Insight into the impact of excluding mass transport, heat exchange and chemical reactions heat on the sonochemical bubble yield: Bubble size-dependency

Abstract

Highlights Effects reactions heat and mass and heat transfer on chemical bubble yield are studied. The effect the three energetic mechanisms depend on ambient bubble radii, frequency and acoustic amplitude. The ignorance of thermal conduction improves the bubble energy and the chemical yield. Excluding chemical reactions heat accelerate notably the chemical bubble yield. Excluding mass transport of water vapor lowers the chemical bubble yield.

An alternative technique for determining the number density of acoustic cavitation bubbles in sonochemical reactors

“…It is initially critical to demonstrate how to determine the single bubble conversion of CCl 4 using the model described in Section 2 . Even though we have done this in detail in our earlier works [61] , [82] for many simulation circumstances (frequency, acoustic intensity, and liquid temperature), it is best to describe briefly the topic here to provide the reader a quick grasp of the established approach. The evolution of the bubble dynamics, the bubble temperature and pressure, and the interior bubble chemistry are illustrated in Fig.…”

“…Furthermore, the higher number density obtained in our study under the experimental conditions of Pétrier and Francony compared to that of Hung and Hoffmann is probably promoted by the relatively higher CCl 4 concentration and liquid temperature used by Pétrier and Francony [62] (0.43 mM and 20 °C) compared to those of Hung and Hoffmann [48] (0.2 mM and 13 °C). In fact, the increase of CCl 4 concentration and the liquid temperature is expected to induce the activation of more bubbles (increases the number density) even when the maximal bubble temperature is reduced [82] .…”

“…This approach has been adopted from the work of Toegel et al [75] ( i.e. which is one of the pioneers in sonoluminescence and sonochemistry fields) and it is largely used in several theoretical studies giving interesting results in sonochemistry [60] , [65] , [67] , [75] , [79] , [82] , [83] . This assumption is supported by the short lifetime of the bubble and the very short collapsing time especially at higher ultrasound frequencies, which is the case of our study (200–1078 kHz).…”

Numerical modelling of acoustic cavitation threshold in water with non-condensable bubble nuclei

“…Recently, Peng et al [25] conducted a similar analysis for acoustic cavitation of vapor and argon mixture bubbles with initial radii of 1.5 and 4.5 and obtained the optimum liquid temperature that maximizes the bubble collapse intensity, depending on the acoustic frequency and amplitude. Dehane et al [26] , [27] , [28] , [29] also performed a numerical analysis for acoustic cavitation of ambient (or initial) bubbles with radii of 0.5–14 , including the effects of heat and mass transfer and chemical reaction. They investigated the bubble collapse temperature and pressure in various acoustic amplitude and frequency conditions.…”

“…Although the previous works [23] , [24] , [25] , [26] , [27] , [28] , [29] have advanced the analysis of acoustic cavitation including the phase-change effect, their analysis was limited in that the heat and mass transfer rates were calculated from the boundary layer approximations with adjusting factors instead of solving the conservation equations. Their applications were mainly acoustic cavitation of microbubbles, which are relatively larger than the nanobubble nuclei [13] expected in real tap or degassed water.…”