Pulse distortion of a signal passing through a bubble cloud

2003 ◽  
Vol 114 (4) ◽  
pp. 2372-2372
Author(s):  
Ralph R. Goodman ◽  
Jerald W. Caruthers
Keyword(s):  
Bubble Cloud ◽  
Pulse Distortion

Water Treatment using Discharge Generated in Cavitation Field with Micro Bubble Cloud

2012 ◽  
Vol 132 (8) ◽  
pp. 656-663 ◽  
Author(s):  
Satoshi Ihara ◽  
Taiki Hirohata ◽  
Yuichi Kominato ◽  
Chobei Yamabe ◽  
Hideaki Ike ◽  
...  
Keyword(s):  
Water Treatment ◽  
Bubble Cloud ◽  
Cavitation Field ◽  
Micro Bubble

scholarly journals Cavitation Bubble Cloud Break-Off Mechanisms at Micro-Channels

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 215
Author(s):  
Paul McGinn ◽  
Daniel Pearce ◽  
Yannis Hardalupas ◽  
Alex Taylor ◽  
Konstantina Vogiatzaki
Keyword(s):  
Cavitation Bubble ◽  
Cavitation Inception ◽  
Wave Dynamics ◽  
Bubble Cloud ◽  
Cloud Dynamics ◽  
Micro Channels ◽  
Physical Insight ◽  
Cloud Process ◽  
Good Agreement

This paper provides new physical insight into the coupling between flow dynamics and cavitation bubble cloud behaviour at conditions relevant to both cavitation inception and the more complex phenomenon of flow “choking” using a multiphase compressible framework. Understanding the cavitation bubble cloud process and the parameters that determine its break-off frequency is important for control of phenomena such as structure vibration and erosion. Initially, the role of the pressure waves in the flow development is investigated. We highlight the differences between “physical” and “artificial” numerical waves by comparing cases with different boundary and differencing schemes. We analyse in detail the prediction of the coupling of flow and cavitation dynamics in a micro-channel 20 m high containing Diesel at pressure differences 7 MPa and 8.5 MPa, corresponding to cavitation inception and "choking" conditions respectively. The results have a very good agreement with experimental data and demonstrate that pressure wave dynamics, rather than the “re-entrant jet dynamics” suggested by previous studies, determine the characteristics of the bubble cloud dynamics under “choking” conditions.

Bubble cloud configuration effect on the added mass

2021 ◽  
Vol 33 (5) ◽  
pp. 053304
Author(s):  
S. Zoghlami ◽  
C. Béguin ◽  
A. Teyssedou ◽  
D. Scott ◽  
L. Bornard ◽  
...  
Keyword(s):  
Added Mass ◽  
Bubble Cloud

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.

Multibunch accelerator operation with RF pulse distortion

1990 ◽  
Author(s):  
T.L. Houck ◽  
G.D. Craig ◽  
G.A. Westenskow ◽  
S.S. Yu ◽  
A.E. Vlieks
Keyword(s):  
Pulse Distortion ◽  
Rf Pulse

Pulse Distortion in Resonant and Nonresonant Gases

Radio Science ◽  
1970 ◽  
Vol 5 (11) ◽  
pp. 1301-1305 ◽  
Author(s):  
L. E. Vogler
Keyword(s):  
Pulse Distortion

Cavitation dynamics of histotripsy bubble cloud nucleated from echogenic liposomes

2021 ◽  
Vol 150 (4) ◽  
pp. A29-A29
Author(s):  
Aarushi Bhargava ◽  
Shaoling Huang ◽  
David D. McPherson ◽  
Kenneth B. Bader
Keyword(s):  
Bubble Cloud ◽  
Echogenic Liposomes

A Study on the Hydrodynamic Load in a Water Pool When Discharged Air Forms a Bubble Cloud

2006 ◽  
Author(s):  
Ken Uchida ◽  
Seijiro Suzuki
Keyword(s):  
Void Fraction ◽  
Pressure Oscillation ◽  
Numerical Results ◽  
Numerical Dissipation ◽  
Hydrodynamic Load ◽  
Water Pool ◽  
Two Phase ◽  
Bubble Cloud ◽  
Water Region ◽  
Media Layer

This paper presents a numerical and qualitative study on the expected hydrodynamic load-reducing effect of bubbly media near a volumetrically oscillating bubble. In this study, the bubble or bubble cloud is assumed to be spherically symmetric, and its motion is analyzed as a one-dimensional compressible two-phase flow in the radial direction in spherical coordinates. We adopted the CCUP (CIP-Combined Unified Procedure) method, which is a unified analysis method for both compressible and incompressible fluids proposed by Yabe et al. (1991) in order to treat interaction among gas, liquid, and two-phase media, and to avoid large numerical dissipation at density discontinuities. To verify the analysis program we developed, we analyzed free oscillations of a bubble with a unity void fraction and of a bubble cloud with an initial void fraction of 0.5, and found that the natural frequency from numerical results are well reproduced with an error of 0.9% for the bubble and 5% for the bubble cloud as compared to those obtained on a theoretical basis. Using this method, we analyzed the free oscillation of a bubble cloud in which a bubble with a unity void fraction is covered by a bubbly media layer with an initial void fraction of 0.5. Numerical results show that the amplitude of pressure oscillation inside the bubble is about halved, and that a higher mode of oscillation appears when a bubbly media layer covers the bubble. The measured results from a blowdown test we previously reported also shows a similar higher mode of oscillation. The amplitude of pressure oscillation in the water region was apparently reduced when a thick bubbly media layer covers the bubble. Thus, if the bubbly media is ejected from sparger holes prior to the ejection of a high-pressure bubble, the bubbly media might reduce the hydrodynamic load induced in a water pool made by volumetric oscillation of the bubble.

Pressure measurement and high-speed observation on the cavitation bubble cloud due to the backscattering of HIFU from a laser-induced bubble

2018 ◽  
Vol 50 (6) ◽  
pp. 065512 ◽  
Author(s):  
Toshiyuki Ogasawara ◽  
Taisei Horiba ◽  
Taisuke Sano ◽  
Hiroyuki Takahira
Keyword(s):  
Pressure Measurement ◽  
Cavitation Bubble ◽  
High Speed ◽  
Bubble Cloud
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