure fatigue life.

An Experimental Study on the improvement of harbor tranquility by Multi-cylinder piles Structure (다원주 파일군 구조물에 의한 항내 정온도 향상에 관한 실험적 연구)

  • Lee, Sang-Hwa;Jang, Eun-Cheul;Jeong, Dong-Hwa
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.1
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    • pp.66-72
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    • 2007
  • In order to control waves in coastal zones effectively, multi-cylinder piles as the economical structures are suggested. A three dimensional hydraulic model experiment was performed to investigate the hydraulic characteristics of the structure. An experimental study was carried out research the effect of wave control and harbor tranquility through the wave height analysis for the existing concrete wave breaker and the structure with acrylic multi-cylinder piles type at the same location. In the results, the effective order of harbor tranquility is shown as the wave breaker > the staggered arrangement of multi-cylinder piles > the regular arrangement of multi-cylinder piles.

항주파 파고 감쇄의 부소파제에 대한 실해상 실험 연구

  • O, U-Jun;Sin, Jeong-Hun;Park, Tae-Geon;Ham, Yeon-Jae;Jeong, U-Cheol;Park, Je-Ung;Kim, Do-Jeong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.118-119
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    • 2013
  • 마리나 시설 내 계류된 선박 및 레저장비를 악천 후 해상상태와 선박 운항에 의해 발생된 파로부터 장비 및 인명의 안전을 위한 파 제거 장치가 필요하다. 본 연구에서는 국내 각 지자체의 수요에 부응하고 시설 및 인명의 안전을 위한 소파 시스템개발을 목적으로 시제품 제작(설계, 해석, 수조시험 등 수행완료)하였다. 실해상 성능시험에서 항주파의 발생을 위해 시험선박 선정하였으며, 소파장치 전후의 파고계측 등을 위해 부가물을 계측하여 파고를 촬영 및 계측하였다. 개발된 소파장치의 실해상 시험임을 감안해 해상 주위의 조류, 풍속, 인근 해역에서 오는 파랑변형 등에 따른 파랑요소를 고려하여 시험하였다. 부소파제는 약 40~80% 의 에너지 감소율을 보였으며, 유의파고 조건에서 42%의 에너지 감소율을 보였다.

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Wave Control by Two-Rowed Fixed Floating Breakwaters near the Water Surface (수면부근에 설치된 이열고정부방파제에 의한 파랑제어의 해석)

  • 김도삼;이재석;이봉재
    • Journal of Ocean Engineering and Technology
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    • v.15 no.4
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    • pp.1-7
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    • 2001
  • Mainly, Floating Breakwaters (FBs) have been constructed in many coastal regions due to the advantages of the coastal environment and construction cost. In general, the FB becomes fixed or its width broadened because the movement of the FB comes to be large and its the wave control function lower for the long period incident waves. This study discusses the wave control function of two-rowed Fixed Floating Breakwater (FFBs) that have narrower width than that of the one-rowed FFB by using numerical approach. Boundary Element Method (BEM) based on the Green formula and Eigenfunction Expansion Method (EEM) are applied to evaluate the three-dimensional wave transformation near the wave fields of two-rowed FFBs. The validity of the present study is confirmed by comparing it with the results of Ijima et al. (1974) and Yoshida et al. (1992) for the one-rowed Fixed Floating Structure. It is revealed that the wave control function of two-rowed FFBs is more effective than that of the one-rowed FFB.

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