Numerical investigation of the effect of dual frequency sonication on stable bubble dynamics

Abstract

A computational study aiming to simulate an oxygen single acoustic bubble oscillation under a dual-frequency sonication was presented in this paper. The non-linear response of the bubble to the superposition of two fields of ultrasonic waves was investigated through dynamics parameters, collapse ratios and average velocities. The main goal of this analyze is to link the properties of the wave resulting from the dual-frequency excitation to the dynamics behavior of the bubble. The obtained results prove that, in contrast with the mono-frequency, coupling a wave to lower frequencies enhances the collapse duration and raises the compression ratio in the case of 35 kHz, while associating any of the studied waves to a higher frequency elevates the number of bubble oscillations during a time interval as compared to mono-frequency. The total sonochemical production has been investigated in accordance with the dynamics results, as well as the proportions of the three predominant free radicals, that show a dependency on the value of the basic frequency.

Effects of flat sweep frequency and pulsed ultrasound on the activity, conformation and microstructure of mushroom polyphenol oxidase

“…Kerboua et al . [30] investigated the effect of dual-frequency ultrasound on bubbles and found that coupling the wave to a lower frequency enhanced the collapse duration compared to a single frequency. Avvaru et al [31] found a synergistic effect of dual-frequency operation in increasing sonochemical yields, enabling higher sonochemical yields at an equivalent level of total power dissipation.…”

The importance of chemical mechanisms in sonochemical modelling

“…From the mid-2000s, Hamdaoui, Merouani, Kerboua and their group have also published studies regularly about chemically active single bubble [59] , [60] , [61] . Only to name a few from their extensive work: they examined the sensitivity of free radicals on different gas content [62] , studied the effect of multiple driving frequencies [63] , or even made energy-efficiency considerations [64] .…”

GPU accelerated numerical investigation of the spherical stability of an acoustic cavitation bubble excited by dual-frequency

“…In the last decades, many theories emerged to explain the influence of multiple excitation frequencies, for example, more active zones are generated in the sonochemical reactor [55] , [56] due to the better pattern of the acoustic waves. Others reported the increase of nuclei generated in the bubble cluster [57] , [54] , increased mass transfer via micromixing [58] , the increase of collapse-strength [51] , [59] , [60] , [34] or the lowering of cavitational threshold [61] , [62] . The combination and simultaneous resonance properties of dual-frequency driving can also explain the increased collapse strength [63] .…”