Pramana | |
Oscillatory dynamics of a charged microbubble under ultrasound | |
J Balakrishnan32  Thotreithem Hongray3  B Ashok1  | |
[1] Centre for Complex Systems and Soft Matter Physics, International Institute of Information Technology-Bangalore, 26/C Electronics City, Hosur Road, Bangalore 560 100, India$$;School of Natural Sciences and Engineering, National Institute of Advanced Studies, Indian Institute of Science Campus, Bangalore 560 012, India$$;School of Physics, University of Hyderabad, Central University P.O., Gachi Bowli, Hyderabad 500 046, India$$ | |
关键词: Charged bubble dynamics; acoustic cavitation; nonlinear oscillations; bifurcation diagrams; largest Lyapunov exponents.; | |
DOI : | |
学科分类:物理(综合) | |
来源: Indian Academy of Sciences | |
【 摘 要 】
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 ð‘„min above which the bubble’s radial oscillations can occur above a certain velocity ð‘1 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 $ðœ”_{H}$ above which uncharged bubbles necessarily have to oscillate at velocities below $c_{1}$. We further find that this critical frequency crucially depends upon the amplitude $P_{s}$ of the driving acoustic pressure wave. The temperature of the gas within the bubble is calculated. A critical value ð‘ƒtr of $P_{s}$ equal to the upper transient threshold pressure demarcates two distinct regions of 𜔠dependence of the maximal radial bubble velocity ð‘£max and maximal internal temperature ð‘‡max. Above this pressure, ð‘‡max and ð‘£max decrease with increasing ðœ”, while below ð‘ƒtr, they increase with ðœ”. The dynamical effects of the charge, the driving pressure and frequency of ultrasound on the bubble are discussed.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
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RO201912040499091ZK.pdf | 7063KB | download |