Abstract:  In order to provide theoretical basis for type section and design of aquaculture ponds, computational fluid dynamics (CFD) simulation analysis of velocity flow field is conducted for two classical dual-channel circular aquaculture ponds – Cornell and Waterline under the conditions of the same body size, water flooding velocity and water yielding ratio at the bottom of the ponds. Fluent module of Ansys 15.0 software is applied to simulation, RNG k-ε turbulence model is applied to numerical simulation of velocity flow fields inside the two ponds, and characteristics of the flow fields are analyzed and compared. The results show that the water velocity in the two ponds increases sharply with reduction of the radial distance in a short distance towards the center, reaches the maximum at certain radial distance, and then decreases with reduction of the radial distance before reaching the minimum in the central axis of the ponds or nearby; longitudinally, the water velocity decreases with increase of the height at the same horizontal distance to the center; when water yielding ratio at the bottom of the ponds is below 10%, both the bottom self-cleaning capacity and the overall flow field uniformity of Cornell are worse than Waterline. The results also verify that the empirical design value of water yielding ratio at the bottom of the two ponds is above 10% theoretically.

Key words: Circular aquaculture pond, hydrodynamic characteristics, numerical simulation, computational fluid dynamics, RNG k-ε
 

摘要： 为给养殖池的池型选择与设计提供理论依据，在相同的池体尺寸、进水速度和池底出水比例条件下，针对Cornell和Waterline两种经典双通道圆形养殖池，对其速度流场进行了计算流体动力学（CFD）仿真分析。仿真应用Ansys 15.0软件中的Fluent模块，采用RNG k-ε湍流模型对两种池型的内部速度流场进行了数值模拟，分析其流场特性并进行对比。对比结果显示，两种池型的水流速度向池中心方向在很短距离内随着径向距离的减少而急速增大，当达到某一径向距离时，速度达到最大值，然后速度随着径向距离的减小而减小，在池子中心轴线或附近处速度降到最小；在纵向上，与池心相同水平距离处的水体流转速度则随着高度增加而减小；在池底出水分流比小于10%时，Cornell池池底自清洁能力、池子整体流场均匀性均比Waterline池差。仿真结果也从理论上验证了两种池型底流比例的经验设计值在10%以上的原因。

关键词: 圆形养殖池, 水动力特性, 数值模拟, 计算流体动力学, RNG k-&epsilon