Journal of Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회논문집)

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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The Multidirectional Random Wave Diffraction in a Partial-Reflecting Harbor due to a Submarine Pit

Pit에 의한 부분반사율을 갖는 항내에서의 다방향 불규칙 파랑회절에 관한 연구

  • Kim, Sung-Duk (Dept. of Civil & Environment Engineering, Cheongju University) ;
  • Lee, Hong-Sik (Department of Civil Engineering, Chung-Ang University)
  • 김성덕 (청주대학교 토목환경공학과) ;
  • 이홍식 (중앙대학교 토목공학과)
  • Published : 2008.06.30
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Abstract

The present study is to estimate the effects of diffracted wave fields in a harbor and around harborentrance due to random waves, when a navigation channel is dredged in the vicinity of the a harbor entrance. The cross sections of harbor boundary are considered to be partial or full reflection in this study. The numerical simulation has been performed by the boundary element method, which is to discrete segments of pit- and harbor- boundary with the algorism of auto generated elements. The incident wave conditions are specified using discretized forms of the Mitsuyasu's frequency spectrum and directional function. The results of the present numerical simulation agreed well with those of the published experimental data. It is shown that the ratios of wave height reduction are about 20% for the case of fully reflecting boundary, and 10% for the case of partially reflecting boundary by the effect of placing a pit, respectively.

본 연구는 항만입구(항구) 부근에 항로가 준설되었을 경우, 항내 및 항구 주위에서 회절되는 파랑장의 효과를 예측하기 위한 것이다. 본 연구에서 항만경계의 단면은 부분반사 혹은 완전반사로 고려한다. 본 수치모의 계산은 자동경계요소 알고리즘으로 Pit 및 항만경계의 경계요소(segment)를 이산화한 경계요소법에 의해 실시하였다. 입사파 조건은 Mitsuyasu의 주파수스펙트럼과 방향함수의 이산화된 형태를 사용하여 특정화하였다. 본 계산치의 결과는 기존에 발표된 실험치의 결과와 잘 일치하였다. Pit 설치의 효과에 의해 파고감소의 비율은 완전반사 경계의 경우에 대하여 약 20%, 그리고 부분반사 경계의 경우에 대하여 약 10% 정도인 것으로 나타나고 있다.

Keywords

References

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