Interaction of an acoustic wave with a multilayer medium containing a bubble liquid layer

2019 ◽  
Vol 14 (4) ◽  
pp. 233-242
Author(s):  
U.O. Agisheva ◽  
M.N. Galimzyanov
Keyword(s):  
Acoustic Waves ◽  
Wave Dispersion ◽  
Point Of View ◽  
Bubble Medium ◽  
Existence Of A Solution ◽  
Reflection And Transmission ◽  
Bubble Liquid ◽  
Carrier Liquid ◽  
Transmitted Waves ◽  
Layer Medium

Discrete-layered media are interesting to research since properties of each layer can significantly differ from near by ones and this can be used in technological processes. The presence of a small number of bubbles significantly increases the compressibility of the medium while the density of the bubble medium remains close to the density of the carrier liquid. From the applied point of view it is interesting that the energy of the incident wave can be completely absorbed by combining of layer properties (length, volume content of the dispersed phase, etc.). In this work, based on the equations of mechanics of dispersed media, we consider the reflection and propagation of acoustic waves passing at right angles through a three-layer medium in a pipeline containing a layer of bubble fluid. From the condition for the existence of a solution in the form of a decaying traveling wave, dispersion relations are written for each of the possible layers. Based on them, the dependences of the amplitude of the incident and transmitted waves on the propagation velocity of the pulse are analytically derived. The coefficients of reflection and transmission through the interface are obtained both in the general case and in particular cases for each layer. These ratios make it possible to calculate the possible consequences of a wave action on the considered media in the event of emergencies at work and to prevent them.

Propagation and interaction with obstructions of acoustic waves in vapor-gas-liquid media

2012 ◽  
Vol 9 (1) ◽  
pp. 121-124
Author(s):  
A.A. Nikiforov
Keyword(s):  
Acoustic Waves ◽  
Rigid Wall ◽  
Bubble Medium ◽  
Liquid Media ◽  
Reflection And Transmission ◽  
Initial Wave ◽  
The Waves ◽  
Analytical Expressions ◽  
Transmission And Reflection

Transmission and reflection of acoustic waves from a layer of a bubble medium into a liquid is theoretically studied, with subsequent reflection of the waves that arise from the rigid wall. The amplitudes of the emerging waves are determined through the amplitude of the initial wave, analytical expressions are obtained for the coefficients of reflection and transmission of waves across the interfaces.

Attenuation of longitudinal electro-acoustic waves in a plasma

1974 ◽  
Vol 11 (1) ◽  
pp. 37-49
Author(s):  
R. J. Papa ◽  
P. Lindstrom
Keyword(s):  
Dispersion Relation ◽  
Electric Field ◽  
Acoustic Waves ◽  
Collision Frequency ◽  
Wave Dispersion ◽  
Signal Frequency ◽  
Variable Theory ◽  
Longitudinal Waves ◽  
Confluent Hypergeometric Functions ◽  
Linearized Boltzmann Equation

There are several practical situations in partially ionized plasmas when both collisionless (Landau) damping and electron-neutral collisions contribute to the attenuation of longitudinal waves. The longitudinal-wave dispersion relation is derived from Maxwell's equations and the linearized Boltzmann equation, in which electron-neutral collisions are represented by a Bhatnagar–Gross–Krook model that conserves particles locally. (The dispersion relation predicts that, for a given signal frequency ώ), an infinite number of complex wavenumbers kn can exist. Using Fourier–Laplace transform techniques, an integral representation for the electric field of the longitudinal waves is readily derived. Then, using theorems from complex variable theory, a modal expansion of the electric field can be made in terms of an infinite sum of confluent hypergeometric functions, whose arguments are proportional to the complex wavenumbers kn. It is demonstrated numerically that the spatial integral of the square of the electric field amplitude decreases as the electron-neutral collision frequency increases. Also, the amount of energy contained in the first few (lowest) modes, and the coupling between the modes, is examined as a function of plasma frequency, signal frequency and collision frequency.

The Sound of Thought

2016 ◽  
Author(s):  
Andrea Moro
Keyword(s):  
Acoustic Waves ◽  
Point Of View ◽  
Awake Surgery ◽  
Surprising Result ◽  
Crucial Experiment ◽  
Linguistic Expression ◽  
Physical Point ◽  
The Brain ◽  
Electric Waves

From a physical point of view, language is made of waves: acoustic waves (outside us) and electric waves (inside us). How similar are these two types of waves? By exploiting awake surgery procedures a crucial experiment is described confronting these two types of waves when a patient reads a linguistic expression aloud or silently. The surprising result is that the two electric waves are very similar even in non acoustic areas opening the possibility to read the linguistic thought directly from the brain.

scholarly journals Reflection and Transmission of Acoustic Waves through the Layer of Multifractional Bubbly Liquid

2018 ◽  
Vol 148 ◽  
pp. 15001
Author(s):  
Damir Anvarovich Gubaidullin ◽  
Ramil Nakipovich Gafiyatov
Keyword(s):  
Acoustic Waves ◽  
Wave Reflection ◽  
Water Model ◽  
Bubbly Liquid ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Multilayer Medium ◽  
Bubble Layer ◽  
The Mathematical Model ◽  
Theoretical Results

The mathematical model that determines reflection and transmission of acoustic wave through a medium containing multifractioanl bubbly liquid is presented. For the water-water with bubbles-water model the wave reflection and transmission coefficients are calculated. The influence of the bubble layer thickness on the investigated coefficients is shown. The theory compared with the experiment. It is shown that the theoretical results describe and explain well the available experimental data. It is revealed that the special dispersion and dissipative properties of the layer of bubbly liquid can significantly influence on the reflection and transmission of acoustic waves in multilayer medium

Conservative Finite-Difference Scheme for High-Frequency Acoustic Waves Propagating at an Interface Between Two Media

2012 ◽  
Vol 11 (2) ◽  
pp. 351-366
Author(s):  
J. Staudacher ◽  
É Savin
Keyword(s):  
Phase Space ◽  
Acoustic Waves ◽  
High Frequency ◽  
Numerical Scheme ◽  
Propagation Model ◽  
Uniform Grid ◽  
Two Dimensional ◽  
Reflection And Transmission ◽  
Conservative Finite Difference Scheme ◽  
Homogeneous Media

AbstractThis paper is an introduction to a conservative, positive numerical scheme which takes into account the phenomena of reflection and transmission of high frequency acoustic waves at a straight interface between two homogeneous media. Explicit forms of the interpolation coefficients for reflected and transmitted wave vectors on a two-dimensional uniform grid are derived. The propagation model is a Liouville transport equation solved in phase space.

scholarly journals A proof that multiple waves propagate in ensemble-averaged particulate materials

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190344 ◽  
Author(s):  
Artur L. Gower ◽  
I. David Abrahams ◽  
William J. Parnell
Keyword(s):  
Acoustic Waves ◽  
Volume Fraction ◽  
Effective Medium Theory ◽  
Effective Medium ◽  
Inhomogeneous Material ◽  
Ensemble Averaging ◽  
Reflection And Transmission ◽  
Medium Theory ◽  
Transmission Coefficients ◽  
Cylindrical Inclusions

Effective medium theory aims to describe a complex inhomogeneous material in terms of a few important macroscopic parameters. To characterize wave propagation through an inhomogeneous material, the most crucial parameter is the effective wavenumber . For this reason, there are many published studies on how to calculate a single effective wavenumber. Here, we present a proof that there does not exist a unique effective wavenumber; instead, there are an infinite number of such (complex) wavenumbers. We show that in most parameter regimes only a small number of these effective wavenumbers make a significant contribution to the wave field. However, to accurately calculate the reflection and transmission coefficients, a large number of the (highly attenuating) effective waves is required. For clarity, we present results for scalar (acoustic) waves for a two-dimensional material filled (over a half-space) with randomly distributed circular cylindrical inclusions. We calculate the effective medium by ensemble averaging over all possible inhomogeneities. The proof is based on the application of the Wiener–Hopf technique and makes no assumption on the wavelength, particle boundary conditions/size or volume fraction. This technique provides a simple formula for the reflection coefficient, which can be explicitly evaluated for monopole scatterers. We compare results with an alternative numerical matching method.

Effective Dynamic Properties and Multi-Resonant Design of Acoustic Metamaterials

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
R. Zhu ◽  
G. L. Huang ◽  
G. K. Hu
Keyword(s):  
Dynamic Properties ◽  
Wave Dispersion ◽  
Wave Band ◽  
Energy Transfer Mechanism ◽  
Acoustic Metamaterials ◽  
Multiple Wave ◽  
Reflection And Transmission ◽  
Acoustic Metamaterial ◽  
Effective Dynamic ◽  
The Difference

In the study, a retrieval approach is extended to determine the effective dynamic properties of a finite multilayered acoustic metamaterial based on the theoretical reflection and transmission analysis. The accuracy of the method is verified through a comparison of wave dispersion curve predictions from the homogeneous effective medium and the exact solution. A multiresonant design is then suggested for the desirable multiple wave band gaps by using a finite acoustic metamaterial slab. Finally, the band gap behavior and kinetic energy transfer mechanism in a multilayered composite with a periodic microstructure are studied to demonstrate the difference between the Bragg scattering mechanism and the locally resonant mechanism.

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