Studies of non-linear bubble oscillations in a simulated acoustic field

1990 ◽  
Vol 11 (6) ◽  
pp. 352-358 ◽  
Author(s):  
T G Leighton ◽  
M Wilkinson ◽  
A J Walton ◽  
J E Field
Keyword(s):  
Acoustic Field ◽  
Non Linear ◽  
Bubble Oscillations

Collective oscillations in bubble clouds

2011 ◽  
Vol 680 ◽  
pp. 114-149 ◽  
Author(s):  
ZORANA ZERAVCIC ◽  
DETLEF LOHSE ◽  
WIM VAN SAARLOOS
Keyword(s):  
Frequency Response ◽  
Acoustic Field ◽  
Low Frequency ◽  
Acoustic Energy ◽  
Viscous Damping ◽  
Edge States ◽  
Bubble Cloud ◽  
Collective Oscillations ◽  
The Individual ◽  
Bubble Oscillations

In this paper the collective oscillations of a bubble cloud in an acoustic field are theoretically analysed with concepts and techniques of condensed matter physics. More specifically, we will calculate the eigenmodes and their excitabilities, eigenfrequencies, densities of states, responses, absorption and participation ratios to better understand the collective dynamics of coupled bubbles and address the question of possible localization of acoustic energy in the bubble cloud. The radial oscillations of the individual bubbles in the acoustic field are described by coupled linearized Rayleigh–Plesset equations. We explore the effects of viscous damping, distance between bubbles, polydispersity, geometric disorder, size of the bubbles and size of the cloud. For large enough clusters, the collective response is often very different from that of a typical mode, as the frequency response of each mode is sufficiently wide that many modes are excited when the cloud is driven by ultrasound. The reason is the strong effect of viscosity on the collective mode response, which is surprising, as viscous damping effects are small for single-bubble oscillations in water. Localization of acoustic energy is only found in the case of substantial bubble size polydispersity or geometric disorder. The lack of localization for a weak disorder is traced back to the long-range 1/r interaction potential between the individual bubbles. The results of the present paper are connected to recent experimental observations of collective bubble oscillations in a two-dimensional bubble cloud, where pronounced edge states and a pronounced low-frequency response had been observed, both consistent with the present theoretical findings. Finally, an outlook to future possible experiments is given.

scholarly journals Non-linear Acoustic Characterization of Microbubbles and Nanobubbles

2021 ◽  
Author(s):  
Grace Fishbein ◽  
Michael Kolios
Keyword(s):  
High Frequency Ultrasound ◽  
Contrast Enhanced ◽  
Acoustic Characterization ◽  
Non Linear ◽  
Linear Behaviour ◽  
Linear Contrast ◽  
Bubble Oscillations ◽  
Focused Transducers ◽  
Frequency Ultrasound

Non-linear contrast-enhanced ultrasound can provide high contrast images by enhancing the non-linear signals from bubble oscillations. In this work, we developed a methodology to detect individual bubble scattering using focused transducers with dilute bubble solutions. Microbubbles and nanobubbles were made with five different lipid shell compositions. Their structure is altered through additional components added to the shell that affect their stability. Dilute samples of bubbles were sonicated at 25 MHz with 30 cycles using a commercial high frequency ultrasound instrument with a pressure range of 75 kPa to 3 MPa. Criteria were developed to ensure signals were only classified if they contained an isolated bubbles’ response. The response of the bubbles of different shell compositions were compared using analysis tools developed. There were no observable differences in the non-linear behaviour between the different shells. However, when comparing microbubbles to nanobubbles differences involving signal count, stability and harmonic amplitudes were observed.

scholarly journals Non-linear Acoustic Characterization of Microbubbles and Nanobubbles

2021 ◽  
Author(s):  
Grace Fishbein ◽  
Michael Kolios
Keyword(s):  
High Frequency Ultrasound ◽  
Contrast Enhanced ◽  
Acoustic Characterization ◽  
Non Linear ◽  
Linear Behaviour ◽  
Linear Contrast ◽  
Bubble Oscillations ◽  
Focused Transducers ◽  
Frequency Ultrasound

Non-linear contrast-enhanced ultrasound can provide high contrast images by enhancing the non-linear signals from bubble oscillations. In this work, we developed a methodology to detect individual bubble scattering using focused transducers with dilute bubble solutions. Microbubbles and nanobubbles were made with five different lipid shell compositions. Their structure is altered through additional components added to the shell that affect their stability. Dilute samples of bubbles were sonicated at 25 MHz with 30 cycles using a commercial high frequency ultrasound instrument with a pressure range of 75 kPa to 3 MPa. Criteria were developed to ensure signals were only classified if they contained an isolated bubbles’ response. The response of the bubbles of different shell compositions were compared using analysis tools developed. There were no observable differences in the non-linear behaviour between the different shells. However, when comparing microbubbles to nanobubbles differences involving signal count, stability and harmonic amplitudes were observed.

Modeling of oscillations of a bubble cluster in an acoustic field

2006 ◽  
Vol 4 ◽  
pp. 174-185
Author(s):  
E.Sh. Nasibullaeva ◽  
I.Sh. Akhatov
Keyword(s):  
Mathematical Model ◽  
Acoustic Field ◽  
Nonlinear Oscillations ◽  
Gas Bubbles ◽  
Single Bubble ◽  
Small Bubble ◽  
Bubble Cluster ◽  
Bubble Oscillations

A mathematical model describing the dynamics of nonlinear oscillations of gas bubbles in a cluster under the influence of an acoustic field is proposed. On the basis of this model, small bubble oscillations in a cluster were analyzed, the bubble oscillations in a monodisperse cluster were compared with the oscillations of a single bubble, the effects of the interaction of bubbles in a polydisperse cluster were studied, and the diffusion stability of bubbles in mono- and polydisperse clusters was investigated.

B. The Non-Linear Calculations for Pulsating Stars

1967 ◽  
Vol 28 ◽  
pp. 105-176
Author(s):  
Robert F. Christy
Keyword(s):  
Major Part ◽  
Afternoon Session ◽  
Discussion Session ◽  
Pulsating Stars ◽  
Fourth Symposium ◽  
Non Linear ◽  
Considerable Discussion ◽  
Informal Approach ◽  
Preceding Session

(Ed. note: The custom in these Symposia has been to have a summary-introductory presentation which lasts about 1 to 1.5 hours, during which discussion from the floor is minor and usually directed at technical clarification. The remainder of the session is then devoted to discussion of the whole subject, oriented around the summary-introduction. The preceding session, I-A, at Nice, followed this pattern. Christy suggested that we might experiment in his presentation with a much more informal approach, allowing considerable discussion of the points raised in the summary-introduction during its presentation, with perhaps the entire morning spent in this way, reserving the afternoon session for discussion only. At Varenna, in the Fourth Symposium, several of the summaryintroductory papers presented from the astronomical viewpoint had been so full of concepts unfamiliar to a number of the aerodynamicists-physicists present, that a major part of the following discussion session had been devoted to simply clarifying concepts and then repeating a considerable amount of what had been summarized. So, always looking for alternatives which help to increase the understanding between the different disciplines by introducing clarification of concept as expeditiously as possible, we tried Christy's suggestion. Thus you will find the pattern of the following different from that in session I-A. I am much indebted to Christy for extensive collaboration in editing the resulting combined presentation and discussion. As always, however, I have taken upon myself the responsibility for the final editing, and so all shortcomings are on my head.)

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