Design and Simulation of Double-Nozzle Venturi Bubble Generator for Aeration System

Abstract

Aquatic organisms rely heavily on oxygen for survival and maintaining adequate dissolved oxygen (DO) levels is crucial for the health and productivity of aquaculture systems. Aeration methods, such as venturi bubble generators, play a vital role in enhancing DO concentrations by facilitating oxygen transfer from the atmosphere to water. This study explores the performance of traditional venturi bubble generators and introduces a novel double-nozzle design for potential improvements in energy efficiency and oxygen transfer. Using computational fluid dynamics (CFD), we compared the performance of conventional half-inch and one- inch venturi bubble generators to a newly proposed double-nozzle design. Pressure profiles, velocity distributions, turbulence characteristics, bubble size distributions, and energy losses were evaluated to assess the effectiveness of each design. Results revealed significant differences in performance among the three venturi bubble generator designs. Compared to traditional designs, the double-nozzle configuration demonstrated superior characteristics, including smaller bubble sizes, more uniform bubble distribution, and higher turbulence levels. However, the double- nozzle venturi bubble generator also exhibited notable power losses due to pressure fluctuations.