Physical Study on Motion and Deformation of an Aquaculture Cage Using a 2D and 3D Nonintrusive Imaging Method

The purpose of this study was to solve a fluid-structure coupling problem with the aim of optimizing aquaculture cage design and construction using laboratory observation. In the experiments, the display of a non-intrusive stereo imaging measurement of the three-dimensional net geometry was established by tracing the positions of the LED markers on the cage net. A 1/30-scale model of a net cage was used composing of top and bottom hoops (or rings), nets, four buoys and four anchor blocks moored to the tank bottom. Trinocular stereo imaging, which used three synchronized video cameras to follow the three-dimensional displacements of 37 Light Emitting Diodes (LEDs) attached to the net, was employed to monitor the deformation and motion of the fish net. The motion of the collar and bottom hoop under different current velocities was also observed and is discussed in this paper. This measurement method offers more convenience and detail about deformation and motion investigation of a flexible net structure.