自减流低形变网箱模型试验

通过在圆柱形网箱箱体深度的1/2处设置一个中环,将原来的圆形重力式网箱改造成新型自减流低形变网箱(改造后的新型实物网箱周长50 m、中环周长75 m、深8 m)。通过在东海水产研究所内主尺度为90m×6 m×3 m的试验水池对新型自减流低形变模型网箱进行模型试验,研究其箱体内容积和流速的变化。模型试验结果表明,新型网箱的容积保持率明显优于原型网箱,在流速1kn时容积保持率仍能达到90.4%。不同流速下,新型网箱的减流效果比原型网箱提高5.8%~13.9%,内部流速比箱体外界流速减小25.0%~31.2%。该新型网箱可有效降低箱体内的海水流速、提高箱体的容积保持率,为养殖鱼类提供更为良好的生存、生长环境。

Model experiment of low deformation and auto decrement current cage

A middle ring was set up in the middle of the cage,and formed the modified auto decrement current velocity cage(circumference 50 m,depth 8 m and middle ring circumference 75 m).As a cage model,experiments were made on the modified auto decrement current velocity cage in a flume tank of 90 m×6 m×3 m.Results showed that the volumetric maintenance rate of auto decrement current velocity cage was higher than that of the original cage;the new volumetric maintenance rate was up to 90.4% at 1 kn current velocity;the reducing current velocity effect of new cage increased by 5.8%-13.9% compared with that of the original;the inner current velocity of reducing current velocity cage decreased by 25.0%-31.2% compared with the external current velocity.The auto decrement current velocity cage effectively reduced velocity of inner cage and increased volumetric maintenance rate,which could supply better environment for cultured fishes.