【摘要】 为改善带有顶、底边舱且低径深比的养殖工船养殖舱内流场特性，以提高水产养殖动物福利与经济效益，提出一种结构优化参数折角比(a/B,a为角壁边长，B为养殖舱壁边长),以评估养殖舱内流场的改善效果。基于计算流体动力学(CFD)仿真技术，研究折角比参数a/B(0～0.4)和进水速度(0.8～1.2 m/s)对养殖舱内流场特性的影响。结果显示：不同进水速度下，养殖舱内流体特性的变化趋势一致；养殖舱水力停留时间一致的条件下，当折角比参数0.25≤a/B≤0.40时，养殖舱内流场均匀性较好，平均流速较原方形养殖舱提高35%,能量有效利用率提高70%;角壁附近低流速区域减少，养殖舱中间排水口区域有明显涡柱形成，有助于提高养殖舱系统的自清洁性能。研究表明，折角比参数a/B控制在0.25～0.40时，有助于提高养殖舱系统的能量有效利用率和养殖空间利用率。研究结果可为养殖工船养殖舱的结构设计和优化提供参考依据。更多还原

【Abstract】 In order to improve the hydrodynamic characteristics of aquaculture tanks with top and bottom compartments and low diameter-to-depth ratio,so as to improve the welfare of aquaculture animals and the economic benefits.In this study,a new structural optimization parameter was proposed,namely the parameter of the bend ratiosa/B(a/B,ais the corner wall side length,B is the culture liquid bulkhead side length),to evaluate the improvement effect of the flow field inside the aquaculture tank.Based on computational fluid dynamics (CFD)simulation technology,the effects of the parameter of the bend ratiosa/B(0-0.40) and water inlet velocity (0.8-1.2 m/s) on the hydrodynamic characteristics in the aquaculture tank were studied.Firstly,in order to verify the correctness of the numerical model and the accuracy of the simulation results,a physical test model of the square aquaculture tank was established,and a numerical model of equal proportions was constructed.Next,the numerical simulation results of the water flow velocity in the aquaculture tank were compared with the test results of the physical model.On this basis,a 40∶1 scale was carried out on the prototype of the Japan Bulk Carrier to construct a numerical model of the aquaculture ship.Next,the flow field under 9 bend ratiosa/Band 3 inlet velocity conditions of the aquaculture tank system were numerically simulated.Under the same inlet velocity,the hydraulic retention time of each tank was basically equal by adjusting the number of water inlets,so as to quantitatively analyze the influence of the bend ratiosa/Bon the hydrodynamic of the aquaculture tank.(1) The average flow velocity ■ in the tank increases with the increase of the bend ratios a/B,and the trend is the same under the three inlet velocities.When the bend ratiosa/B=0.25-0.40,the average flow velocity of each section in the aquaculture tank is 35%higher than that of the original square aquaculture tank,and the velocity of each section is large and evenly distributed,and there is no obvious low flow velocity area.(2) The uniform distribution coefficientγ_Ain the aquaculture tank decreases first and then increases with the increase of the bend ratiosa/B.When the the bend ratiosa/B=0-0.1 and 0.25-0.40,the uniform distribution coefficientγ_Ais increased by 7%compared witha/B=0.1-0.25.(3) The energy utilization coefficientη_ein the aquaculture tank increases with the increase of the the bend ratiosa/B.When the bend ratiosa/B=0.3-0.40,the energy effective utilization coefficientη_eis 70%higher than that of the original square aquaculture tank.(4) With the increase of the bend ratiosa/B,the vortex column in the center of the aquaculture tank gradually stabilizes,so that the water can move regularly in the tank,and a large vortex ring gradually appears.From the color shading of the velocity,it can be seen that the flow velocity is higher near the tank wall.In aquaculture tanks with smaller bend ratiosa/B,large-scale vortex structures break down into many smaller-scale structures,vortex filaments,and irregular vortex distributions.The aquaculture tanks with the bend ratiosa/Bin the range of 0.25-0.40 have the characteristics of high average flow velocity,uniform flow field distribution,and no low flow velocity area.They also have a good water environment,high energy effective utilization rate and efficient utilization of aquaculture space.The results of this study have certain guiding significance for optimizing the design of aquaculture tank systems on aquaculture vessels and improving production efficiency.In practical applications,the flow field environment inside the aquaculture tanks can be adjusted based on the bend ratiosa/Bto maintain good water quality,improve aquaculture efficiency,and reduce operational costs.更多还原