Oscillatory dynamics of a charged microbubble under ultrasound

Hongray, Thotreithem and Ashok, B and Balakrishnan, Janaki (2015) Oscillatory dynamics of a charged microbubble under ultrasound. Pramana: Journal of Physics, 84 (4). pp. 517-541.

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Abstract: Nonlinear oscillations of a bubble carrying a constant charge and suspended in a fluid, undergoing periodic forcing due to incident ultrasound are studied. The system exhibits period-doubling route to chaos and the presence of charge has the effect of advancing these bifurcations. The minimum magnitude of the charge Qmin above which the bubble’s radial oscillations can occur above a certain velocity c1 is found to be related by a simple power law to the driving frequency ! of the acoustic wave. We find the existence of a critical frequency !H above which uncharged bubbles necessarily have to oscillate at velocities below c1. We further find that this critical frequency crucially depends upon the amplitude Ps of the driving acoustic pressure wave. The temperature of the gas within the bubble is calculated. A critical value Ptr of Ps equalling the upper transient threshold pressure demarcates two distinct regions of ! dependence of the maximal radial bubble velocity vmax and maximal internal temperature Tmax. Above this pressure, Tmax and vmax decrease with increasing ! while below Ptr, they increase with !. The dynamical effects of the charge and of the driving pressure and frequency of ultrasound on the bubble are discussed.
Item Type: Article
Additional Information: Copyright belongs to Publisher
Keywords: Charged bubble dynamics; acoustic cavitation; nonlinear oscillations; bifurcation diagrams; largest Lyapunov exponents
Subjects: School of Natural and Engineering Sciences > Mathematical Modeling
Programmes > Complex Systems Programme
Divisions: Schools > Natural Sciences and Engineering
Date Deposited: 10 Sep 2015 06:17
Last Modified: 10 Sep 2015 06:17
Official URL: http://www.ias.ac.in/pramana/v84/p517/fulltext.pdf
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    Funders: UNSPECIFIED
    Projects: UNSPECIFIED
    URI: http://eprints.nias.res.in/id/eprint/669

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