Numerical Simulation Of Hydrodynamic Characteristics Of Horizontal Cylindrical Marine Aquaculture Cages Under The Action Of Waves And Currents

Cages are currently the primary facility for most of the world’s marine aquaculture.In recent years,with the continuous development of marine resources,the scale of cage aquaculture has expanded rapidly,and the research and development of new breeding cages suitable for different conditions has also attracted more and more attention.Because traditional cages are immersed in seawater for a long time,marine organisms are easily attached to the cage structure,which poses a threat to the safety of the cage structure.The new horizontal cylindrical cage with rotatable cage can rotate the cage through the action of wave flow to achieve a certain self-cleaning effect.Therefore,it is necessary to study the hydrodynamic response of the rotatable horizontal cylindrical cage.In this paper,based on the Ansys computing platform,a new finite element model for hydrodynamic calculation of cages is established.The hydrodynamic response of the structure under the action of waves and currents was numerically simulated,and the hydrodynamic response of the cages under different water depths and different length-diameter ratios of the cages was studied.The force transmitted to the side brackets.In this paper,based on the Ansys computing platform,a new finite element model for hydrodynamic calculation of cages is established.The hydrodynamic response of the structure under the action of waves and currents was numerically simulated,and the hydrodynamic response of the cages under different water depths and different length-diameter ratios of the cages was studied.The force transmitted to the side brackets.First,for different wave heights and periods.The strain,acceleration,support reaction force and displacement response results of the cage all increase with the increase of wave height.But the change with the cycle is less pronounced.The acceleration response of the structure first decreased and then increased with the decrease of the elevation,while the displacement response of the structure increased with the increase of the elevation.In the direction of the Yaxis,the acceleration and displacement responses of the structure gradually increase from the two sections of the cage structure to the middle of the cage.The strain response was the opposite,decreasing gradually from the two sections of the cage structure to the middle of the cage.Secondly,for the hydrodynamic response of the structure under different water depths,the acceleration response,support reaction force and bending moment response of each measuring point of the structure all increase with the increase of water depth.The displacement response peaks are mostly distributed at the design low water level and the design high water level.For the strain response,most of its peak value decreases with the increase of the water level.When the water level is extremely low,the strain of the structure is the largest;for the hydrodynamic response of the structure under different cage length-diameter ratios.The peak of the acceleration response at both ends of the cage first increases and then decreases with the increase of the length-diameter ratio of the cage.It decreases with the increase of the lengthdiameter ratio of the cage,and reaches the maximum when the length-diameter ratio of the cage is 30,that is,the length of the cage is 60 m.The displacement response,strain response,support reaction force and bending moment response of the structure all increase with the increase of the length-diameter ratio of the cage.Finally,when the cage is rotated,the hydrodynamic response of the structure is larger than that when the cage is fixed,and the force and bending moment transmitted to the side supports of the cage when the cage is rotated are also higher than when the cage is fixed.When the net is loosely arranged,the acceleration response on the main axis of the structure is smaller than that when the net is tensioned.However,the force and bending moment transmitted to the side supports of the structure are basically the same under the two working conditions;under different wave incident angles,the hydrodynamic response of the structure decreases with the increase of the wave incident angle.When the wave incident angle is At 0°,the various hydrodynamic responses of the structure are the largest,which is related to the slender structure of the cage,indicating that the 0° direction is the most unfavorable wave incident angle to the structure.