Sound propagation in water containing large tethered spherical encapsulated gas bubbles with resonance frequencies in the 50 Hz to 100 Hz range

2011 ◽  
Vol 130 (5) ◽  
pp. 3325-3332 ◽  
Author(s):  
Kevin M. Lee ◽  
Kevin T. Hinojosa ◽  
Mark S. Wochner ◽  
Theodore F. Argo ◽  
Preston S. Wilson ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Gas Bubbles ◽  
Resonance Frequencies

Pressure and Shock Waves in Bubbly Liquids

2015 ◽  
Author(s):  
Shahid Mahmood ◽  
Yungpil Yoo ◽  
Ho-Young Kwak
Keyword(s):  
Wave Propagation ◽  
Wave Equation ◽  
Dispersion Relation ◽  
Sound Propagation ◽  
Relaxation Oscillation ◽  
Bubbly Flow ◽  
Gas Bubbles ◽  
Bubbly Liquid ◽  
Bubbly Liquids ◽  
Pressure Profiles

It is well known that sound propagation in liquid media is strongly affected by the presence of gas bubbles that interact with sound and in turn affect the medium. An explicit form of a wave equation in a bubbly liquid medium was obtained in this study. Using the linearized wave equation and the Keller-Miksis equation for bubble wall motion, a dispersion relation for the linear pressure wave propagation in bubbly liquids was obtained. It was found that attenuation of the waves in bubbly liquid occurs due to the viscosity and the heat transfer from/to the bubble. In particular, at the lower frequency region, the thermal diffusion has a considerable affect on the frequency-dependent attenuation coefficients. The phase velocity and the attenuation coefficient obtained from the dispersion relation are in good agreement with the observed values in all sound frequency ranges from kHz to MHz. Shock wave propagation in bubbly mixtures was also considered with the solution of the wave equation, whose particular solution represents the interaction between bubbles. The calculated pressure profiles are in close agreement with those obtained in shock tube experiments for a uniform bubbly flow. Heat exchange between the gas bubbles and the liquid and the interaction between bubbles were found to be very important factor to affect the relaxation oscillation behind the the shock front.

Acoustic behavior of large encapsulated gas bubbles with resonance frequencies in the 50 to 100 Hz range

2010 ◽  
Author(s):  
Mark S. Wochner ◽  
Kevin T. Hinojosa ◽  
Kevin Lee ◽  
Theodore F. Argo IV ◽  
Preston S. Wilson ◽  
...  
Keyword(s):  
Gas Bubbles ◽  
Acoustic Behavior ◽  
Resonance Frequencies

On the Apparent Propagation Speed in Transmission Line Matrix Uniform Grid Meshes

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Alexandre S. Brandão ◽  
Edson Cataldo ◽  
Fabiana R. Leta
Keyword(s):  
Transmission Line ◽  
Sound Propagation ◽  
Vocal Tract ◽  
Numerical Models ◽  
A Priori ◽  
Three Dimensional ◽  
Propagation Speed ◽  
Uniform Grid ◽  
Transmission Line Matrix ◽  
Resonance Frequencies

Numerical models consisting of two-dimensional (2D) and three-dimensional (3D) uniform grid meshes for the transmission line matrix method (TLM) currently use 2 and 3, respectively, to compensate for the apparent sound speed. In this paper, new compensation factors are determined from a priori simulations, performed without compensation, in 2D and 3D TLM one-section tube models. The frequency values of the first mistuned resonance peaks, obtained from these simulations, are substituted in the corresponding equations for the resonance frequencies in one-section tubes to find the apparent sound propagation speed in the mesh environment and, thus, the necessary compensation. The new factors have been tested in more complex models like a two-tube concatenation model and a realistic magnetic resonance imaging (MRI)-reconstructed human vocal tract (VT) model. Important VT modeling results confirm the improvement over the conventional compensation factors, particularly for frequencies above 4 kHz. Among these results are the identification of the spectral trough at about 5200 Hz caused by the piriform fossa and the application of a pitch extraction algorithm to the 3D TLM output signal, finding a difference smaller than 0.66% relatively to human voice pitch.

Acoustic behavior of large encapsulated gas bubbles with resonance frequencies in the 50–100 Hz range.

2010 ◽  
Vol 127 (3) ◽  
pp. 2015-2015
Author(s):  
Mark S. Wochner ◽  
Kevin T. Hinojosa ◽  
Kevin M. Lee ◽  
Theodore F. Argo ◽  
Preston S. Wilson ◽  
...  
Keyword(s):  
Gas Bubbles ◽  
Acoustic Behavior ◽  
Resonance Frequencies

Microstreaming generated by two acoustically induced gas bubbles

2016 ◽  
Vol 796 ◽  
pp. 318-339 ◽  
Author(s):  
Alexander A. Doinikov ◽  
Ayache Bouakaz
Keyword(s):  
Numerical Simulations ◽  
Acoustic Field ◽  
Considerable Increase ◽  
Gas Bubbles ◽  
Stress Fields ◽  
Resonance Frequencies ◽  
Bubble Sizes

A theory is developed that describes microstreaming generated by two interacting gas bubbles in an acoustic field. The theory is used in numerical simulations to compare the characteristics of acoustic microstreaming at different frequencies, separation distances between the bubbles and bubble sizes. It is shown that the interaction of the bubbles leads to a considerable increase in the intensity of the velocity and stress fields of acoustic microstreaming if the bubbles are driven near the resonance frequencies that they have in the presence of each other. Patterns of streamlines for different situations are presented.

Fission Gas Bubbles in Fractured UO2

1968 ◽  
Vol 26 ◽  
pp. 286-287
Author(s):  
O. M. Katz
Keyword(s):  
Electron Microscopy ◽  
Thermal Gradient ◽  
Gas Bubbles ◽  
Inert Gas ◽  
Thermal Gradients ◽  
Fission Gas ◽  
Beam Heating ◽  
Limited Application ◽  
Bubble Characteristics ◽  
Electron Beam Heating

The swelling of irradiated UO2 has been attributed to the migration and agglomeration of fission gas bubbles in a thermal gradient. High temperatures and thermal gradients obtained by electron beam heating simulate reactor behavior and lead to the postulation of swelling mechanisms. Although electron microscopy studies have been reported on UO2, two experimental procedures have limited application of the results: irradiation was achieved either with a stream of inert gas ions without fission or at depletions less than 2 x 1020 fissions/cm3 (∼3/4 at % burnup). This study was not limited either of these conditions and reports on the bubble characteristics observed by transmission and fractographic electron microscopy in high density (96% theoretical) UO2 irradiated between 3.5 and 31.3 x 1020 fissions/cm3 at temperatures below l600°F. Preliminary results from replicas of the as-polished and etched surfaces of these samples were published.

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