Nonlinear second- and first-sound wave equations in3He−4Hemixtures

Piezoelectric transducer with negative impedance matching circuit is put forward to enhance its performance in broadband frequencies. The typical multi-physics problem is coupled with sound wave equations, structure stress-strain equations, piezoelectric constitutive equations and electric ordinary equations, and it is analyzed with FEM in detail. Frequency response characteristics are simulated when shunted with negative-impedance in series. When proper negative synthesized elements are connected, the performance of low frequencies and bandwidth are enhanced obviously.

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A Novel Theoretical Modeling for Predicting the Sound Absorption of Woven Fabrics Using Modification of Sound Wave Equation and Genetic Algorithm

Autex Research Journal ◽

10.2478/aut-2020-0060 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Valentinus Galih Vidia Putra ◽

Irwan ◽

Andrian Wijayono ◽

JulianyNingsih Mohamad ◽

Yusril Yusuf

Keyword(s):

Genetic Algorithms ◽

Wave Equation ◽

Absorption Coefficient ◽

Sound Wave ◽

Sound Absorption ◽

Wave Equations ◽

Woven Fabrics ◽

Woven Fabric ◽

Sound Absorption Coefficient ◽

New Model

Abstract Woven fabric in Indonesia is generally known as a material for making clothes and it has been applied as an interior finishing material in buildings, such as sound absorbent material. This study presents a new method for predicting the sound absorption of woven fabrics using a modification of the wave equations and using genetic algorithms. The main aim of this research is to study the sound absorption properties of woven fabric by modeling using a modification of the sound wave equations and using genetic algorithms. A new model for predicting the sound absorption coefficient of woven fabric (plain, twill 2/1, rips and satin fabric) as a function of porosity, the weight of the fabric, the thickness of the fabric, and frequency of the sound wave, was determined in this paper. In this research, the sound absorption coefficient equation was obtained using the modification of the sound wave equation as well as using genetic algorithms. This new model included the influence of the sound absorption coefficient phenomenon caused by porosity, the weight of the fabric, the thickness of fabric as well as the frequency of the sound wave. In this study, experimental data showed a good agreement with the model

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Simulation of Sound Wave Propagation With Damping for Realistic Sound rendering for Games and Interactive Applications

PsycEXTRA Dataset ◽

10.1037/e582722013-020 ◽

2012 ◽

Author(s):

Bruno Moreira ◽

Mauricio Kischinhevsky ◽

Marcelo Zamith ◽

Esteban Clua ◽

Diego Brandao

Keyword(s):

Wave Propagation ◽

Sound Wave ◽

Interactive Applications ◽

Sound Rendering

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Remarks on nonlinear elastic waves with null conditions

ESAIM Control Optimisation and Calculus of Variations ◽

10.1051/cocv/2020039 ◽

2020 ◽

Vol 26 ◽

pp. 121

Author(s):

Dongbing Zha ◽

Weimin Peng

Keyword(s):

Initial Data ◽

Global Existence ◽

Elastic Waves ◽

Wave Equations ◽

Alternative Proof ◽

Classical Solutions ◽

Small Initial Data ◽

Hyperelastic Materials ◽

Variational Structure ◽

Nonlinear Elastic

For the Cauchy problem of nonlinear elastic wave equations for 3D isotropic, homogeneous and hyperelastic materials with null conditions, global existence of classical solutions with small initial data was proved in R. Agemi (Invent. Math. 142 (2000) 225–250) and T. C. Sideris (Ann. Math. 151 (2000) 849–874) independently. In this paper, we will give some remarks and an alternative proof for it. First, we give the explicit variational structure of nonlinear elastic waves. Thus we can identify whether materials satisfy the null condition by checking the stored energy function directly. Furthermore, by some careful analyses on the nonlinear structure, we show that the Helmholtz projection, which is usually considered to be ill-suited for nonlinear analysis, can be in fact used to show the global existence result. We also improve the amount of Sobolev regularity of initial data, which seems optimal in the framework of classical solutions.

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On the Exact Soliton Solutions of Some Nonlinear PDE by Tan-Cot Method

GUB Journal of Science and Engineering ◽

10.3329/gubjse.v5i1.47898 ◽

2018 ◽

Vol 5 (1) ◽

pp. 31-36

Author(s):

Md Monirul Islam ◽

Muztuba Ahbab ◽

Md Robiul Islam ◽

Md Humayun Kabir

Keyword(s):

Solitary Wave ◽

Acoustic Waves ◽

Water Waves ◽

Wave Equations ◽

Rectangular Channel ◽

Soliton Solutions ◽

Boussinesq Equations ◽

Travelling Wave ◽

Ion Acoustic Waves ◽

Analytical System

For many solitary wave applications, various approximate models have been proposed. Certainly, the most famous solitary wave equations are the K-dV, BBM and Boussinesq equations. The K-dV equation was originally derived to describe shallow water waves in a rectangular channel. Surprisingly, the equation also models ion-acoustic waves and magneto-hydrodynamic waves in plasmas, waves in elastic rods, equatorial planetary waves, acoustic waves on a crystal lattice, and more. If we describe all of the above situation, we must be needed a solution function of their governing equations. The Tan-cot method is applied to obtain exact travelling wave solutions to the generalized Korteweg-de Vries (gK-dV) equation and generalized Benjamin-Bona- Mahony (BBM) equation which are important equations to evaluate wide variety of physical applications. In this paper we described the soliton behavior of gK-dV and BBM equations by analytical system especially using Tan-cot method and shown in graphically. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 5(1), Dec 2018 P 31-36

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Extended F-Expansion Method for Solving the modified Korteweg-de Vries (mKdV) Equation

Al-Jabar Jurnal Pendidikan Matematika ◽

10.24042/ajpm.v11i1.5153 ◽

2020 ◽

Vol 11 (1) ◽

pp. 93-100

Author(s):

Vina Apriliani ◽

Ikhsan Maulidi ◽

Budi Azhari

Keyword(s):

Wave Equation ◽

Exact Solutions ◽

Internal Waves ◽

Water Waves ◽

Wave Equations ◽

Elliptic Functions ◽

Expansion Method ◽

Mkdv Equation ◽

Innovative Methods ◽

De Vries

One of the phenomenon in marine science that is often encountered is the phenomenon of water waves. Waves that occur below the surface of seawater are called internal waves. One of the mathematical models that can represent solitary internal waves is the modified Korteweg-de Vries (mKdV) equation. Many methods can be used to construct the solution of the mKdV wave equation, one of which is the extended F-expansion method. The purpose of this study is to determine the solution of the mKdV wave equation using the extended F-expansion method. The result of solving the mKdV wave equation is the exact solutions. The exact solutions of the mKdV wave equation are expressed in the Jacobi elliptic functions, trigonometric functions, and hyperbolic functions. From this research, it is expected to be able to add insight and knowledge about the implementation of the innovative methods for solving wave equations.

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Technical Note. Influence of Material Used for the Regenerator on the Properties of a Thermoacoustic Heat Pump

Archives of Acoustics ◽

10.2478/aoa-2013-0067 ◽

2013 ◽

Vol 38 (4) ◽

pp. 565-570 ◽

Cited By ~ 2

Author(s):

Bartłomiej Kruk

Keyword(s):

Heat Transfer ◽

Temperature Gradient ◽

Acoustic Wave ◽

Heat Pump ◽

Sound Wave ◽

Heat Exchangers ◽

Heat Pumps ◽

Technical Note ◽

New Materials ◽

Modern Technologies

Abstract Research in termoacoustics began with the observation of the heat transfer between gas and solids. Using this interaction the intense sound wave could be applied to create engines and heat pumps. The most important part of thermoacoustic devices is a regenerator, where press of conversion of sound energy into thermal or vice versa takes place. In a heat pump the acoustic wave produces the temperature difference at the two ends of the regenerator. The aim of the paper is to find the influence of the material used for the construction of a regenerator on the properties of a thermoacoustic heat pump. Modern technologies allow us to create new materials with physical properties necessary to increase the temperature gradient on the heat exchangers. The aim of this paper is to create a regenerator which strongly improves the efficiency of the heat pump.

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Instability and Collapse in Discrete Wave Equations

Computational Methods in Applied Mathematics ◽

10.2478/cmam-2005-0011 ◽

2005 ◽

Vol 5 (3) ◽

pp. 223-241

Author(s):

A. Carpio ◽

G. Duro

Keyword(s):

Continuum Limit ◽

Wave Equations ◽

Numerical Solutions ◽

Blow Up ◽

Theoretical Predictions ◽

Initial States ◽

The Impact ◽

The Continuum

AbstractUnstable growth phenomena in spatially discrete wave equations are studied. We characterize sets of initial states leading to instability and collapse and obtain analytical predictions for the blow-up time. The theoretical predictions are con- trasted with the numerical solutions computed by a variety of schemes. The behavior of the systems in the continuum limit and the impact of discreteness and friction are discussed.

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