Numerical Characterization of Acoustic Cavitation Bubbles with Respect to the Bubble Size Distribution at Equilibrium

Abstract

In addition to bubble number density, bubble size distribution is an important population parameter governing the activity of acoustic cavitation bubbles. In the present paper, an iterative numerical method for equilibrium size distribution is proposed and combined to a model for bubble counting, in order to approach the number density within a population of acoustic cavitation bubbles of inhomogeneous sizing, hence the sonochemical activity of the inhomogeneous population based on discretization into homogenous groups. The composition of the inhomogeneous population is analyzed based on cavitation dynamics and shape stability at 300 kHz and 0.761 W/cm2 within the ambient radii interval ranging from 1 to 5 µm. Unstable oscillation is observed starting from a radius of 2.5 µm. Results are presented in terms of number probability, number density, and volume probability within the population of acoustic cavitation bubbles. The most probable group having an equilibrium radius of 3 µm demonstrated a probability in terms of number density of 27%. In terms of contribution to the void, the sub-population of 4 µm plays a major role with a fraction of 24%. Comparisons are also performed with the homogenous population case both in terms of number density of bubbles and sonochemical production of HO●, HO2●, and H● under an oxygen atmosphere.

Boosting Photocatalytic Hydrogen Evolution Reaction by the Improved Mass Flow and Energy Flow Process Based on Ultrasound Waves

“…Ultrasonic frequency is an important physical parameter of the sono-chemical reaction that can significantly affect the size of cavitation bubbles. It is found that as the frequency increases, the cavitation temperature and pressure can be increased; when the ultrasonic frequency increases to a certain level, the size and lifetime of the cavitation bubbles decrease, − which weakens the cavitation intensity and thus reduces the efficiency of the photocatalytic reaction.…”

Effect of Organic Ions on The Formation and Collapse of Nanometric Bubbles in Ionic Liquid/Water Solutions: A Molecular Dynamics Study

“…Furthermore, at variance from the setup commonly used in sonoluminescence experiments, our samples do not include dissolved gas species. In this simpler context, the more complicated models give the same answer as the original Rayleigh–Plesset equation, then, we will only consider the RP model in our discussion. − …”

“…In this simpler context, the more complicated models give the same answer as the original Rayleigh–Plesset equation, then, we will only consider the RP model in our discussion. 52 − 57 …”

Sono-electrolysis performance based on indirect continuous sonication and membraneless alkaline electrolysis: Experiment, modelling and analysis

“…For instance, the sonochemical process of generation of free radicals [14] , [15] , degradation of organic contaminants [16] , [17] , or even production of hydrogen [18] , [19] , [20] has been elucidated through chemical mechanisms associated to the thermodynamics of the oscillation of the single acoustic cavitation bubble. The population dimension has been also integrated in the modelling of sonochemistry [21] , [22] , through the number density of bubbles [23] , [24] and their size distribution [25] . On the other hand, the physical effects associated with the oscillation of the single acoustic cavitation bubble have been studied via mathematical modelling and simulation in a number of scientific papers dealing with microjets [26] , shockwaves [27] , acoustic streaming [28] and microstreaming [29] .…”