Poroacoustic acceleration waves

2006 ◽  
Vol 462 (2075) ◽  
pp. 3493-3499 ◽  
Author(s):  
M Ciarletta ◽  
B Straughan
Keyword(s):  
Porous Medium ◽  
Acoustic Waves ◽  
Building Industry ◽  
Acceleration Wave ◽  
Acceleration Waves ◽  
Continuum Thermodynamic ◽  
Thermodynamic Derivation

A model for acoustic waves in a porous medium is investigated. Due to the use of lighter materials in modern buildings and noise concerns in the environment, such models for poroacoustic waves are of much interest to the building industry. The model has been investigated in some detail by P. M. Jordan. Here we present a rational continuum thermodynamic derivation of the Jordan model. We then present results for the amplitude of an acceleration wave making no approximations whatsoever.

Growth and decay of acoustic acceleration waves in Darcy-type porous media

2005 ◽  
Vol 461 (2061) ◽  
pp. 2749-2766 ◽  
Author(s):  
P.M Jordan
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Acoustic Waves ◽  
Blow Up ◽  
Equation Of Motion ◽  
Travelling Wave ◽  
Finite Amplitude ◽  
Numerical Work ◽  
Hyperbolic Form ◽  
Acceleration Waves

The propagation of acoustic waves in a fluid that saturates a Darcy-type porous medium is considered under finite-amplitude theory. The equation of motion is derived, an acceleration wave analysis is carried out, and a travelling wave solution (TWS) is obtained. In addition, analytical findings are supported with numerical work generated by a simple, but effective, finite-difference scheme and results obtained are compared with those of the nonporous and linear cases. Most notably, this analysis reveals the following: (i) that the equation of motion is a new, hyperbolic form of Kuznetsov's equation; (ii) that finite-time blow-up of the wave amplitude is possible even if dissipation is present; (iii) the presence of a porous medium increases, with respect to the nonporous case, the rate at which amplitude growth/decay occurs; (iv) in the case of porous media propagation, not all compressive acceleration waves suffer blow up; and (v) that there exists a connection between acceleration waves and TWSs.

Mass and heat transfer in the problem of propagation of acoustic waves in a porous medium

2012 ◽  
Vol 9 (1) ◽  
pp. 139-141
Author(s):  
L.F. Sitdikova ◽  
V.L. Dmitriev
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Acoustic Waves ◽  
Heat Conduction Equation ◽  
Wave Processes ◽  
Common System ◽  
Inner Surface ◽  
Fast And Slow Waves ◽  
Mass And Heat Transfer ◽  
Velocity Approximation

The paper is devoted to a theoretical investigation of wave processes in moist porous media saturated with gas. Interfacial forces of interaction, heat exchange between the skeleton of a porous medium, liquid and gas, mass transfer between a liquid and a gas; material of the skeleton of a porous medium is considered viscoelastic, the liquid covers the inner surface of the pores of the medium with a thin uniform layer. The propagation of acoustic waves is considered in the two-velocity approximation. A common system is recorded equations and physical relationships describing the propagation of acoustic waves in a wet porous medium. A dispersion relation is obtained. Influence of heat transfer between phases on propagation ”Fast“ and ”slow“ waves is taken into account on the basis of the heat conduction equation.

Propagation of acoustic waves in layered porous media

2007 ◽  
Vol 5 ◽  
pp. 169-175
Author(s):  
V.L. Dmitriev ◽  
Е.А. Ponomareva
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Dispersion Relation ◽  
Acoustic Waves ◽  
Saturated Liquid ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Layered Porous Media ◽  
The Media

The paper considers the processes of reflection and transmission acoustic waves at the interface between two porous media, saturated liquid or gas. The cases of a porous medium whose layers have the same porosity, but are saturated with different fluids. Based The dispersion relation and the conditions at the interface between the media are obtained reflection and transmission coefficients. The possibility determination of the parameters of the porous material and its saturating fluid based on the signal reflected from the interface.

scholarly journals Acceleration Waves in Rational Extended Thermodynamics of Rarefied Monatomic Gases

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 139
Author(s):  
Francesca Brini ◽  
Leonardo Seccia
Keyword(s):  
Shock Wave ◽  
Extended Thermodynamics ◽  
Rarefied Gases ◽  
Acceleration Wave ◽  
One Dimensional ◽  
Acceleration Waves ◽  
Rational Extended Thermodynamics ◽  
Monatomic Gas ◽  
Non Equilibrium

Rational Extended Thermodynamics theories with different number of moments are usually introduced to study non-equilibrium phenomena in rarefied gases. Here, we use them to describe one-dimensional acceleration waves in a rarefied monatomic gas. In particular, we focus on the degeneracy of the acceleration wave to a shock wave, in order to test the validity of the models and the role played by an increasing number of moments. As a byproduct, some peculiarities of the characteristic velocities at equilibrium are analyzed as well.

Evolution of acoustic waves in channels with permeable-wall regions in an inhomogeneous porous medium

2002 ◽  
Vol 48 (3) ◽  
pp. 254-262
Author(s):  
Z. A. Bulatova ◽  
G. A. Gumerova ◽  
V. Sh. Shagapov
Keyword(s):  
Porous Medium ◽  
Acoustic Waves ◽  
Permeable Wall ◽  
Inhomogeneous Porous Medium
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