Analysis of hydrodynamic behaviors of multiple net cages in combined wave–current flow

Numerical simulation is performed to analyze the hydrodynamic response of a net cage and submerged mooring grid system exposed to waves and current. A series of experiments are conducted to validate the numerical model of net cage and grid mooring system. The numerical results of this model correspond with those obtained from experimental observations. Then, the numerical simulation of a multi-cage and mooring system under the action of waves combined with current is conducted. The influence of waves and current directions and the length of grid lines on the cage responses are discussed. The twin mooring system and the orthogonal mooring system are compared. Results show that for the orthogonal mooring system, the maximum tension force on the anchor line of the four-cage system is less than four times of that of the single-cage system, when both waves and current travel along the x-axis. The minimum net cage volume holding coefficient of the single-cage system is smaller than that of the four-cage system. The amplitude of the mooring line tension force for the twin mooring system is larger than the orthogonal mooring system.

[1]  Fuxiang Hu,et al.  A static analysis of the tension and configuration of submerged plane nets , 2002 .

[2]  James D. Irish,et al.  Development of large fish farm numerical modeling techniques with in situ mooring tension comparisons , 2007 .

[3]  Holger Korte,et al.  Application of NaLA, a fishing net configuration and loading analysis system, to bottom gill nets , 2009, Fisheries Science.

[4]  Are Johan Berstad,et al.  Design Rules for Marine Fish Farms in Norway: Calculation of the Structural Response of Such Flexible Structures to Verify Structural Integrity , 2004 .

[5]  A. Berstad,et al.  Response from current and regular/irregular waves on a typical polyethylene fish farm , 2006 .

[6]  Mario J. Casarella,et al.  HYDRODYNAMIC RESISTANCE OF TOWED CABLES , 1971 .

[7]  Bin Teng,et al.  Hydrodynamic behavior of a straight floating pipe under wave conditions , 2007 .

[8]  Yoon-Rak Choi,et al.  A Study On the Hydrodynamic Behavior of Fisheries Cages In Waves , 2002 .

[9]  Hsien Hua Lee,et al.  The dragged surge motion of tension-leg type fish cage system subjected to multi-interactions among wave and structures , 1999 .

[10]  Jin-Yuan Liu,et al.  Dynamical analysis of net cage structures for marine aquaculture: Numerical simulation and model testing , 2006 .

[11]  Odd M. Faltinsen,et al.  Modelling of current loads on aquaculture net cages , 2012 .

[12]  T. Hedges,et al.  The equivalent uniform current in wave-current computations , 1992 .

[13]  Bin Teng,et al.  Numerical simulation of the effects of structure size ratio and mesh type on three-dimensional deformation of the fishing-net gravity cage in current , 2007 .

[14]  Barbaros Celikkol,et al.  Modeling of dynamic behavior of a single-point moored submersible fish cage under currents , 2010 .

[15]  Basil W. Wilson.  Elastic Characteristics of Mooring , 1967 .

[16]  Yun-Peng Zhao,et al.  Numerical investigation of the hydrodynamic behaviors of multiple net cages in waves , 2012 .

[17]  Chai-Cheng Huang,et al.  Numerical Modeling for an In Situ Single-Point-Mooring Cage System , 2010, IEEE Journal of Oceanic Engineering.

[18]  Wei-Ming Chen,et al.  Dynamics of dual pontoon floating structure for cage aquaculture in a two-dimensional numerical wave tank , 2011 .

[19]  David W. Fredriksson,et al.  The design and analysis of a four-cage grid mooring for open ocean aquaculture , 2004 .

[20]  C. Brebbia,et al.  Dynamic analysis of offshore structures , 1979 .

[21]  J. DeCew,et al.  A case study of a modified gravity type cage and mooring system using numerical and physical models , 2005, IEEE Journal of Oceanic Engineering.

[22]  Odd Sture Hopperstad,et al.  Structural analysis of aquaculture net cages in current , 2010 .

[23]  N. Bose,et al.  Aquaculture Net Drag Force and Added Mass , 2009 .

[24]  Hao Wu,et al.  An experimental and numerical study of hydrodynamic characteristics of submerged flexible plane nets in waves , 2008 .

[25]  Are Johan Berstad,et al.  Enhancement of Design Criteria for Fish Farm Facilities Including Operations , 2005 .

[26]  David W. Fredriksson,et al.  Development of a porous media model with application to flow through and around a net panel , 2010 .

[27]  James D. Irish,et al.  Fish cage and mooring system dynamics using physical and numerical models with field measurements , 2003 .

[28]  H. Korte,et al.  Application of NaLA, a fishing net configuration and loading analysis system, to drift gill nets , 2005 .

[29]  Zhi Zong,et al.  Elastic responses of a flotation ring in water waves , 2010 .

[30]  Chai-Cheng Huang,et al.  Mooring line fatigue: a risk analysis for an SPM cage system. , 2010 .

[31]  Yu-cheng Li.  Hydrodynamic Behavior of Net Cages in the Open Sea , 2009 .