Effect of Throat Size on Pressure and Void Fraction Fluctuation in Venturi Tube Microbubble Generator

Abstract

The Venturi type microbubble generator generates microbubble through the breakup of air bubbles that flowed together with the flowing liquid. The breakup occurred as pressure fluctuated inside the tube due to the change of geometry along the tube. As pressure changed, the void fraction varied too. However, this fluctuation was not discussed in regard to the change of throat size. Therefore, we aim to investigate the effect of throat size on the pressure and void fraction fluctuation. The investigation took place using 2 different throat size Venturi tube while other geometry was made constant. Measurement of pressure and void fraction was done referring to a similar setup by the previous study. The result showed that at the same inlet pressure, reduced throat size resulted in lower outlet pressure and increased pressure loss. The void fraction was not significantly different but, the result of generated microbubbles was more promising for the 4 mm Venturi tube.