On the Calculation of Irregular Wave Reflection from Perforated-Wall Caisson Breakwaters Using a Regular Wave Model

규칙파 모델을 이용한 유공케이슨 방파제로부터의 불규칙파 반사율 산정에 대하여

  • 서경덕 (서울대학교 지구환경시스템공학부 및 해양시스템공학연구소) ;
  • 손상영 (현대건설주식회사 기술연구소 토목기술부)
  • Published : 2003.03.01

Abstract

In this paper we examine several methods tor calculating the reflection of irregular waves from a perforated-wall caisson breakwater using a regular wave model. The first method is to approximate the irregular waves as a regular wave whose height and period are the same as the root-mean-squared wave height and significant wave period, respectively, of the irregular waves. The second is to use the regular wave model, repeatedly, for each frequency component of the irregular wave spectrum. The wave period is determined according to the frequency of the component wave, and the root-mean-squared wave height is used for all the frequencies. The third method is the same as the second one except that the wave height corresponding to the energy of each component wave is used. Comparison with experimental data from previous authors shows the second method is the most adequate, giving reasonable agreement in both frequency-averaged reflection coefficients and reflected wave spectra.

본 논문에서는 규칙파 모델을 이용하여 유공케이슨 방파제로부터의 불규칙파의 반사를 계산하는 몇 가지 방법들을 검토한다. 첫 번째 방법은 불규칙파를 파고 및 주기가 각각 불규칙파의 제곱평균제곱근 파고 및 유의주기와 같은 규칙파로 근사하는 것이다. 두 번째는 불규칙파 스펙트럼의 각 주파수 성분에 대하여 규칙파 모델을 반복적으로 사용하는 것이다. 파의 주기는 성분파의 주파수에 따라 결정되며, 모든 주파수에 대해서 제곱평균제곱근 파고를 사용한다. 세 번째 방법은 두 번째 방법과 같으나, 각 성분파의 에너지에 해당하는 파고를 사용한다. 이전 연구자들의 실험 결과와 비교해 본 결과, 두 번째 방법이 가장 타당하며, 주파수 평균 반사율과 반사파 스펙트럼 모두 실험치와 양호한 일치를 보였다.

Keywords

References

  1. Coastal Engineering v.18 A mathematical model of a slotted wavescreen breakwater Bennett,G.S.;Mclver,P.;Smallman,J.V.
  2. Journal of Waterway, Port, Coastal and Ocean Engineering v.118 Hydraulic design of perforated breakwaters Fugazza,M.;Natale,L.
  3. Random Seas and Design of Maritime Structures(2nd ed.) Goda,Y.
  4. Dock Harbour Authority v.ⅩⅡ no.486 A perforated vertical wall breakwater Jarlan,G.E.
  5. Journal of Waterway, Port, Coastal and Ocean Engineering v.119 Scattering of water waves by vertical cylinders Kakuno,S.;Liu,P.L.F.
  6. Proceedings of 23rd International Conference on Coastal Engineering Scattering of water waves by vertical cylinders with a backwall Kakuno,S.;Oda,K.;Liu,P.L.F.
  7. Proceedings of International Conference on Coastal Structures v.79 Analysis of breakwaters having two porous walls Kondo,H.
  8. Proceedings of 11th International Conference on Coastal Engineering Experimental study on a fixed perforated breakwater Marks,M.;Jarlan,G.E.
  9. Journal of Waterways, Harbors and Coastal Engineering Division, ASCE v.100 Quadratic loss and scattering of long waves Mei,C.C.;Liu,P.L.F.;Ippen,A.T.
  10. Journal of Korean Society of Coastal and Ocean Engineers v.5 Hydraulic experiments for the reflection characteristics of perforated break-waters Park,W.S.;Chun,I.S.;Lee,D.S.
  11. Coastal Engineering Journal v.42 Scattering of irregular waves by vertical cylinders Park,W.S.;Kim,B.H.;Suh,K.D.;Lee,K.S.
  12. Journal of Korean Society of Coastal and Ocean Engineers v.4 Separation technique of incident and reflected waves using least squares method Park,W.S.;Oh,Y.M.;Chun,I.S.
  13. Numerical Recipes in FORTRAN:The Art of Scientific Computing(2nd ed.) Press,W.H.;Teukolsky,S.A.;Vetterling,W.T.;Flannery,B.P.
  14. Master thesis Calculation of irregular wave reflection from perforated-wall caisson breakwaters using a regular wave model Son,S.Y.
  15. Coastal Engineering v.44 Reflection of irregular waves from perforated-wall caisson breakwaters Suh,K.D.;Choi,J.C.;Kim,B.H.;Park,W.S.;Lee,K.S.
  16. Coastal Engineering v.26 Wave reflection from perforated-wall caisson breakwaters Suh,K.D.;Park,W.S.
  17. Proceedings of Hydro-Port94 Wave pressure on a perforated caisson Takahashi,S.;Shimosako,K.
  18. Proceedings of Hydro-Port94 A proposal of impulsive pressure coefficient for the design of composite breakwaters Takahashi,S.;Tanimoto,K.;Shimosako,K.
  19. An experimental investigation of wave reflection, overtopping and wave forces for several types of breakwaters and sea walls no.246 Tanimoto,K.;Haranaka,S.;Takahashi,S.;Komatsu,K.;Todoroki,M.;Osato,M.
  20. Proceedings of 11th International Conference on Coastal Engineering Model studies of a perforated breakwater Terret,F.L.;Osorio,J.D.C.;Lean,G.H.