Liquid compressibility effect on the acoustic generation of free radicals

Abstract

Even through the liquid compressibility effect on acoustic cavitation has already been investigated by several authors, their results, however, are still limited to the radial dynamics and the thermodynamic behavior of the gas inside the bubble. In this computational study, the effect of liquid compressibility was investigated on both the bubble dynamics and the resulted chemical reactions inside the bubble at the collapse. Two cavitation models, based on Rayleigh-Plesset (RP) equation for incompressible medium and that of Keller-Miksis (KM) for compressible one, were adopted. A reaction scheme consisting on 25 reversible reactions was used for simulating the chemistry occurring inside the bubble at the strong collapse. The inclusion of liquid compressibility induced lower bubble temperature (T_max), pressure (p_max) and chemical yield of the oxidants inside the bubble at the strong collapse. Furthermore, frequency and acoustic strongly affected the effect of liquid compressibility.

KEYWORDS:

• Acoustic cavitation
• compressibility
• bubble dynamics
• chemical kinetics
• frequency
• acoustic intensity

Acknowledgments

This study was supported by The Ministry of Higher Education and Scientific Research of Algeria (project No. A16N01UN250320180001) and The General Directorate of Scientific Research and Technological Development (GD-SRTD). The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group No. RG-1441-501.

Notes

1 Results for the bubble collapse duration are available in Refs. Merouani et al. (2014b, Merouani et al. 2016).

Additional information

Notes on contributors

Slimane Merouani

Dr. Slimane Merouani is an Associate Professor of process engineering at Constantine 3 Salah Boubnider University (Algeria). His research interests focus on Environmental Chemical Engineering and innovative technologies for water and wastewater treatment, especially, sonochemistry and advanced oxidation processes. He has published more than 50 papers and he has an h-index of 18 (scopus).

Oualid Hamdaoui

Oualid Hamdaoui is a full Professor of Chemical Engineering and founding member of the Algerian Academy of Sciences and Technologies. He received his B.Sc. and M.Sc. both in Chemical Engineering from University of Annaba (Algeria). He obtained his Ph.D. in Environmental Chemical Engineering from University of Savoie (France) and Sc.D. in Chemical Engineering from University of Annaba in 2004. He completed his Habilitation (Accreditation to Supervise Research) in Process Engineering from University of Annaba in 2005. His main research interests are focused on advanced oxidation processes, sonochemistry, process intensification by ultrasound and separation processes.

Nassim Kerabchi

Nassim Kerabchi is a PhD student at the Laboratory of Environmental Engineering at the Department of Process engineering of the University of Annaba.