A semi-empirical approach for determining the number density and void fraction of acoustic cavitation bubbles in sono-reactors

A new semi-empirical technic has been established relying on the linkage between the chemistry in the bulk liquid and that taking place in the acoustic cavitation bubble. The open-source COPASI software has been used for the optimization of number density according to the total yield of a single bubble and the fitting of the experimental yield of hydrogen peroxide in the sonicated solution. It was observed that the number density is increased with the rise of ultrasound frequency from 200 to 1140 kHz, independently of the saturating gas nature (O2, Ar or air).
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A semi-empirical approach for determining the number density and void fraction of acoustic cavitation bubbles in sono-reactorsReceived: 18 November 2022 Revised: 15 February 2023 Accepted: 5 May 2023DOI: 10.1002/vjch.202200207RESEARCH ARTICLEA semi-empirical approach for determining the number densityand void fraction of acoustic cavitation bubbles insono-reactorsAissa Dehane Slimane MerouaniLaboratory of Environmental ProcessEngineering, Department of Chemical AbstractEngineering, Faculty of Process Engineering, A new semi-empirical technic has been established relying on the linkageUniversity Constantine 3 Salah Boubnider,Constantine, Algeria between the chemistry in the bulk liquid and that taking place in the acoustic cavitation bubble. The open-source COPASI software has been used for the opti-Correspondence mization of number density according to the total yield of a single bubble and theAissa Dehane, Laboratory of Environmental fitting of the experimental yield of hydrogen peroxide in the sonicated solution. ItProcess Engineering, Department of Chemical was observed that the number density is increased with the rise of ultrasound fre-Engineering, Faculty of Process Engineering,University Constantine 3 Salah Boubnider, P.O. quency from 200 to 1140 kHz, independently of the saturating gas nature (O2 , ArBox 72, 25000 Constantine, Algeria. or air). Within this range of wave frequencies, i.e. from 200 to 1140 kHz, the num-Email: aissaleon15@gmail.com; ber of active bubbles goes up from 9.35 × 107 to 3.65 × 1015 L−1 s−1 . On the otheraissaleon@yahoo.com side, it has been demonstrated that the number density obtained under air atmo-Funding information sphere is greater than that resulting either under argon or oxygen-saturating gas.Ministry of Higher Education and Scientific Interestingly, with respect to the saturating gas nature (O2 , Ar, air) and the range ofResearch of Algeria, Grant/Award Number: ultrasound frequency (200–1140 kHz), it was observed that the increase of num-A16N01UN250320220002; General Directorateof Scientific Research and Technological ber density was not necessarily accompanied by a proportional increase of voidDevelopment (GD-SRTD) fraction (total volume of bubbles). KEYWORDS COPASI software, number density, saturating gas, semi-empirical method, ultrasound frequency, void fraction1 INTRODUCTION In = 1 W/cm2 ) determined the bubble size distribution in an actual sonochemical reactor using the FraunhoferWithin the sono-irradiated field, the collapse of micron- laser diffraction (LD) method with temporal separation ofsized bubbles produces enormous pressures (several hun- the acoustic wave disturbance (pulsed sonication). More-dred atmospheres) and temperatures (thousands of degree over, they also reported the effects of surfactant in theKelvin). A range of industrial and scientific applications ben- equilibrium state and the effect of pulse length. A com-efit from the advantageous physical and chemical effects paratively smaller bubble size range was achieved, whichproduced by these critical conditions.1–10 However, the is found to be closer to the resonance size range of thecontrol and optimization of cavitation systems are chal- cavitation bubbles, at short pulse length, lower pulse num-lenging and have been the subject of various research ber, and in the presence of low concentrations of SDS.because of the chaotic nature of acoustic cavitation bub- Additionally, an optimal number density was found in rela-bles. In general, the analysis of size distribution, bubbles tion to the turn-on period, while the number of bubblescoalescence, bubble deformation, void fraction (total vol- increased as the surfactant concentration rose. But sinceume of bubbles), secondary Bjerknes force and other laser diffraction and the phase Doppler method are basedphenomena were the subjects of numerous theoretical on measuring scattered laser light from bubbles, theseand experimental works. Iida et al.11 (freq = 443 kHz, methods are highly sensitive to a variety of phenomena© 2024 Vietnam Academy of Science and Technology and Wiley-VCH GmbH.Vietnam J. Chem. 2024;62:141–150. wileyonlinelibrary.com/journal/vjch 141 25728288, 2024, 2, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/vjch.202200207 by Readcube (Labtiva Inc.), Wiley Online Library on [01/05/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley On ...