Journal of Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회논문집)

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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Characteristics of Wave on Circular Breakwater of Double Array by Various Porous Coefficients among Circular Caissons

원형케이슨들간의 공극률 변화에 따른 2열 배치 원형방파제에 작용하는 파랑 특성 분석

  • Park, Min Su (Department of Infrastructure Safety Research, Korea Institute of Civil Engineering and Building Technology)
  • 박민수 (한국건설기술연구원 인프라안전연구본부)
  • Received : 2020.11.19
  • Accepted : 2020.12.04
  • Published : 2020.12.31
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Abstract

In order to increase the stability of existing breakwater, new caissons are installed on the back or the front of existing caissons. It is very important to evaluate wave force and wave run-up according to the change of porosity among caissons and the energy loss due to separation effects. In this study, we use the eigenfunction expansion method with Darcy's law, which describes the flow of a fluid through a porous plate, to analyze the characteristics of wave on circular breakwater of double array for various porous coefficients. To verify the numerical method, the comparison between present results and Sankarbabu et al. (2008) is made. The wave force and the wave run-up acting on each dual cylindrical caisson are calculated for various parameters by considering the energy loss and the change of porosity.

기존 케이슨방파제의 안정성을 높이기 위해 케이슨 전면 또는 후면에 추가로 신규 케이슨을 설치하여 보강하는 경우 박리에 의한 에너지 손실효과와 케이슨과 케이슨 사이의 공극률 변화에 따른 개별 원형케이슨에 작용하는 파력 및 파처오름 특성 평가는 중요하다. 본 연구에서는 고유함수전개법에 투과성판에서의 속도는 판 전후의 압력차에 선형적으로 비례한다는 Darcy의 법칙을 이용하여 원형케이슨들간의 공극률 계수 변화에 따른 2열 배치된 원형방파제에 작용하는 파랑 특성을 분석하였다. 수치해석의 신뢰성을 확보하기 위해 Sankarbabu et al.(2008)의 수치 해석결과와 비교를 수행하였으며, 다양한 변수에 따른 개별 이중 원형케이슨에 작용하는 파력 및 파처오름 특성을 나타내었다.

Keywords

Acknowledgement

본 연구는 해양수산과학기술진흥원의 안전한 항만 구축 및 관리기술 개발사업인 "재해안전항만 구축 기술개발(20180323)" 과제를 통해 수행된 연구결과 중 일부임을 밝히며, 연구비 지원에 감사드립니다.

References

  1. Cho, I.H. (2002). Wave absorbing characteristics of a horizontal submerged punching plate. Journal of Korean Society of Coastal and Ocean Engineers, 14(4), 265-273 (in Korean).
  2. Cho, I.H. (2003). Wave control by an array of n bottom mounted porous cylinders. Journal of Korean Society of Coastal and Ocean Engineers, 15(4), 232-241 (in Korean).
  3. Cho, I.H. (2004). Wave control by an array of porous dual cylindrical structures. Journal of Ocean Engineering and Technology, 18(5), 7-14 (in Korean).
  4. Isaacson, M., Premasiri, S. and Yang, G. (1998). Wave interactions with vertical slotted barrier. Journal of Waterway, Port, Coastal and Ocean Engineering, 124, 118-126. https://doi.org/10.1061/(ASCE)0733-950X(1998)124:3(118)
  5. Kim, M.H. (1993). Interaction of waves with N vertical circular cylinders. Journal of Waterway Port Coastal and Ocean Engineering, 119, 671-689. https://doi.org/10.1061/(ASCE)0733-950X(1993)119:6(671)
  6. Linton, C.M. and Evans, D.V. (1990). The interaction of waves with arrays of vertical circular cylinder. Journal of Fluid Mechanics, 215, 549-569. https://doi.org/10.1017/S0022112090002750
  7. Maniar, H.D. and Newman, J.N. (1997). Wave diffraction by a long array of cylinders. Journal of Fluid Mechanics, 339, 309-330. https://doi.org/10.1017/S0022112097005296
  8. Park, M.S. (2020). Wave structure interaction by installation of new circular caissons on old circular caisson breakwater. Journal of Korean Society of Coastal and Ocean Engineers, 32(5), 307-321 (in Korean). https://doi.org/10.9765/KSCOE.2020.32.5.307
  9. Park, M.S., Koo, W.C. and Choi, Y.R. (2010). Hydrodynamic interaction with an array of porous circular cylinders. International Journal of Naval Architecture and Ocean Engineering, 2, 146-154. https://doi.org/10.3744/JNAOE.2010.2.3.146
  10. Sankarbabu, K., Sannasiraj, S.A. and Sundar, V. (2007). Interaction of regular waves with a group of dual porous circular cylinders. Applied Ocean Research, 29, 180-190. https://doi.org/10.1016/j.apor.2008.01.004
  11. Sankarbabu, K., Sannasiraj, S.A. and Sundar, V. (2008). Hydrodynamic performance of a dual cylindrical caisson breakwater. Coastal Engineering, 55, 431-446. https://doi.org/10.1016/j.coastaleng.2007.12.007
  12. Vijayalakshmi, K. (2005). Hydrodynamics of a Perforated Circular Caisson Encircling a Vertical Cylinder. Ph.D Thesis, Indian Institute of Technology Madras, India.
  13. Wang, K.H. and Ren, X. (1994). Wave interaction with a concentric porous cylinder system. Ocean Engineering, 21(4), 343-360. https://doi.org/10.1016/0029-8018(94)90009-4
  14. Williams, A.N. and Li, W. (2000). Water wave interaction with an array of bottom-mounted surface-piercing porous cylinders. Ocean Engineering, 27, 840-866.
  15. Yu, X. (1995). Diffraction of water waves by porous breakwaters. Journal of Waterway, Port, Coastal and Ocean Engineering, 121, 275-282. https://doi.org/10.1061/(ASCE)0733-950X(1995)121:6(275)