Journal of Navigation and Port Research (한국항해항만학회지)

Korean Institute of Navigation and Port Research (한국항해항만학회)
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Numerical Analysis of Reflection Characteristics of Perforated Breakwater with a Resonant Channel

공진수로 내장형 유공방파제의 반사특성에 관한 수치해석 연구

  • Kim, Jeong-Seok (Department of Convergence Study on Ocean Science and Technology, Korea Maritime and Ocean University) ;
  • Seo, Ji-Hye (Department of Convergence Study on Ocean Science and Technology, Korea Maritime and Ocean University) ;
  • Lee, Joong-Woo (Division of Civil Engineering and SOST, Korea Maritime and Ocean University) ;
  • Park, Woo-Sun (Coastal Development & Ocean Energy Research Division, Korea Institute of Ocean Science and Technology)
  • 김정석 (한국해양대학교 해양과학기술융합학과) ;
  • 서지혜 (한국해양대학교 해양과학기술융합학과) ;
  • 이중우 (한국해양대학교 건설공학과) ;
  • 박우선 (한국해양과학기술원 연안개발에너지부)
  • Received : 2014.08.25
  • Accepted : 2014.10.10
  • Published : 2014.10.31
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Abstract

In this study, a new concept perforated breakwater is proposed, which is having resonant channels. In the channel, perforated plate is installed for dissipating wave energy induced by flow separations. The breakwater has two advantages compared with conventional perforated breakwater having wave chamber with slotted walls. One is easy to control the target wave condition for dissipating wave energy, and the other is having the high structural safety because the structural members are not exposed to impact waves, directly. To evaluate wave reflection characteristics of the proposed breakwater, numerical experiment was carried out by using Galerkin's finite element model based on the linear potential theory. The results indicated that considerable energy dissipation occurs near the resonant period of channel, and wave reflection characteristics are affected by channel shape, location and opening ratio.

본 연구에서는 공진을 유도하는 수로를 이용한 새로운 개념의 유공방파제를 제안하려 한다. 공진수로에는 유공판을 설치하여 흐름분리현상에 의한 파랑에너지의 소산을 유도한다. 종래의 수실과 유공벽을 이용한 방파제에 비하여 공진수로 내장형 유공방파제는 두 가지의 장점을 들 수 있는데, 하나는 목표 차단파랑에 따라서 수로의 설계가 용이하며 보다 장주기 파랑에 대하여도 적용이 가능하다. 또 하나는 유공부가 쇄파력이 집중되는 수면부근보다 아래에 위치함으로써 구조적 안정성이 개선된다. 파랑에너지의 소산은 방파제 전면에서의 반사율로서 평가하였고, 수치해석은 선형 포텐셜 이론에 기초한 Galerkin의 유한요소모델을 이용하였다. 수로의 고유주기와 입사파의 주기가 일치하는 부근에서 적절한 에너지 손실을 확인할 수 있었으며 에너지 손실의 양은 수로의 형상, 위치 및 유공율의 영향을 받았다.

Keywords

References

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