不同池型结构循环水养殖池水动力特性研究

Effect of Structures on Hydrodynamic Characteristics of Recirculating Aquaculture Pond

为构建兼具良好水动力性能和高空间利用率的循环水养殖池,对比研究了正方形、六边形、八边形、圆形、方形切角、方形圆弧角6种池型养殖池的水动力特性及综合性能。在试验数据验证计算方法有效的基础上,研究了池型结构对流动均匀性、流速分布、涡量分布、水体混合均匀性及自净化效能的影响作用,并从适渔性、循环水的利用率、空间利用率等方面分析了养殖池的综合效能。研究表明:随着养殖池的切角距离和圆角半径增大,底流速度增大,水流均匀性、涡流强度和二次流强度增强,有利于提高循环水养殖池的水体混合与自净化效能,但养殖池的空间利用率降低;随着切角距离和圆角半径减小,水体平均速度降低,要维持适宜的速度范围就要增大射流速度,产生更多废水,降低循环水利用效率;正六边形、0.4396<k_(1)<0.5858的方形切角养殖池、0.6667<k_(2)<0.8333的方形圆角养殖池具有更高的综合性能。

In order to build an industrial recirculating aquaculture pond with good hydrodynamic performance and high space utilization,the hydrodynamic characteristics and comprehensive performance of aquaculture ponds with six types of structures were compared and studied,including square,hexagon,octagon,circle,square with chamfer and square with fillet.On the basis of verifying the effectiveness of the numerical method,the influence of different structures on the velocity distribution,flow uniformity,vorticity distribution,water mixing uniformity and purification efficiency of the flow field were studied.The comprehensive performances of recirculating aquaculture ponds with different structures were evaluated from the aspects of fishing suitability,utilization rate of circulating water and space utilization rate.The results showed that with the increase of the chamfering distance and fillet radius,the water velocity distribution became more uniform,the underflow velocity was increased,and the flow uniformity,eddy current intensity and secondary flow intensity were increased gradually,which was conducive to improve the water mixing and self-purification efficiency but reduce the space utilization rate.With the decrease of the chamfering distance and fillet radius,the average velocity of the aquaculture water was gradually decreased,and the utilization efficiency of input energy of the jet was decreased.To maintain the appropriate speed range,it was necessary to increase the jet velocity,so as to produce more wastewater and reduce the utilization efficiency of the circulating water.Regular hexagon,square corner pond with k_(1) from 0.4396 to 0.5858 and square fillet pond with k_(2) from 0.6667 to 0.8333 had higher comprehensive performance.The research result could provide a theoretical basis and reference for the optimal design of recirculating aquaculture ponds,and had application value and scientific significance.