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Wave Forces Acting on a Cylindrical Aquaculture Fish Cage

원통형 양식시설물에 작용하는 파랑하중

  • Cho, Il-Hyoung (Department of Ocean System Engineering, Jeju National University)
  • 조일형 (제주대학교 해양시스템공학과)
  • Received : 2010.10.20
  • Accepted : 2011.01.03
  • Published : 2011.02.28

Abstract

In this paper, the wave forces on a cylindrical aquaculture fish cage, which consists of the porous mesh with the uniform porosity, are analyzed using matched eigenfunction expansion method. The boundary condition on the porous net is derived based on the Darcy's law, which implies that the velocity of the fluid passing through the net is linearly proportional to the pressure difference between two sides of the net. The wave forces and wave responses are investigated by changing the porous parameter of porous net as well as the submerged position (floating type, bottom-mounted type) of an aquaculture fish cage. It is found that the wave forces on a bottom-mounted type are largely decreased compared with that on a floating type. Also, the porosity of the netting structure plays an important role in reducing the wave forces and the wave elevation in the vicinity of an aquaculture fish cage.

본 연구에서는 일정한 공극율을 갖는 투과성 그물망으로 이루어진 원통형 양식시설물에 작용하는 파랑하중을 고유함수전개법을 사용하여 해석하였다. 그물망에서의 경계조건식으로 그물망을 통과하는 속도값은 그물망 전후의 압력차에 선형적으로 비례한다는 Darcy의 법칙을 적용하였다. 그물망의 공극율 계수와 양식시설물의 잠긴 위치(부상식, 착저식)를 변화시키면서 양식시설물에 작용하는 파랑하중과 파도응답을 살펴보았다. 착저식 양식시설물에 작용하는 파랑하중이 부상식과 비교하여 크게 감소하며, 그물망의 공극율이 양식시설물의 파랑하중과 양식시설물 주변의 파형을 줄이는데 중요한 역할을 함을 밝혔다.

Keywords

References

  1. 조일형 (2002). 수평형 타공판의 소파특성. 한국해안.해양공학회지, 14(4), 265-273.
  2. 조일형 (2010). 투과성 이중 반원통 구조물에 의한 파 차단성능. 한국해안.해양공학회지, 22(1), 10-17.
  3. Cho, I.H. and Kim, M.H. (2008). Wave absorbing system using inclined perforated plates. J. Fluid Mech., 608, 1-20.
  4. Chwang, A.T. (1983). A porous wavemaker theory. J. Fluid Mech., 132, 395-406. https://doi.org/10.1017/S0022112083001676
  5. Chwang, A.T. and Wu, J. (1994). Wave scattering by submerged porous disk. J. Engrg. Mech., 120, 2575-2587. https://doi.org/10.1061/(ASCE)0733-9399(1994)120:12(2575)
  6. Evans, D. V. and Porter, R. (1996). Hydrodynamic characteristics of a thin rolling plate in finite depth of water. Applied Ocean Research, 18, 215-228.
  7. Lader, PF., Jensen, A., Sveen, J.K., Fredheim, A., Enerhaug, B. (2007). Experimental investigation of wave forces on net structure. Applied Ocean Research, 29, 112-127. https://doi.org/10.1016/j.apor.2007.10.003
  8. Lee, C.W., Kim, Y.B., Lee, G.H., Choe, M.Y., Lee, M.K., Koo, K.Y. (2008). Dynamic simulation of a fish cage system subjected to currents and waves. Ocean Engineering, 35, 1521-1532. https://doi.org/10.1016/j.oceaneng.2008.06.009
  9. Wang, K.H. and Ren, X. (1994). Wave interaction with a concentric porous cylinder system. Ocean Engineering, 21, 343-360. https://doi.org/10.1016/0029-8018(94)90009-4
  10. Zhao, F., Bao, W., Kinoshita, T., Itakura, H. (2010). Interaction of waves and porous cylinder with an inner horizontal porous plate. Applied Ocean Research, 32, 252-259. https://doi.org/10.1016/j.apor.2009.11.003