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Nonlinear Irregular Waves-current Interaction on Flow Fields with Wave Breaking around Permeable Submerged Breakwater

투과성잠제 주변에서 쇄파를 동반한 불규칙파-흐름장의 상호작용

  • Lee, Kwang-Ho (Dept. of Energy and Plant Eng., Catholic Kwandong University) ;
  • Bae, Ju-Hyun (Dept. of Civil and Environmental Eng., Graduate School, Korea Maritime and Ocean University) ;
  • An, Sung-Wook (Dept. of Civil and Environmental Eng., Graduate School, Korea Maritime and Ocean University) ;
  • Kim, Do-Sam (Dept. of Civil Eng., Korea Maritime and Ocean Univ.)
  • 이광호 (가톨릭관동대학교 에너지플랜트공학과) ;
  • 배주현 (한국해양대학교 대학원 토목환경공학과) ;
  • 안성욱 (한국해양대학교 대학원 토목환경공학과) ;
  • 김도삼 (한국해양대학교 건설공학과)
  • Received : 2018.02.08
  • Accepted : 2018.02.20
  • Published : 2018.04.30

Abstract

In this study, the nonlinear interaction of irregular waves with wave breaking and currents around permeable submerged breakwater was investigated with the aid of olaFlow model which is open source CFD software published under the GPL license. The irregular wave performance of olaFlow applied in this study was verified by comparing and evaluating the target frequency spectrum and the generated frequency spectrum for applicability to irregular waves. Based on the applicability of this numerical model to irregular wave fields, in the coexistence fields of irregular waves and currents, the characteristics of wave height, frequency spectrum, breaking waves, averaged velocity and turbulent kinetic energy around porous submerged breakwater with the respect to the beach type and current direction versus wave propagation were carefully investigated. The numerical results revealed that the shape of wave breaking on the crown of the submerged breakwater and the formation of the mean flow velocity around the structure depend greatly on the current directions and the type of the beach. In addition, it was found that the wave height fluctuation due to the current direction with respect to the wave propagation is closely related to the turbulent kinetic energy.

본 연구는 공중사용허가서(오픈소스 기반) 라이선스 기반의 olaFlow를 적용하여 투과성잠제 주변에서 쇄파를 동반한 불규칙파와 흐름장의 비선형 상호작용을 고찰하였다. 본 연구에서 적용한 olaFlow의 불규칙파랑의 조파성능은 목표주파수스펙트럼과 조파파랑의 주파수스펙트럼을 비교 검토하여 불규칙파랑의 적용성을 검증하였다. 이로부터 지금까지 거의 검토되지 않은 불규칙파와 흐름의 공존장에 설치된 투과성잠제에 대해 배후경사면을 모래 혹은 자갈로 고려한 경우 흐름방향 등의 변화에 따른 잠제 주변에서 파고, 주파수스펙트럼, 쇄파, 평균유속 및 난류운동에너지 등의 변동특성을 면밀히 검토하였다. 수치해석결과로부터 투과성잠제의 천단상에서 발생하는 쇄파의 형태 및 평균유속의 형성은 흐름방향 및 배후사면의 형태에 따라 좌우됨을 알 수 있었다. 또한, 흐름방향에 따른 파고의 변화는 난류운동에너지와 밀접한 관계를 가지는 것 등의 중요한 사실을 확인할 수 있었다.

Keywords

References

  1. Baddour, R.E. and Song, S. (1990). On the interaction between wave and currents. Ocean Engineering, 17(1), 1-21. https://doi.org/10.1016/0029-8018(90)90011-T
  2. Garcia, N., Lara, J.L. and Losada, I.J. (2004). 2-D numerical analysis of near-field flow at low-crested permeable breakwters. Coastal Engineering, 51, 991-1020. https://doi.org/10.1016/j.coastaleng.2004.07.017
  3. Goda, Y. (2000). Random seas and design of maritime structures, World Scientific Publishing, Singapore.
  4. Goda, Y. (1988). Statistical variability of sea state parameters as a function of wave spectrum. Coastal Engineering in Japan, JSCE, 31(1), 39-52. https://doi.org/10.1080/05785634.1988.11924482
  5. Higuera, P., Losada, I.J. and Lara, J.L. (2015). Three-dimensional numerical wave generation with moving boundaries. Coastal Engineering, 101, 35-47. https://doi.org/10.1016/j.coastaleng.2015.04.003
  6. Isaacson, M. and Cheung, K.F. (1993). Time-domain solution for wave-current interactions with a two-dimensional body. Applied Ocean Research, 15(1), 39-52. https://doi.org/10.1016/0141-1187(93)90031-R
  7. Iwata, K., Kim, D.S., Asai, M. and Shimoda, M. (1990). Wave breaking on submerged floating structure. Proceedings of Coastal Engineering, JSCE, 37, 604-608 (in Japanese). https://doi.org/10.2208/proce1989.37.604
  8. Jensen, B., Jacobsen, N.G. and Christensen, E.D.(2014). Investigations on the porous media equations and resistance coefficients for coastal structures. Coastal Engineering, 84, 56-72. https://doi.org/10.1016/j.coastaleng.2013.11.004
  9. Lara, J.L., Garcia, N. and Losada, I.J. (2006). RANS modelling applied to random wave interaction with submerged permeable structures. Coastal Engineering, 53, 395-417. https://doi.org/10.1016/j.coastaleng.2005.11.003
  10. Lee, K.H., Bae, J.H., An, S.W., Kim, D.S. and Bae, K.S. (2016). Numerical analysis on wave characteristics around submerged breakwater in wave and current coexisting field by OLAFOAM. Journal of Korean Society of Coastal and Ocean Engineers, 28(6), 332-349 (in Korean). https://doi.org/10.9765/KSCOE.2016.28.6.332
  11. Lee, K.H., Bae, J.H., An, S.W., Kim, D.S. and Bae, K.S. (2016). Numerical analysis on wave characteristics around submerged breakwater in wave and current coexisting field by OLAFOAM. Journal of Korean Society of Coastal and Ocean Engineers, 28(6), 332-349 (in Korean). https://doi.org/10.9765/KSCOE.2016.28.6.332
  12. Lin, M.C. and Hsiao, S.S. (1994). Boundary element analysis of wave-current interaction around a large structure. Engineering Analysis with Boundary Elements, 14(4), 325-334. https://doi.org/10.1016/0955-7997(94)90062-0
  13. Liu, P.L.F., Lin, P., Chang, K.A. and Sakakiyama, T. (1999). Numerical modeling of wave interaction with porous structures. Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, 125(6), 322-330.
  14. Markus, D., Hojjat, M., Wüchner, R. and Bletzinger, K.U. (2013). A CFD approach to modeling wave-current interaction. International Journal of Offshore and Polar Engineering, 23(1), 29-32.
  15. Ranasinghe, R.S., Sato, S. and Tajima, Y. (2009). Modeling of waves and currents around porous submerged breakwaters. Coastal Dynamics, 12.
  16. Teles, M.J., Pires-Silva, A.A. and Benoit, M. (2013). Numerical modelling of wave current interactions at a local scale. Ocean Modelling, 68(0), 72-87. https://doi.org/10.1016/j.ocemod.2013.04.006
  17. Umeyama, M. (2009). Changes in turbulent flow structure under combined wave-current coexisting environment. Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, 131(5), 203-212. https://doi.org/10.1061/(ASCE)0733-950X(2005)131:5(203)
  18. Umeyama, M. (2011). Coupled PIV and PTV measurements of particle velocities and trajectories for surface waves following a steady current. Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, 137(2), 85-94. https://doi.org/10.1061/(ASCE)WW.1943-5460.0000067
  19. Zhao, R. and Faltinsen, O.M. (1988). Interaction between waves and current on a two-dimensional body in the free surface. Applied Ocean Research, 10(2), 87-99. https://doi.org/10.1016/S0141-1187(88)80035-X
  20. Zhang, J.S., Zhang, Y., Jeng, D.S., Liu, P.L.F. and Zhang, C. (2014). Numerical simulation of wave-current interaction using RANS solver. Ocean Engineering, 75, 157-164. https://doi.org/10.1016/j.oceaneng.2013.10.014

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