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

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
권호 표지
DOI QR코드

DOI QR Code

Reflection of Porous Wave Absorber Using Quasi-linear Numerical Model

준선형 수치모델을 이용한 투과성 소파장치의 반사율

  • Ko, Chang-hyun (Faculty of Wind Energy Engineering, Jeju National University) ;
  • Cho, Il-Hyoung (Faculty of Ocean System Engineering, Jeju National University)
  • 고창현 (제주대학교 풍력공학부) ;
  • 조일형 (제주대학교 해양시스템공학과)
  • Received : 2017.11.24
  • Accepted : 2018.01.02
  • Published : 2018.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

In present study, we suggested the quasi-linear model that linearizes the quadratic drag representing the energy loss across the porous plate. The quasi-linear model was solved by Boundary Element Method (BEM) for development of the porous wave absorber suitable for 2-D wave tank. The drag coefficient at the porous plate was newly obtained through comparison of experimental results. It is found that the porous wave absorber with porosity 0.1, submergence depth d/h = 0.1, and inclined angle $10^{\circ}{\leq}{\theta}{\leq}20^{\circ}$ shows the effective wave absorption. Using the developed quasi-linear numerical model, the optimal design of various types of a porous wave absorber will be applied.

본 연구에서는 투과성 판을 통과하면서 발생하는 에너지 손실효과를 나타내는 비선형 항력 항을 등가 선형화기법으로 선형화시킨 준선형 모델을 제안하였다. 이 모델을 경계요소법(Boundary Element Method)으로 풀어 2차원 조파수조의 투과성 소파장치를 개발에 활용하였다. 투과성 판에서의 항력계수는 수리 모형실험 결과와 비교를 통해 새롭게 구하였다. 공극률 0.1, 잠긴 깊이 d/h = 0.1, 경사각도 $10^{\circ}{\leq}{\theta}{\leq}20^{\circ}$를 갖는 투과성 소파장치가 전반적으로 우수한 소파성능을 보였다. 개발된 준선형 수치모델은 앞으로 다양한 형태의 투과성 소파장치의 최적 설계에 활용될 것이다.

Keywords

References

  1. Bennett, G.S., McIver, P. and Smallman, J.V. (1992). A mathematical model of a slotted wavescreen breakwater. Coastal Engineering, 18, 231-249.
  2. Cho, I.H. and Hong, S.W. (2004). Development of a wave absorbing system using an inclined punching plate. Journal of Ocean Engineering and Technology, 18(1), 1-6 (in Korean).
  3. Cho, I.H. and Kim, M.H. (2008). Wave absorbing system using inclined perforated plates. Journal of Fluid Mechanics, 608, 1-20.
  4. Cho, I.H. and Kim, M.H. (2013). Transmission of oblique incident waves by a submerged horizontal porous plate. Ocean Engineering, 61, 56-65. https://doi.org/10.1016/j.oceaneng.2012.12.044
  5. Crowley, S. and Porter, R. (2012). The effect of slatted screens on waves. Journal of Engineering Mathematics, 76, 53-76.
  6. Goda, Y. and Suzuki, Y. (1976). Estimation of incident and reflected waves in random wave experiments. Proceedings of 15th Intl. Conf. on Coastal Engrg., ASCE, Honolulu, United States, 828-845.
  7. Linton, C.M. (2001). The finite dock problem. Zeitschrift für Angewandte Mathematik und Physik, 52(4), 640-656. https://doi.org/10.1007/PL00001565
  8. Linton, C.M. and Evans, D.V. (1991). Trapped modes above a submerged horizontal plate. The Quarterly Journal of Mechanics and Applied Mathematics, 44(3), 487-506. https://doi.org/10.1093/qjmam/44.3.487
  9. Liu, Y., Li, Y.C. and Teng, B. (2008). Wave motion over a submerged break-water with an upper horizontal porous plate and a lower horizontal solid plate. Ocean Engineering, 35, 1588-1596.
  10. Liu, Y. and Li, Y.C. (2011). An alternative analytical solution for water-wave motion over a submerged horizontal porous plate. Journal of Engineering Mathematics, 69(4), 385-400. https://doi.org/10.1007/s10665-010-9406-8
  11. Mansard, E.P.D. and Funke, E.R. (1980). The measurement of incident and reflected spectra using a least squares methods. Proceedings of 17th Intl. Conf. on Coastal Engrg., ASCE, Sydney, Australia, 154-172.
  12. McIver, M. (1985). Diffraction of water waves by a moored, horizontal, flat plate. Journal of Engineering Mathematics, 19(4), 297-320. https://doi.org/10.1007/BF00042875
  13. Mei, C.C., Liu, P.L.F. and Ippen, A.T. (1974). Quadratic loss and scattering of long waves. Journal of the Waterways, Harbors and Coastal Engineering Division, 100(3), 217-239.
  14. Molin, B. and Remy, F. (2013). Experimental and numerical study of the sloshing motion in a rectangular tank with a perforated screen. Journal of Fluids and Structures, 43, 463-480.
  15. Neelamani, S. and Gayathri, T. (2006). Wave Interaction with twin plate wave barrier. Ocean Engineering, 33, 495-516. https://doi.org/10.1016/j.oceaneng.2005.03.009
  16. Patarapanich, M. and Cheong, H.F. (1989). Reflection and transmission characteristics of regular and random waves from a submerged horizontal plate. Coastal Engineering, 13(2), 161-182. https://doi.org/10.1016/0378-3839(89)90022-7
  17. Shore Protection manual (SPM) (1984). Vol I; Coastal Engineering Research Center; US Army Corps of Engineers; Washington; Waterways Experiment Station.
  18. Siew, P.F. and Hurley, D.G. (1977). Long surface waves incident on a submerged horizontal plate. Journal of Fluid Mechanics, 83(1), 141-151. https://doi.org/10.1017/S0022112077001098
  19. Wu, J., Wan, Z. and Fang, F. (1998). Wave reflection by a vertical wall with a horizontal submerged porous plate. Ocean Engineering, 25(9), 767-779. https://doi.org/10.1016/S0029-8018(97)00037-1
  20. Yoon, S.B., Lee, J.I., Nam, D.H. and Kim, S.H. (2006). Energy loss coefficient of waves considering thickness of perforated wall. Journal of Korean Society of Coastal and Ocean Engineers, 18(4), 321-328 (in Korean).
  21. Yueh, C.Y. and Chuang S.H. (2009). Wave scattering By a submerged porous plate wave absorber. Proceedings of 19th Intl. Offshore and Polar Engrg. Conf., ISOPE, Osaka, Japan.