Numerical simulation of air-water flow on swirl-type microbubble generator

• Main Authors: Mubarok, Iskandar Ali, Mawarni, Drajat Indah, Indarto, Deendarlianto
• Format: Conference Proceeding
• Language: English
• Subjects: Air bubbles; Flow characteristics; Flow velocity; Parameter identification; Probability density functions; Simulation; Size distribution; Visual observation; Water flow
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0229895

In this study, Computational Fluid Dynamic (CFD) simulations were conducted to determine the flow characteristic of air-water phases in the swirl-type microbubble generator and bubble size distribution on the inside of the tank. Based on the visual observations from the experiment, the air-water phase interaction on the inside and outside of the microbubble generator is different. Thus, the simulation is divided into two sections. The first one is to simulate the continuous-continuous interaction of air-water on the inside of microbubble generator, while the other part is to simulate the continuous-dispersed interaction of air bubbles in water on the inside of the tank. Flow characteristics such as swirl flow and negative pressure was identified on the first part of this study, while the bubble size distribution was determined from the second part of simulation. It is appeared that parameters such as water flow rate and swirl number affect the bubble size distribution produced by microbubble generator. The higher water flow rate will decrease the size of bubble where the peak probability density function (PDF) value is obtained. While higher swirl number result in slimmer and higher PDF. The experimental measurement data on the bubble size distribution was used to validate the numerical results.