Analysis of Wave Fields over Submerged Breakwaters

잠제 주변의 파랑장 해석

  • Published : 1999.06.01

Abstract

A numerical model is represented to calculate the wave fields such as the reflected waves, the transmitted waves and the depth-averaged velocities over submerged breakwaters for the normally incident wave trains of nonlinear mono-chromatic wave and solitary wave. The finite amplitude shallow water equations with the effects of bottom friction are solved numerically in time domain using an explicit dissipative Lax-Wendroff finite difference method. The numerical model is verified by comparisons with the other numerical results and the measured data. It is found that the submerged breakwater may be more useful for protecting the energies of monochromatic waves rather than solitary waves. Finally, the armor stability on submerged breakwater is indirectly analyzed using the hydrodynamic characteristics of flow fields.

마찰의 효과가 고려된 유한 진폭 천수방정식을 이용하여 잠제 주변의 파랑장, 잠제에 의하여 발생되는 반사파와 투과파 뿐만 아니라 시간과 공간에 따른 자유수면 및 흐름의 동수역학적인 거동 특성을 해석할 수 있는 Lax-Wendroff 유한차분 수치모형이 수립되었다. 비선형 규칙파와 고립파가 입사하는 경우에 대한 해석 결과를 기존의 수치해 및 실험자료와 비교하여 수치모형이 만족스럽게 검증되었다. 규칙파에 대한 해석에서 잠제 전면에서 발생되는 반사파와 관련된 시간과 공간에 따른 자유수면의 변화나 흐름특성이 투과파의 그것보다 강하게 발생되는 것으로 나타나, 본 연구에서 해석된 제한적인 조건하에서는 잠제가 외해에서 내습하는 파랑에너지를 효율적으로 차단하는 것으로 밝혀졌다. 그러나 고립파의경우는 대부분의 파랑에너지가 잠제에 의하여 차단되지 않고 투과되는 것으로 나타났다. 마지막으로 파랑장의 동수역학적인 거동특성으로부터 잠제를 피복하고 있는 피복재의 안전성과 관련된 해석이 간접적으로 수행되었다.

Keywords

References

  1. J. Waterway. Port. Coastal and Ocean Engrg. v.115 no.2 Stability of reef breakwaters Ahrens, J.P.
  2. Design and Construction of Mounds for Breakwaters and Coastal protection Brunn, P.
  3. Water Wave Mechanics for Engineers and Scientists Dean, R.G.;Dalrymple, R.A.
  4. J. Waterway, Port, Coastal and Ocean Engrg. v.124 no.2 Numerical model of wave run-up, overtopping, and regeneration Dodd, N.
  5. Rept. No. KH-R-38, W. M. Keck Lab. of Hydr. and Water Resour. California Inst. of Tech. Tsunamits-the propagation of long waves onto a shelf Goring, D.G.
  6. J. Waterway, Port, Coastal and Ocean Engrg v.120 no.1 Charcteristics of solitary wave breaking induced by creakwaters Grilli, S.T.;Losada, M.;Martin, F.L.
  7. J. Fluid Mech. v.95 Surf and run-up ona beach: a uniform bore Hibberd, S.;Peregrine, D.H.
  8. J. Waterway, Port Coastal and Ocean Engrg. v.120 no.6 Surf-similarity parameters for breaking solitary-wave runup Kobayashi, N.;Karjadi, E.A.
  9. J. Waterway, Port Coastal and Ocean Engrg. v.115 no.5 Wave transmission over submerged breakwaters Kobayashi, N.;Wurjanto
  10. J. Waterway, Port Coastal and Ocean Engrg. v.113 no.3 Wave reflection and run-up on rough slopes Kobayashi, N.;Otta, A.K.;Roy, I
  11. J. Waterway, Port Coastal and Ocean Engrg. v.118 no.2 Armor stability on submerged breakwaters Losada, M.;Kobayashi, N.;Martin, F.L.
  12. Difference Methods for Initial Value Problems Richtmyer, R.D.;Morton, E.W.
  13. Tech. Rept. No. 80-1, U.S. Army Coast. Engrg. Res. Ctr. Two-dimensional tests of wave transmission and reflection characteristics of laboratory breakwaters Seelig, W.N.
  14. U.S. Army Coast. Engrg. Res. Ctr. Shore Protection Manual
  15. J. Fluid Mech. v.185 The runup of solitary waves Synolakis, C.E.
  16. J. Waterway, Port, Coastal and Ocean Engrg. v.121 no.6 Modeling of breaking and nonbreaking long-wave evolution and runup using VTCS-2 Titov, V.V.;Synolakis, C.E.
  17. J. Waterway, Port, Coastal and Ocean Engrg. v.120 no.1 Stability and transmission at low-crested rubble mound structures Van der Meer, J.W.;Daemen, F.R.
  18. J. Waterway, Port, Coastal and Ocean Engrg. v.121 no.5 Wave interaction with berm breakwaters Van Gent, M.R.A.
  19. Coastal Engrg. v.15 The run-up of nonbreaking and breaking solitary waves Zelt, J.A.