A Study on Flow and Creation and Dissipation of Vorticity around Rectangular Floating Breakwater

부방파제의 유동과 와의 생성 및 소멸에 관한 연구

  • Yoon, Jung-Sung (Department of Civil Engineering, Inje University) ;
  • Kim, Myoung-Kyu (Department of Civil Engineering, Inje University) ;
  • Jung, Kwang-Hyo (Department of Naval Architecture and Ocean Engineering, Dongeui University) ;
  • Kim, Ga-Ya (Department of Urban Engineering, Dongeui University)
  • Published : 2008.06.30

Abstract

In this study, flow and creation and dissipation of vorticity around rectangular floating breakwater is investigated both experimentally and numerically. The PIV system(Particle image velocimetry) is employed to obtain the velocity field in the vorticity of rectangular structure. The numerical model, combined with ${\kappa}-{\varepsilon}$ turbulence model and the VOF method based on RANS equation, is used to analyze the turbulence structure. In the results of this study, the vorticity is found around conner of rectangular structure at all time domain, and creation and dissipation of vorticity are closely related to wave period. Separation points of phase of vortex due to flow separation for longer period waves are faster then for shorter period waves.

Keywords

References

  1. 윤종성, 이민규, 정광효 (2005). '부유식 방파제의 설치에 따른 유동 및 난류구조 해석', 대한토목학회지 제25권, 제5B호, pp 375-383
  2. 윤종성 (1999). '성층수역에서 저층의 빈산소수의 혼합 및 용승현상에 관한 연구(II)', 대한토목학회지 제19권, 제II-5호, pp 575-583
  3. Chang, K.A., Hsu, T.J. and Liu, P.L.F. (2001). 'Vortex Generation and Evolution in Water Waves Propagating over a Submerged Rectangular Obstacle Part I. Solitary Waves', Coastal Eng., Vol 44, pp 13-36 https://doi.org/10.1016/S0378-3839(01)00019-9
  4. Chang, K.A., Hsu, T.J. and Liu, P.L.F. (2005). 'Vortex Generation and Evolution in Water Waves Propagating over a Submerged Rectangular Obstacle Part II. Cnoidal Waves', Coastal Eng., Vol 52, pp 257-283 https://doi.org/10.1016/j.coastaleng.2004.11.006
  5. Chen, H.C., Liu, P.L.F., Hsu, T.J., Chang, K.A. and Huang, E.T. (2002). 'Time-domain Simulation of Barge Capsizing by a Chimera Domain Decomposition Approach', 12th International Offshore and Polar Engineering Conference, KitaKyushu, Japan, May 26-31, pp 314-321
  6. Fugazza, M. and Natale, L. (1988). 'Energy Losses and Floating Breakwater Response', Journal of Waterway, Port, Coastal and Ocean Eng., Vol 114, No 2, pp 191-205 https://doi.org/10.1061/(ASCE)0733-950X(1988)114:2(191)
  7. Lin, P. and Liu, P.L.F. (1998). 'A Numerical Study of Breaking Waves in Surf Zone', J. Fluid Mech, Vol 359, pp 239-264 https://doi.org/10.1017/S002211209700846X
  8. Patel, V.C., Rodi, W. and Scheuerer, G. (1985). 'Turbulence Models for Near-wall and Low Reynolds Number Flows : A Review', AIAA J., Vol 23, No 9, pp 1308-1319 https://doi.org/10.2514/3.9086
  9. Williams, A.N. and Abul-Azm, A.G. (1997). 'Dual Pontoon Floating Breakwater', Ocean Eng., Vol 24, pp 465-478 https://doi.org/10.1016/S0029-8018(96)00024-8
  10. Williams, A.N., Lee, H.S., and Huang, Z. (2000). 'Floating Pontoon Breakwater', Ocean Eng., Vol 27, pp 221-240 https://doi.org/10.1016/S0029-8018(98)00056-0