Numerical investigations of single bubble oscillations generated by a dual frequency excitation

9th International Symposium on Cavitation

Guédra, Matthieu^1,2 ; Inserra, Claude^1,2 ; Gilles, Bruno^1,2 ; Béra, Jean-Christophe^1,2

Inserm, U1032, LabTau, Lyon

F-69003, France^1

Université Lyon 1, Lyon

F-69003, France^2

关键词: Dual-frequency excitation;    High frequency components;    Low-frequency components;    Numerical investigations;    Specific frequencies;    Strong enhancement;    Temporal evolution;    Time-frequency representations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012019/pdf
DOI  :  10.1088/1742-6596/656/1/012019

来源: IOP

【 摘 要 】

The oscillations of a single bubble excited with a dual frequency acoustic field are numerically investigated. Computations are made for an air bubble in water exposed to an acoustic field with a linearly varying amplitude. The bubble response to an excitation containing two frequencies f1= 500kHz and f2= 400kHz at the same amplitude is compared to the monofrequency case where only f1is present. Time-frequency representations show a sharp transition in the bifrequency case, for which the low frequency component f2becomes resonant while the high frequency component f1is strongly attenuated. The temporal evolution of the power spectra reveals that the resonance of the low frequency component is correlated with the time varying mean radius of the bubble. It is also observed that the total power of the bubble response in the bifrequency case can reach almost twice the power obtained in the monofrequency case, which indicates a strong enhancement of the cavitating behavior of the bubble for this specific frequency combination.