Research on hydrodynamic characteristics of circular aquaculture tank based on PIV technology

Abstract

The diameter-depth ratio of the water inlet pipe in the aquaculture tank (the ratio of the diameter of the aquaculture tank to the water depth, D/H) and the setting angle of the water inlet pipe (the acute angle formed by the water outlet direction and the tangent to the tank wall, α) are important factors that affect the hydrodynamic characteristics of the tank and directly affect the circulation. The comprehensive performance of the aquaculture system, in order to study the influence of the diameter-depth ratio of the aquaculture tank and the setting angle of the inlet pipe on the flow field of the aquaculture tank, this paper uses the particle image velocimetry (PIV) to measure the effect of different diameter-depth ratios and the setting angle of the inlet pipe on the circular shape. Hydrodynamic characteristics of circulating water aquaculture tanks. The test selects the single-pipe water intake mode commonly used in actual production for the circular aquaculture tank as the research object, and selects three groups of commonly used D/H conditions (3:1, 4:1, 5:1), Set up 8 groups of inlet pipe setting angles for each group of D/H conditions. In the experiment, the PIV technology was used to measure the flow field of the water layer 1 cm from the bottom of the tank under different working conditions, and the hydrodynamic characteristics of the culture tank were quantitatively analyzed through 2 aspects: the average flow velocity v avg and the velocity uniformity coefficient DU 50.The comprehensive test results show that the D/H and the setting angle of the inlet pipe obviously affect the flow field and hydrodynamic characteristics of the aquaculture tank. With the increase of the D/H, the v avg in the aquaculture tank gradually decreases, and the DU 50 gradually decreases. The changing trends of the hydrodynamic characteristics of the aquaculture tank with the setting angle of the inlet pipe under different D/H conditions are similar. When the water inlet pipe is set at an angle of 50°∼60°, the sewage collection and hydrodynamic characteristics in the aquaculture tank are optimal. The research results in this paper can provide a reference for the setting method of the inlet pipe of the circular aquaculture tank for industrial circulating water.