Journal of the Society of Naval Architects of Korea (대한조선학회논문집)

The Society of Naval Architects of Korea (대한조선학회)
권호 표지
DOI QR코드

DOI QR Code

Theoretical Study on the Generation of Directional Extreme Waves

다방향 극한파 생성의 이론적 연구

  • 홍기용 (한국해양연구원 해양개발시스템연구본부) ;
  • 류슈쉐 (대련이공대학 해안해양공학국가중점연구실) ;
  • 홍석원 (한국해양연구원 해양개발시스템연구본부)
  • Published : 2002.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

Theoretical development to generate the directional extreme waves in model basin is established based on wave focusing method. The effects of associated parameters, such as the directional range, frequency width, and center frequency, are investigated in terms of wave focusing efficiency. The two different spectral models of constant wave amplitude and constant wave slope are applied to control the wave characteristics. The wave packets simulated by theory are compared with numerical results based on Boussinesq equation and FEM. Both controls of direction and frequency spectrum are essential to focus directional waves effectively. It is noticed that wave focusing ability depends on the frequency bandwidth of spectrum rather than center frequency, and both spectral models with same parameters result in the equivalent efficiency of wave focusing.

파랑집중 이론에 기초하여 모형시험수조에서 다방향 극한파를 생성하는 연구를 수행하였다. 파랑의 집중도에 대한 파향 범위, 주파수 폭, 중심 주파수 등의 영향을 고찰하였다. 등파고와 등기 울기 스펙트럼 모델에 의한 결과를 서로 비교하였으며, Boussinesq 방정식과 유한요소법에 기초한 수치해와 이론해를 또한 서로 비교하였다. 효율적인 파랑집중을 위해서는 파향과 주파수 모두를 효과적으로 제어하는 것이 필수적이다. 파랑집중도는 중심주파수 보다는 주파수 폭에 좌우되며, 동일한 조건하에서 두 스펙트럼 모델은 동등한 정도의 파랑집중 효율을 나타낸다.

Keywords

References

  1. Beji, S. & Nadaoka, K., 1996 'A formal derivation and numerical modeling of the improved Boussinesq equations for varying depth', Ocean Eng., 23(8), 691-704 https://doi.org/10.1016/0029-8018(96)84408-8
  2. Biesel, F., 1954 'Wave machines', Proc. 1st Conf. on Ships and Waves, 288-304
  3. Chan, E.S. & Melville, W.K., 1988 'Deep water plunging wave pressures on a vertical plane wall', Proc. of the Royal Society, A417, 95-131
  4. Johannessen, T.B. 1997 'The effect of directionality on the nonlinear behavior of extreme transient ocean waves', Ph.D thesis, University of London
  5. Kway H.L., Loh Y.S. & Chan E.S., 1998 'Laboratory study of deep-water breaking waves', Ocean Eng., 25(8), 657-676 https://doi.org/10.1016/S0029-8018(97)00039-5
  6. Larsen, J. & Dancy, H., 1983 'Open boundaries in short wave simulationa new approach', Coastal Eng., 7, 285-297 https://doi.org/10.1016/0378-3839(83)90022-4
  7. Ramberg, S.E. & Griffin, O.M., 1987 'Laboratory study of steep and breaking deep water waves', J. Waterway, Port, Coastal and Ocean Eng., 113, 493-506 https://doi.org/10.1061/(ASCE)0733-950X(1987)113:5(493)
  8. Rapp, R.J. & Melville, W.K., 1990 'Laboratory measurements of deep-water breaking waves', Transactions Philosophical of the Royal Society of London, A331, 735-800
  9. She, K., Greated, C.A., & Easson, W.J., 1994 'Experimental study of three-dimensional wave breaking', J. waterway, Port, Coastal, and Ocean Eng., 120, 20-36 https://doi.org/10.1061/(ASCE)0733-950X(1994)120:1(20)
  10. Skyner, D.J., Gray, C., & Greated, C.A., 1990 'A comparison of time-stepping numerical predictions with whole-field flow measurement in breaking waves', Water Wave Kinematics, 491-508
  11. Su, M.Y., 1982 'Three dimensional deep water waves', J. Fluid Mech., 124, 73-108 https://doi.org/10.1017/S0022112082002419
  12. Takayama, T., 1984 'Theory of oblique waves generated by serpent type wave-maker', Coastal Engineering in Japan, 27, pp.1-19
  13. Takezawa, S. & Takekawa, M., 1976 'Advanced experimental techniques for testing ship models in transient water waves: Part I: The transient test technique on ship motions in waves', 11th Symposium on Naval Hydrodynamics, 23-35
  14. Takezawa, S. & Hirayama, T., 1976 'Advanced experimental techniques for testing ship models in transient water waves: Part II: The controlled transient water waves for using in ship motion tests', 11th Symposium on Naval Hydrodynamics, 37-54