Microbubble generation driven by the oscillation in a self‐excited fluidic oscillator

Abstract

Abstract The oscillation‐driven microbubble generation in a self‐excited fluidic oscillator is explored in this work. By investigating the behaviors of bubbles, it is noted that for relatively low liquid flow rate, bubbles move upward directly and breakup does not occur inside the chamber region. Interestingly, the existence of bubbles could destroy the structure of flow field and even affect the oscillation. Nevertheless, for relatively high liquid flow rate, the bubbles would not be able to change the flow field structure of liquid phase effectually. Meanwhile, binary, shear‐off‐induced and a kind of dynamic erosive breakup of the bubbles could occur for the effects of oscillations of liquid main jet. Abundant microbubbles could be produced mainly by the dynamic erosive breakup. The oscillation is only induced by the Coanda effect without any moving parts. Nevertheless, it is able to supply a robust oscillating turbulent field to enhance the breakup of bubbles dramatically.