DOI QR코드

DOI QR Code

Analysis of Bragg Reflection with Two-Dimensional Finite Element Method

2차원 유한요소법을 이용한 파랑의 Bragg반사 해석

  • 조용식 (한양대학교 공과대학 토목공학과) ;
  • 정우창 (홍익대학교 공과대학 토목공학과)
  • Published : 2002.12.01

Abstract

In this study, a finite element model is employed to simulate the diffraction of waves caused by a change of water depths. The model is firstly applied to the estimation of reflection coefficients of monochromatic waves over a sinusoidally varying topography. Predicted coefficients are compared with those of the eigenfunction expansion method and laboratory measurements. A good agreement is observed. The model is then used to investigate effects of heights of bottom topography and number of ripples on variation of reflection coefficients of monocromatic water waves.

본 연구에서는 유한요소법을 이용하여 수심의 변화에 의해 발생되는 파랑의 회절에 대해 수치적 모의실험을 수행하였다. 본 모형은 정현파형 지형을 통과하는 단조파의 반사율을 계산하는데 적용되었다. 계산된 반사율은 고유 함수전개법에 의한 결과와 수리모형실험에 의한 관측결과와 비교하여 본 해석법을 검증하였으며, 이로부터 정현파형 지형의 진폭과 사련의 수의 변화에 대한 반사율의 변화에 적용하여 그의 특성을 조사하였다.

Keywords

References

  1. 김영택, 조용식, 이정규 (2000). '2차원 경계요소법을 이용한 Bragg반사 해석.' 한국수자원학회논문집, 한국수자원학회, 제33권, 제6호, pp. 805-814
  2. 조용식, 이종인, 이정규, 윤태훈 (1995). 'Bragg reflection of shallow-water waves.' 대한토목학회논문집, 대한토목학회, 제15권, 제6호, pp. 1823-1832
  3. 조용식, 이창훈 (1998). '수심이 변하는 지형을 통과하는 파랑의 반사율과 통과율 산정.' 대한토목학회논문집, 대한토목학회, 제18권, 제II-4호, pp. 351-358
  4. Bailard, J., DeVries, J.W., and Kirby, J.T. (1992). 'Considerations in using Bragg reflection for storm erosion protection.' Journal of Waterway, Prot, Coastal and Ocean Engineering, ASCE, Vol. 118, pp. 62-74 https://doi.org/10.1061/(ASCE)0733-950X(1992)118:1(62)
  5. Cho, Y.-S. and Lee, C.H. (2000). 'Resonant reflection of waves over sinusiodally warying topographies.' Journal of Coastal Research, Vol. 16, No. 9, pp. 870-876
  6. Dalrymple R.A. and Kirby, J.T. (1986). 'Water waves over ripples.' Journal of Waterway, Prot, Coastal and Ocean Engineering, ASCE, Vol. 112, pp. 309-319 https://doi.org/10.1061/(ASCE)0733-950X(1986)112:2(309)
  7. Davies, A.G. and Heathershaw, A.D. (1984). 'Surface-wave propagation over sinusoidally varying topography.' Journal of Fluid Mechanics, Vol. 144, pp. 417-443 https://doi.org/10.1017/S0022112084001671
  8. Devillard, P., Dunlop, F. and Souillard, B. (1988). 'Localization of gravity waves on a channel with a random bootom.' Journal of Fluid Mechanics, Vol. 186, pp. 521-538 https://doi.org/10.1017/S0022112088000254
  9. Guazzelli, E., Rey, V. and Belzons, M. (1992). 'Higher-order Bragg reflection of gravity surface waves by periodic beds.' Journal of Fluid Mechanics, Vol. 245, pp. 301-317 https://doi.org/10.1017/S0022112092000478
  10. Hara, T. and Mei, C.C. (1987). 'Brag reflection of surface waves by periodic bars: theory and experiment.' Journal of Fluid Mechanics, Vol. 178, pp. 221-241 https://doi.org/10.1017/S0022112087001198
  11. Lamberti, A. and Mancinelli, A. (1997). 'Italian experience on submerged of beach deffence structures.' Proceedings of 25th Internatinal Conference on Coastal Engineering, Orlando, USA, pp. 2352-2365
  12. Lee, C.H., Park, W.-S., Cho, Y.-S. and Suh, K.D. (1998). 'Hyperbolic mild-slope equations extended to account for rapidly varying topography.' Coastal Engineering, Vol. 34, pp. 243-257 https://doi.org/10.1016/S0378-3839(98)00028-3
  13. Liu, P.L.-F. and Cho, Y.-S. (1993). 'Bragg reflection of infragravity waves by sandbars.' Journal of Geophysical Research, Vol. 98, pp. 22733-22741 https://doi.org/10.1029/93JC02350
  14. Mei, C. C. and Liu, P.L.-F. (1993). 'Surface waves and coastal dynamics.' Annual Review of Fliod Mechanics, Vol. 25, pp. 215-240 https://doi.org/10.1146/annurev.fl.25.010193.001243
  15. O'Hare, T.J. and Davies, A.G. (1992). 'A new model for surface-wave propagation over undulating topography.' Coastal Engineering, Vol. 18, pp. 251-266 https://doi.org/10.1016/0378-3839(92)90022-M
  16. Press, W.H., Flannery, B.P., Teukolsky, S.A. and Vetterling, W.T. (1992). Numerical Recipes in Fortran, 2nd edition, Cambridge University Press
  17. Tomasicchio, U. (1997). 'Submerged breakwaters for the defence of the shoreline at Ostia field experiemces, comparison.' Proceedings of 25th International Conference on Coastal Engineering, Orlando, USA, pp. 2404-2417
  18. Zienkiewicz, O.C. and Taylor, R.L. (1989). The Finite Element Method. McGraw-Hill International Editions