When a strong ultrasonic source is introduced into a liquid, small bubbles form that cyclically grow and collapse in response to the applied acoustic pressure. These cavitating bubbles focus acoustic energy generating extremely high temperatures and pressures as the bubbles collapse. Under these conditions, molecular disassociation occurs resulting in the production of highly reactive free radicals. This sonochemical phenomenon has been shown useful in numerous industrial processing applications. The effect of bubble dynamics on chemistry occurring inside a cavitation bubble has been extensively investigated, but chemistry effects on bubble dynamics has not as previous studies neglect this critical phenomena. Surprisingly, the time scales associated with chemical reactions and bubble collapse are of the same order and must be considered to accurately predict bubble chemistry and dynamics. This paper presents a study of the coupling between bubble dynamics and chemical kinetics using a numerical model that directly relates the two. This study shows that the chemical reactions occurring at bubble collapse have significant effect on bubble dynamics and collapse temperature due to the release of heat from species reactions. A cavitating bubble in an ultrasonic field switches from one equilibrium state to another after a strong oxidation event and the total moles of species within a bubble drops as a result of the overall combustion effect. The result of this study provides insight into the physics of sonochemistry and has implications in the unusually high light emission observed in sonoluminescence.
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