Flow pattern in aquaculture circular tanks: Influence of flow rate, water depth, and water inlet & outlet features

Circular tank geometry is very common in aquaculture because it provides more stable flow patterns, a more homogeneous distribution of dissolved oxygen and metabolites and better self cleaning features. Many works were performed in the last years to determine optimal velocities for maintaining general fish health, but the distribution of velocities inside circular tanks is frequently very heterogeneous. This work is focused on the analysis of the influence of design parameters in the distribution of water velocities inside aquaculture circular tanks. A model is proposed to estimate the distribution of velocities by determining the angular momentum per unit mass next to the tank wall and around the central axis. The model depends on the water inflow and outflow rates, the water inlet velocity, the tank radius, the water depth, and three tank-specific parameters which must be determined experimentally to include the effect of the wall roughness, the characteristics of water inlet devices and the presence of singular elements in the tank bottom producing friction loses. (C) 2012 Elsevier B.V. All rights reserved.