Analysis of submerging characteristics and stability of the model submersible fish cage operated by buoyancy control

Abstract

This study aims to analyze the performance of a submersible fish cage which was designed for developing an economical cage system can be applied in korean aquaculture environment easily . To analyze the performance of the designed cage a model test was carried out . In the test , inclination changes of the upper frame and mooring tensions of model cage were measured during the submerging and surfacing motion in still water and wave condition (period : 2 s, wave height : 0.1, 0.2, 0.3 m). As a result , in the still water condition the model cage kept horizontal balance and inclination degree of the upper frame was about 1。 . In the wave condition , the model cage showed bilateral symmetric up-and-down motion but the average inclination degree of the upper frame was about 0 。 . When the model cage reached at a depth of 1m, the upand-down motion of the cage was decreased by 12% compared with that of at the surface (period 2s, height 0.3 m). In the same wave condition , the maximum and average line tension under the bottom position were about 8% and 11% respectively compared with that of at surface .