Investigation of diameter-to-depth ratio on the hydrodynamics in recirculating aquaculture tank

Abstract

To maximize the spatial utilization rate of the recirculating aquaculture system (RAS) and improve the growth conditions of aquaculture varieties, the present study used the numerical simulation method to investigate the distribution characteristics of the flow velocity inside the aquaculture tank. It is of great practical importance for the design and optimization of the aquaculture tank structures. The computational fluid dynamics (CFD) method and the RNG k-ε turbulent model were applied to analyze the effects of diameter-to-depth ratio (L/H) on the hydrodynamic characteristics inside the aquaculture tank, including the average flow velocity, resistance coefficient, flow velocity uniformity, energy utilization coefficient, vortex and Fraud correction coefficients. The accuracy of proposed method was verified by experimental results. The results show that as the diameter-to-depth ratio (L/H) of the rectangular arc angle aquaculture tank increases, the turbulence intensity in the flow field gradually weakens, the low-velocity area increases, and the average flow velocity decreases. When the diameter-to-depth ratio (L/H) is 3:1–5:1, uniformity coefficients, energy effective use coefficients, and Fraud correction coefficients have significantly been improved, and the flow pattern in the aquaculture tank is the best. Through the research of the present study, it can effectively improve the utlization rate of aquaculture tank space, and provide technical support for the realization of the welfare aquaculture of the recirculating aquaculture system.