Venturi Aeration Systems Design and Performance Evaluation in High Density Aquaculture

The efficiency of Venturi-based aeration systems depends heavily on throat length and the number of air holes (NH), which influence key parameters such as oxygen transfer efficiency (KLa20), standard aeration efficiency (SAE), and bubble dynamics. This study examined the performance of Venturi devices with throat lengths of 20, 40, 60, 80, and 100 mm and NH configurations ranging from 5 to 20 under controlled aquaculture conditions. The results demonstrated that a throat length of 100 mm with NH=20 achieved the highest SAE of 1.28 kg O2/kWh and produced the smallest bubble size of 0.03 mm. Bubble size decreased consistently with increasing NH, while longer throat lengths promoted uniform bubble distribution, enhancing gas-liquid mass transfer efficiency. A 3D analysis revealed that oxygen transfer efficiency plateaued beyond NH=15 due to turbulence saturation, highlighting the need for balanced design parameters. These findings provide practical design recommendations for optimizing Venturi aeration systems, particularly for high-density aquaculture, where efficient oxygenation and energy savings are critical. Future studies should investigate the effects of environmental variables and assess long-term system stability under real-world operational conditions.