Journal of Korean Society of Coastal and Ocean Engineers (한국해안해양공학회지)

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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Wave Diffraction and Multi-Reflection Around Breakwaters

방파제 주위에서 발생하는 파랑의 회절 및 다중반사

  • Lee, Changhoon (Department of Civil and Environmental Engineering, Sejong University) ;
  • Kim, Min-Kyun (Department of Civil Engineering, The University of Seoul) ;
  • Cho, Yong-Jun (Department of Civil Engineering, The University of Seoul)
  • 이창훈 (세종대학교 토목환경공학과) ;
  • 김민균 (서울시립대학교 토목공학과) ;
  • 조용준 (서울시립대학교 토목공학과)
  • Published : 2005.12.01
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Abstract

In this study, we get an analytical solution for the diffraction and multi-reflection around a semi-infinite breakwater and breakwaters with a gap by using the solution of Penney and Price (1952). We find analytical solutions for single- and multi-reflections around the breakwaters by assuming that the reflected waves are regarded to be those diffracting through a breakwater gap. On the basis of these solutions, it is possible to understand the wave diffraction with different cases of incident wave direction and breakwater layout. These solutions may help harbor engineers to understand the phenomena of diffraction and multi-reflections around the breakwaters. These solutions may also be used to evaluate the applicability of wave transformation models which are used in designing coastal structures.

본 연구에서 Penney and Price(1952)의 해석 해를 사용하여 반무한방파제, 양익방파제 등에서 발생하는 파랑의 회절 및 다중반사 현상에 대한 해석 해를 구하였다. 구조물에서의 반사 현상을 양익방파제를 지나는 회절 현상으로 간주하여 방파제에서 발생하는 단일반사 및 다중반사 현상을 규명하였다. 이를 바탕으로 방파제의 위치와 입사파랑의 각도에 따라 다른 경우에도 해석해를 구할 수 있다. 이러한 해석해는 국내의 항만 실무자들에게 회절 및 다중반사 현상에 대한 이해를 도울 수 있을 것이며, 실무의 해안 및 항만 구조물 설계 시에 사용되는 수치프로그램들의 정확도를 판단할 수 있는 비교 대상으로 사용될 수 있으리라 판단된다.

Keywords

References

  1. 이해균, 이길성, 이창훈 (1998). 회절현상의 관점에서 본 포물선형 완경사방정식의 비교. 한국해안해양공학회지, 10(1), 1-9
  2. 편종근, 이용규, 김철 (1987). Mathieu함수를 이용한 파랑의 회절에 관한 연구. 공학기술연구소논문집, 명지대학교, 2, 1-22
  3. Engquist, B. and Majda, A. (1977). Absorbing boundary conditions for the numerical simulation of waves. Mathematics of Computation, 31(139), 629-651 https://doi.org/10.2307/2005997
  4. Goda, Y. (1985). Random Seas and Design of Maritime Structures. University of Tokyo Press
  5. Lee, C., Kim, G. and Suh, K.D. (2003). Extended mild-slope equation for random waves. Coastal Engineering, 48, 277-287 https://doi.org/10.1016/S0378-3839(03)00033-4
  6. Lee, C., Park, W.S., Cho, Y.S. and Suh, K.D. (1998). Hyperbolic mild-slope equations extended to account for rapidly varying topography. Coastal Engineering, 34, 243-257 https://doi.org/10.1016/S0378-3839(98)00028-3
  7. Madsen, P.A. (1983). Wave reflection from a vertical permeable wave absorber. Coastal Engineering, 7, 381-396 https://doi.org/10.1016/0378-3839(83)90005-4
  8. Madsen, P.A. and Sorensen, O.R. (1992). A new form of the Boussinesq equations with improved linear dispersion characteristics. Part 2. A slowly varying bathymetry. Coastal Engineering, 18, 183-204 https://doi.org/10.1016/0378-3839(92)90019-Q
  9. Nwogu, O. (1993). Alternative form of Boussinesq equation for nearshore wave propagation. J. Waterway, Port, Coastal and Ocean Engineering, 119, 618-638 https://doi.org/10.1061/(ASCE)0733-950X(1993)119:6(618)
  10. Penney, W. G. and Price, A. T. (1952). The diffraction theory of sea waves by breakwaters and the shelter afforded by breakwaters. Philos. Tran. R. Soc. London, Series A, 244, 236-253 https://doi.org/10.1098/rsta.1952.0003
  11. Sobey, R.J. and Johnson, T.L. (1986). Diffraction patterns near narrow breakwater gaps. J. Waterway, Port, Coastal and Ocean Engineering, 112(4), 512-528 https://doi.org/10.1061/(ASCE)0733-950X(1986)112:4(512)
  12. Sommerfeld, A. (1896). Mathernatische Theorie der Diffraction. Mathematische Annalen, 47, 317-374 https://doi.org/10.1007/BF01447273
  13. Suh, K.D., Lee, C. and Park, W.S. (1997). Time-dependent wave equations for wave propagation on rapidly varying topography. Coastal Engineering, 32, 91-117 https://doi.org/10.1016/S0378-3839(97)81745-0