International Journal of Ocean System Engineering

Korean Society of Ocean Engineers (한국해양공학회)
권호 표지
DOI QR코드

DOI QR Code

Experimental Study of Flow Fields around a Perforated Breakwater

  • Ariyarathne, H.A. Kusalika S. (Zachry Department of Civil Engineering, Texas A&M University) ;
  • Chang, Kuang-An (Zachry Department of Civil Engineering, Texas A&M University) ;
  • Lee, Jong-In (Department of Civil Engineering, Chonnam National University) ;
  • Ryu, Yong-Uk (Plant & Environment Research Division, R&D Center, Hyundai Engineering & Construction)
  • Received : 2011.12.17
  • Accepted : 2012.02.19
  • Published : 2012.02.29
Download PDF
⟨ Previous Next ⟩

Abstract

This study investigates flow fields and energy dissipation due to regular wave interaction with a perforated vertical breakwater, through velocity data measurement in a two-dimensional wave tank. As the waves propagate through the perforated breakwater, the incoming wave energy is reflected back to the ocean, dissipated due to very turbulent flows near the perforations and inside the chamber, and transmitted through the perforations of the breakwater. This transmitted energy is further reduced due to the presence of the perforated back wall. Hence most of the energy is either reflected or dissipated in the vicinity of the structure, and only a small amount of the incoming wave energy is transmitted through the structure. In this study, particle image velocimetry (PIV) technique was employed to measure two-dimensional instantaneous velocity fields in the vicinity of the structure. Measured velocity data was treated statistically, and used to calculate mean flow fields, turbulence intensity and turbulent kinetic energy. For investigation of the flow pattern, time-averaged mean velocity fields were examined, and discussed using the cross-sections through slot and wall for comparison. Flow fields were obtained and compared for various cases with different regular wave conditions. In addition, turbulent kinetic energy was estimated as an approach to understand energy dissipation near the perforated breakwater. The turbulent kinetic energy was distributed against wave height and wave period to see the dependence on wave conditions.

Keywords

References

  1. E-H. Aoul and E. Lambert, Tentative new formula for maximum horizontal wave forces acting on perforated caisson, J. of Waterway Port Coastal and Ocean Eng., 129 (1) (2003) 34-40. https://doi.org/10.1061/(ASCE)0733-950X(2003)129:1(34)
  2. G.S. Bennet, P. McIver, and J.V. Smallman, A mathematical model of a slotted wavescreen breakwater, Coast. Eng., 18 (1993) 231-249. https://doi.org/10.1016/0378-3839(92)90021-L
  3. K. Hagiwara, Analysis of upright structure for wave dissipation using integral equation, Proc. Coast Eng., (1984) 2810-2826.
  4. M. Isaacson, S. Premasiri, and G. Yang, Wave interactions with vertical slotted barrier, J. of Waterway Port Coastal and Ocean Eng., 124 (3) (1998) 118-126. https://doi.org/10.1061/(ASCE)0733-950X(1998)124:3(118)
  5. G.E. Jarlan, A perforated vertical wall breakwater, The Dock and Harbour Authority, 41 (1961) 394-398.
  6. H. Kondo, Analysis of breakwaters having two porous walls, Proc. Coastal Structures, (1979) 962-977.
  7. Y. Li, G. Dong, H. Liu, and D. Sun, The reflection of oblique incident waves by breakwaters with double-layered perforated wall, Coastal Eng., 50 (2003) 47-60. https://doi.org/10.1016/j.coastaleng.2003.08.001
  8. I.J. Losada, M.A. Losada, and A. Baquerizo, An analytical method to evaluate the efficiency of porous screens as wave dampers, Applied Ocean Res., 15 (1993) 207-215.
  9. V. Mallayachari, and V. Sundar, Reflection characteristics of permeable seawalls, Coastal Eng., 23 (1994) 135-150. https://doi.org/10.1016/0378-3839(94)90019-1
  10. N. Mori and K-A. Chang, Introduction to MPIV, User manual and program available online at http://sauron.civil.eng.osakacu.ac.jp/-mori/softwares/mpiv/ (2003)
  11. S. Requejo, C. Vidal, and I.J. Losada, Modelling of wave loads and hydraulic performance of vertical permeable structures, Coastal Eng., 46 (2002) 249-276. https://doi.org/10.1016/S0378-3839(02)00072-8
  12. K.D. Suh and W.S. Park, Wave reflection from perforated-wall caisson breakwaters, Coastal Eng., 26 (1995) 177-193. https://doi.org/10.1016/0378-3839(95)00027-5
  13. K.D. Suh, J.C. Choi, B.H. Kim, W.S. Park, and K.S. Lee, Reflection of irregular waves from perforated-wall caisson breakwaters, Coastal Eng., 44 (2001) 141-151. https://doi.org/10.1016/S0378-3839(01)00028-X
  14. K.D. Suh, J.K. Park, and W.S. Park, Wave reflection from partially perforated-wall caisson breakwater, Coastal Eng., 33 (2006) 264-280.
  15. S.W. Twu and D.T. Lin, On a highly effective wave absorber, Coastal Eng., 15 (1991) 389-405. https://doi.org/10.1016/0378-3839(91)90018-C
  16. S. Urashima, K. Ishizuka, and H. Kondo, Energy dissipation and wave force at slotted wall, Proc. 20th Coastal Engineering Conf., 3 (1986) 2344-2352.
  17. S. Zhu and A.T. Chwang, Investigations on the reflection behaviour of a slotted seawall, Coastal Eng., 43 (2001) 93-104. https://doi.org/10.1016/S0378-3839(01)00008-4