Journal articles: 'Nonlinean acoustics'

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Shao, Jianwang, Tao Zeng, and Xian Wu. "Study of a Nonlinear Membrane Absorber Applied to 3D Acoustic Cavity for Low Frequency Broadband Noise Control." Materials 12, no. 7 (April 8, 2019): 1138. http://dx.doi.org/10.3390/ma12071138.

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As a new approach to passive noise control in low frequency domain, the targeted energy transfer (TET) technique has been applied to the 3D fields of acoustics. The nonlinear membrane absorber based on the TET can reduce the low frequency noise inside the 3D acoustic cavity. The TET phenomenon inside the 3D acoustic cavity has firstly investigated by a two degrees-of-freedom (DOF) system, which is comprised by an acoustic mode and a nonlinear membrane without the pre-stress. In order to control the low frequency broadband noise inside 3D acoustic cavity and consider the influence of the pre-stress for the TET, a general model of the system with several acoustic modes of 3D acoustic cavity and one nonlinear membrane is built and studied in this paper. By using the harmonic balance method and the numerical method, the nonlinear normal modes and the forced responses are analyzed. Meanwhile, the influence of the pre-stress of the nonlinear membrane for the TET is investigated. The desired working zones of the nonlinear membrane absorber for the broadband noise are investigated. It can be helpful to design the nonlinear membrane according the dimension of 3D acoustic cavity to control the low frequency broadband noise.

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Klepka, Andrzej, Wieslaw Jerzy Staszewski, T. Uhl, Dario di Maio, Fabrizio Scarpa, and K. F. Tee. "Impact Damage Detection in Composite Chiral Sandwich Panels." Key Engineering Materials 518 (July 2012): 160–67. http://dx.doi.org/10.4028/www.scientific.net/kem.518.160.

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This paper demonstrates impact damage detection in a composite sandwich panel. The panel is built from a chiral honeycomb and two composite skins. Chiral structures are a subset of auxetic solids exhibiting counterintuitive deformation mechanism and rotative but not reflective symmetry. Damage detection is performed using nonlinear acoustics,involves combined vibro-acoustic interaction of high-frequency ultrasonic wave and low-frequency vibration excitation. High-and low-frequency excitations are introduced to the panel using a low-profile piezoceramic transducer and an electromagnetic shaker, respectively. Vibro-acoustic modulated responses are measured using laser vibrometry. The methods used for impact damage detection clearly reveal de-bonding in the composite panel. The high-frequency weak ultrasonic wave is also modulated by the low-frequency strong vibration wave when nonlinear acoustics is used for damage detection. As a result frequency sidebands can be observed around the main acoustic harmonic in the spectrum of the ultrasonic signal.

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Lee. "Underwater Acoustic Communication Using Nonlinear Chirp Signal." Journal Of The Acoustical Society Of Korea 33, no. 4 (2014): 255. http://dx.doi.org/10.7776/ask.2014.33.4.255.

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Włodarska, Dorota, Andrzej Klepka, Wieslaw Jerzy Staszewski, and Tadeusz Uhl. "Comparative Study of Instantaneous Frequency Extraction in Nonlinear Acoustics Used for Structural Damage Detection." Key Engineering Materials 588 (October 2013): 33–42. http://dx.doi.org/10.4028/www.scientific.net/kem.588.33.

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Nonlinear acoustics deals with various nonlinear effects that occur in ultrasonic wave propagation. The method is suitable for material characterisation, as it uses different nonlinear phenomena associated with material imperfections. The method has been used for detecting nonlinearities in cracked solids by: measuring distortions of acoustic signals, estimating resonance frequency shifts or assessing nonlinear vibro-acosutic modulations. The latter is the most widely used non-classical approach to probe material nonlinearities. The method involves vibro-acoustic interactions of ultrasonic wave and modal vibration in damaged specimens. Modulation intensity that strongly relates to damage severity - is usually assessed in the frequency domain and often leads to confusing results when large modulations are involved. The paper investigates the time domain analysis of vibro-acoustic modulated signals. Several methods for instantaneous frequency calculation used to assess the intensity of modulation - are compared. Simulated and experimental data are used in these investigations.

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Cao, Jun, Fenghua Qi, Senlin Yan, and Lifa Zhang. "Design of highly-efficient acoustic waveguide couplers using impedance-tunable transformation acoustics." International Journal of Modern Physics B 34, no. 32 (November 5, 2020): 2050250. http://dx.doi.org/10.1142/s0217979220502501.

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In this paper, the theory of impedance-tunable transformation acoustics in the geometric-acoustics limit is proposed to design efficient two-dimensional acoustic waveguide couplers. By choosing suitable impedance functions in the original space, impedance matching between the transformation medium and the background medium becomes possible, and the reflection at the boundary is reduced. The theory can be used to enable efficient acoustic coupling between waveguides of different sizes and different embedded media. By selecting an appropriate impedance function and a tunable acoustic refractive index, the transformed medium in the coupler can become a simplified parameter medium, for which the bulk modulus is a constant. This makes the experiment substantially easier. The problem of a reduced coupling-efficiency at low frequencies (a deviation from the geometric acoustic approximation) can be mitigated by selecting a large acoustic refractive index. Our two-dimensional numerical simulations indicate that this theoretical design works very well. The method can be extended to other transformation acoustic designs including three-dimensional cases.

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Muir, Thomas G., David G. Browning, and Kenneth G. Foote. "Nonlinear acoustics and the Acoustical Society of America." Journal of the Acoustical Society of America 138, no. 3 (September 2015): 1842. http://dx.doi.org/10.1121/1.4933864.

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Pazini Brandao, Mauricio. "Nonlinear acoustics—Coupling between hydrodynamic and acoustic pressure fields." Journal of the Acoustical Society of America 112, no. 5 (November 2002): 2215. http://dx.doi.org/10.1121/1.4778740.

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WALSH, TIMOTHY, and MONICA TORRES. "FINITE ELEMENT METHODS FOR NONLINEAR ACOUSTICS IN FLUIDS." Journal of Computational Acoustics 15, no. 03 (September 2007): 353–75. http://dx.doi.org/10.1142/s0218396x0700338x.

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In this paper, weak formulations and finite element discretizations of the governing partial differential equations of three-dimensional nonlinear acoustics in absorbing fluids are presented. The fluid equations are considered in an Eulerian framework, rather than a displacement framework, since in the latter case the corresponding finite element formulations suffer from spurious modes and numerical instabilities. When taken with the governing partial differential equations of a solid body and the continuity conditions, a coupled formulation is derived. The change in solid/fluid interface conditions when going from a linear acoustic fluid to a nonlinear acoustic fluid is demonstrated. Finite element discretizations of the coupled problem are then derived, and verification examples are presented that demonstrate the correctness of the implementations. We demonstrate that the time step size necessary to resolve the wave decreases as steepening occurs. Finally, simulation results are presented on a resonating acoustic cavity, and a coupled elastic/acoustic system consisting of a fluid-filled spherical tank.

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Molevich, Nonna E., Anatoly I. Klimov, and Vladimir G. Makaryan. "Influence of Thermodynamic Nonequilibrium on the Acoustic Properties of Gases." International Journal of Aeroacoustics 4, no. 3 (July 2005): 373–83. http://dx.doi.org/10.1260/1475472054771411.

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This paper is a brief review of results of experimental and theoretical studies in the field of acoustics of nonequilibrium gas-plasma media. New acoustical properties of nonequilibrium media caused by the change in sign of the second viscosity and the dispersion coefficients are considered. Such media are acoustically active. Conditions are discussed for generating new nonlinear acoustical structures.

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Abbasov, Iftikhar B. "A research and modeling of wave processes at the scattering of nonlinear acoustic waves on cylindrical bodies." International research journal of engineering, IT & scientific research 5, no. 5 (September 30, 2019): 32–44. http://dx.doi.org/10.21744/irjeis.v5n5.779.

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The article is devoted to the study of the scattering of nonlinear acoustic waves on cylindrical bodies. There was made a review of publications on the scattering of acoustic waves by inhomogeneities of the medium in the form of cylindrical bodies and shells. There were noted features of the small parameter method application in nonlinear acoustics. A three-dimensional model of the geometry of the problem in cylindrical coordinates was presented, nonlinear wave processes occurring between the falling plane and scattered cylindrical waves were described. The inhomogeneous wave equation is solved by the method of successive approximations of series expansion in a small parameter. An asymptotic expression for the acoustic pressure of a difference-frequency wave was obtained. A program for calculating scattering diagrams has been developed, and an algorithm for its operation is given. The acoustic pressure scattering diagram of a differential frequency wave on a rigid cylinder and its three-dimensional model are presented. The radius of convergence of the used method of expansion in a small parameter is determined.

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Ilyahinsky, A. V., and V. M. Rodyushkin. "About the nonlinear acoustic parameter during deformation of AMG61 alloy." PNRPU Mechanics Bulletin, no. 3 (December 15, 2020): 41–47. http://dx.doi.org/10.15593/perm.mech/2020.3.05.

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Various acoustic effects are used in the study of deformation processes. Acoustic emission is most often mentioned in such studies, and the effects due to nonlinear properties of a deformable metal are the subject of the present work. These properties of real solids lead to nonlinear acoustic effects of the interaction elastic waves forbidden by the theory of elasticity of a homogeneous isotropic body. The work solves the problem of using the principles of nonlinear acoustics in studying the deformation of AMg61 alloy samples. A surface elastic wave is used to control the alloy condition. The process of the elastic wave propagation in the deformed AMg61 alloy due to nonlinear effects is accompanied by generating the double frequency, both of the longitudinal component of the wave and the shear one, the latter is forbidden by equations of the classical elasticity theory. Excitation and reception in the samples was carried out by piezoelectric converters (PES). A wedge converter with a resonance frequency of 1MHz was used to excite the surfactant. The passing surfactant was recorded by a wedge converter with a resonance frequency of 2 MHz. We justified the control technique of the nonlinear acoustic parameter with respect to amplitudes of the first and second harmonics measured during the whole deformation process. An experimental device has been developed to control the nonlinear acoustic parameter in the process of changing the structural state of the sample metal. The pilot study results of the nonlinear acoustic parameter under Amg61 alloy deformation are given. It is shown that the nonlinear acoustic parameter, as well as the acoustic emission activity, is sensitive to changing mechanisms of the defective structure evolution. The non-linearity jump formation during deformation of alloy AMg61 is recorded, which may indicate adjustment of the metal structure. The presented data demonstrate the increase of acoustic nonlinearity in metal at various deformation stages, both at early stages of elastoplastic deformation and at pre-destruction stage, which can be used as the prognostic criterion.

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Lauterborn, Werner, Thomas Kurz, and Ulrich Parlitz. "Experimental Nonlinear Physics." International Journal of Bifurcation and Chaos 07, no. 09 (September 1997): 2003–33. http://dx.doi.org/10.1142/s0218127497001539.

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The review gives and account of the historical development, the current state and possible future developments of experimental nonlinear physics, with emphasis on acoustics, hydrodynamics and optics. The concepts of nonlinear time-series analysis which are the basis of the analysis of experimental outcomes from nonlinear systems are explained and recent developments pertaining to such different fields as modeling, prediction, nonlinear noise reduction, detecting determinism, synchronization, and spatio-temporal time series are surveyed. An overview is given of experiments on acoustic cavitation, a field rich of nonlinear phenomena such as nonlinear oscillations, chaotic dynamics and structure formation, and one of the first physical systems to exhibit period-doubling and chaos in experiment.

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Broda, Dariusz, Andrzej Klepka, Wieslaw Jerzy Staszewski, and Fabrizio Scarpa. "Nonlinear Acoustics in Non-Destructive Testing - From Theory to Experimental Application." Key Engineering Materials 588 (October 2013): 192–201. http://dx.doi.org/10.4028/www.scientific.net/kem.588.192.

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A growing interest in non-destructive testing methods based on nonlinear acoustics have been observed for the last ten fifteen years. The majority of methods in this area take their origin from the observation that fatigue damaged materials often behave like mesoscopic nonlinear materials (e.g. rocks) in which nonlinear phenomena have been observed for years. The most important phenomena include: higher harmonics generation, vibro-acoustic wave modulations, amplitude dependent resonance frequency shift and slow dynamic effects. All these phenomena result mainly from elastic wave interactions with contact-type defects. There is enough experimental evidence in the literature showing that these nonlinear effects are much more distinct in damaged materials than in intact ones. Despite the fact that many experimental techniques - based on nonlinear acoustic phenomena - have been developed for the last ten years, the physical mechanism of elastic wave interaction with damage materials still not clear. The main reason is the variety of possible nonlinear mechanisms involved. This includes: nonlinear elasticity and dissipation, contact acoustic nonlinearity based on herztian and rough surfaces contact theories and other effects such us adhesion, friction and thermoelasticity. This paper provides a short summary of various theoretical developments and examples of applications to damage detection in different materials.

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AGUILERA, R. CARREÑO, WEN YU, J. C. TOVAR RODRÍGUEZ, M. ANTONIO ACEVEDO MOSQUEDA, and S. L. GOMEZ CORONEL. "A NONLINEAR ESTIMATION ACOUSTIC TRANSDUCER BASED ON A VARIABLE STRUCTURE CONTROL LAW." Fractals 25, no. 02 (April 2017): 1750018. http://dx.doi.org/10.1142/s0218348x17500189.

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Electronic sensor devices in geophysical processes are required to measure and automate different tasks. Throughout history, people have created multiple type devices, but acoustics have an important application such as the content form description in deep wells, watersheds, lakes, caves, among others. The acoustic signal is capable of reflecting where other types of signals cannot operate, either by drawbacks or where fluid is displaced. A mathematical model is presented in this paper described in state space as a basic acoustic sensor description. The objective is to adjust the parameters allowing the acoustic device to describe a signal in its trajectory, representing in geophysical manner the cavity form. Therefore, the control is performed on the response of the acoustic sensor model, adjusted with a parameter estimation process. The simulation results counts convergence between the reference and identified signals.

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Larraza, Andrés, and Bruce Denardo. "Acoustics 1996: Acoustic waveguides as tools in fundamental nonlinear physics." Journal of the Acoustical Society of America 101, no. 1 (January 1997): 27–28. http://dx.doi.org/10.1121/1.419505.

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Gurbatov, S. N., and O. V. Rudenko. "On the Inverse Problems of Nonlinear Acoustics and Acoustic Turbulence." Radiophysics and Quantum Electronics 58, no. 7 (December 2015): 463–76. http://dx.doi.org/10.1007/s11141-015-9620-3.

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Vanhille, Christian, Cristian Pantea, and Dipen N. Sinha. "Acoustic Characterization of Fluorinert FC-43 Liquid with Helium Gas Bubbles: Numerical Experiments." Shock and Vibration 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/2518168.

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In this work, we define the acoustic characteristics of a biphasic fluid consisting of static helium gas bubbles in liquid Fluorinert FC-43 and study the propagation of ultrasound of finite amplitudes in this medium. Very low sound speed and high sound attenuation are found, in addition to a particularly high acoustic nonlinear parameter. This result suggests the possibility of using this medium as a nonlinear enhancer in various applications. In particular, parametric generation of low ultrasonic frequencies is studied in a resonator cavity as a function of driving pressure showing high conversion efficiency. This work suggests that this medium could be used for applications such as parametric arrays, nondestructive testing, diagnostic medicine, sonochemistry, underwater acoustics, and ultrasonic imaging and to boost the shock formation in fluids.

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REEDER, D. BENJAMIN, LINUS Y. S. CHIU, and CHI-FANG CHEN. "EXPERIMENTAL EVIDENCE OF HORIZONTAL REFRACTION BY NONLINEAR INTERNAL WAVES OF ELEVATION IN SHALLOW WATER IN THE SOUTH CHINA SEA: 3D VERSUS Nx2D ACOUSTIC PROPAGATION MODELING." Journal of Computational Acoustics 18, no. 03 (September 2010): 267–78. http://dx.doi.org/10.1142/s0218396x10004176.

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A joint Taiwanese-U.S. field experiment was conducted in the South China Sea (SCS), entitled the South China Sea Oceanic Processes Experiment (Taiwan)/Non-Linear Internal Waves Initiative (US) (SCOPE/NLIWI), the ocean acoustics portion of which occurred during April 12–22, 2007. The acoustics objective was to quantify the temporal and spatial variability in acoustic propagation characteristics on the continental shelf in the presence of locally-generated and trans-basin nonlinear internal waves (NLIW). Broadband (400 Hz center frequency) m-sequence signals transmitted nearly continuously by a source moored near the seabed were received by vertical line arrays at 3 and 6 km range. The acoustic transect was oriented approximately parallel to the wave fronts of the shoaling trans-basin NLIW's which had crossed the deep basin from their origin in the Luzon Strait. The acoustic propagation variability due to strong vertical and horizontal refraction induced by the very large NLIW's creates an extremely complex acoustic field as a function of time and space. Experimental data and numerical acoustic propagation modeling results are presented to (1) examine and estimate the contribution of internal wave induced horizontal refraction to the received acoustic field; and (2) to quantify the range of propagation angles relative to the internal wave fronts within which strong horizontal refraction occurs and 3D propagation models are required to accurately predict the range- and depth-dependent acoustic propagation.

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Xu, Weikai, Yingchun Tang, Meng Zhang, Wuchao Qi, and Wei Wang. "Arbitrary shaped acoustic omnidirectional absorber based on transformation theory." International Journal of Modern Physics B 34, no. 11 (April 30, 2020): 2050111. http://dx.doi.org/10.1142/s0217979220501118.

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In this study, an arbitrary shaped acoustic omnidirectional absorber (AOA) is achieved for absorbing incoming acoustic/elastic waves in the ambient environment. Using the transformation acoustics theory, we present a theoretical framework for two-dimensional acoustic path guidance around arbitrary shapes for which the material parameters in the transformed space can be obtained analytically. Results indicate that the transformed space is distorted rather than compressed; numerical simulations confirm that these absorbers exhibit a remarkably large absorption and that the proposed method can control acoustic absorption for arbitrary geometries of interest. This method can potentially be applied to sound absorption and noise control.

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Petrie, Owen D., and Edward J. Brambley. "Nonlinear Acoustics in a Viscothermal Boundary Layer over an Acoustic Lining." AIAA Journal 58, no. 2 (February 2020): 673–86. http://dx.doi.org/10.2514/1.j058180.

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Ostrovsky, Lev A. "Nonlinear Acoustics." Journal of the Acoustical Society of America 105, no. 2 (February 1999): 578. http://dx.doi.org/10.1121/1.426968.

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Beyer, Robert T. "Nonlinear Acoustics." Journal of the Acoustical Society of America 93, no. 4 (April 1993): 2246. http://dx.doi.org/10.1121/1.406661.

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Zabolotskaya, E. A., and M. A. Breazeale. "Nonlinear Acoustics." Journal of the Acoustical Society of America 99, no. 4 (April 1996): 1815. http://dx.doi.org/10.1121/1.415329.

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Beyer, Robert T. "Nonlinear acoustics." Journal of the Acoustical Society of America 89, no. 4B (April 1991): 1855. http://dx.doi.org/10.1121/1.2029260.

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Pantea, Cristian, and Dipen N. Sinha. "Acoustical filters and nonlinear acoustic wave propagation in liquids." Journal of the Acoustical Society of America 129, no. 4 (April 2011): 2678. http://dx.doi.org/10.1121/1.3588978.

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BASKAR, SAMBANDAM, FRANÇOIS COULOUVRAT, and RÉEGIS MARCHIANO. "Nonlinear reflection of grazing acoustic shock waves: unsteady transition from von Neumann to Mach to Snell–Descartes reflections." Journal of Fluid Mechanics 575 (March 2007): 27–55. http://dx.doi.org/10.1017/s0022112006003752.

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We study the reflection of acoustic shock waves grazing at a small angle over a rigid surface. Depending on the incidence angle and the Mach number, the reflection patterns are mainly categorized into two types, namely regular reflection and irregular reflection. In the present work, using the nonlinear KZ equation, this reflection problem is investigated for extremely weak shocks as encountered in acoustics. A critical parameter, defined as the ratio of the sine of the incidence angle and the square root of the acoustic Mach number, is introduced in a natural way. For step shocks, we recover the self-similar (pseudo-steady) nature of the reflection, which is well known from von Neumann's work. Four types of reflection as a function of the critical parameter can be categorized. Thus, we describe the continuous but nonlinear and non-monotonic transition from linear reflection (according to the Snell–Descartes laws) to the weak von-Neumann-type reflection observed for almost perfectly grazing incidence. This last regime is a new, one-shock regime, in contrast with the other, already known, two-shock (regular reflection) or three-shock (von Neumann-type reflection) regimes. Hence, the transition also resolves another paradox on acoustic shock waves addressed by von Neumann in his classical paper. However, step shocks are quite unrealistic in acoustics. Therefore, we investigate the generalization of this transition for N-waves or periodic sawtooth waves, which are more appropriate for acoustics. Our results show an unsteady reflection effect necessarily associated with the energy decay of the incident wave. This effect is the counterpart of step-shock propagation over a concave surface. For a given value of the critical parameter, all the patterns categorized for the step shock may successively appear when the shock is propagating along the surface, starting from weak von-Neumann-type reflection, then gradually turning to von Neumann reflection and finally evolving into nonlinear regular reflection. This last one will asymptotically result in linear regular reflection (Snell–Descartes). The transition back to regular reflection is one of two types, depending on whether a secondary reflected shock is observed. The latter case, here described for the first time, appears to be related to the non-constant state behind the incident shock, which prevents secondary reflection.

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Vakakis, Alexander F. "Passive nonlinear targeted energy transfer." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2127 (July 23, 2018): 20170132. http://dx.doi.org/10.1098/rsta.2017.0132.

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Nonlinearity in dynamics and acoustics may be viewed as scattering of energy across frequencies/wavenumbers. This is in contrast with linear systems when no such scattering exists. Motivated by irreversible large-to-small-scale energy transfers in turbulent flows, passive targeted energy transfers (TET) in mechanical and structural systems incorporating intentional strong nonlinearities are considered. Transient or permanent resonance captures are basic mechanisms for inducing TET in such systems, as well as nonlinear energy scattering across scales caused by strongly nonlinear resonance interactions. Certain theoretical concepts are reviewed, and some TET applications are discussed. Specifically, it is shown that the addition of strongly nonlinear local attachments in an otherwise linear dynamical system may induce energy scattering across scales and ‘redistribution' of input energy from large to small scales in the linear modal space, in similarity to energy cascades that occur in turbulent flows. Such effects may be intentionally induced in the design stage and may lead to improved performance, e.g. it terms of vibration and shock isolation or energy harvesting. In addition, a simple mechanical analogue in the form of a nonlinear planar chain of particles composed of linear stiffness elements but exhibiting strong nonlinearity due to kinematic and geometric effects is discussed, exhibiting similar energy scattering across scales in its acoustics. These results demonstrate the efficacy of intentional utilization of strong nonlinearity in design to induce predictable and controlled intense multi-scale energy transfers in the dynamics and acoustics of a broad class of systems and structures, thus achieving performance objectives that would be not possible in classical linear settings. This article is part of the theme issue ‘Nonlinear energy transfer in dynamical and acoustical systems’.

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Orchini, A., S. J. Illingworth, and M. P. Juniper. "Frequency domain and time domain analysis of thermoacoustic oscillations with wave-based acoustics." Journal of Fluid Mechanics 775 (June 25, 2015): 387–414. http://dx.doi.org/10.1017/jfm.2015.139.

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Many thermoacoustic systems exhibit rich nonlinear behaviour. Recent studies show that this nonlinear dynamics can be well captured by low-order time domain models that couple a level set kinematic model for a laminar flame, the $G$-equation, with a state-space realization of the linearized acoustic equations. However, so far the $G$-equation has been coupled only with straight ducts with uniform mean acoustic properties, which is a simplistic configuration. In this study, we incorporate a wave-based model of the acoustic network, containing area and temperature variations and frequency-dependent boundary conditions. We cast the linear acoustics into state-space form using a different approach from that in the existing literature. We then use this state-space form to investigate the stability of the thermoacoustic system, both in the frequency and time domains, using the flame position as a control parameter. We observe frequency-locked, quasiperiodic and chaotic oscillations. We identify the location of Neimark–Sacker bifurcations with Floquet theory. We also find the Ruelle–Takens–Newhouse route to chaos with nonlinear time series analysis techniques. We highlight important differences between the nonlinear response predicted by the frequency domain and the time domain methods. This reveals deficiencies with the frequency domain technique, which is commonly used in academic and industrial studies of thermoacoustic systems. We then demonstrate a more accurate approach based on continuation analysis applied to time domain techniques.

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Boluriaan, Said, and Philip J. Morris. "Acoustic Streaming: From Rayleigh to Today." International Journal of Aeroacoustics 2, no. 3 (July 2003): 255–92. http://dx.doi.org/10.1260/147547203322986142.

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This paper reviews the current state of knowledge of several classes of acoustic streaming. Acoustic streaming is classified based on the different mechanisms by which it is generated. For each category, the main achievements in terms of analysis, experimental work, and numerical simulation are described. An order of magnitude analysis, applicable to all types of acoustic streaming, is also given. This provides an additional means to classify acoustic streaming as either slow or fast, depending on the amplitude of the primary driving mechanism. The significant lack of understanding in the general area of fast streaming is noted, and the importance of the use of direct numerical simulations in the study of nonlinear streaming is emphasized. The paper concludes with a summary of the many challenges that are still faced by researchers in this field. The authors are pleased to contribute this paper in honor of Alan Powell's significant contributions to acoustics on the occasion of his eightieth birthday.

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Zhu, Haodong, Peiran Zhang, Zhanwei Zhong, Jianping Xia, Joseph Rich, John Mai, Xingyu Su, et al. "Acoustohydrodynamic tweezers via spatial arrangement of streaming vortices." Science Advances 7, no. 2 (January 2021): eabc7885. http://dx.doi.org/10.1126/sciadv.abc7885.

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Acoustics-based tweezers provide a unique toolset for contactless, label-free, and precise manipulation of bioparticles and bioanalytes. Most acoustic tweezers rely on acoustic radiation forces; however, the accompanying acoustic streaming often generates unpredictable effects due to its nonlinear nature and high sensitivity to the three-dimensional boundary conditions. Here, we demonstrate acoustohydrodynamic tweezers, which generate stable, symmetric pairs of vortices to create hydrodynamic traps for object manipulation. These stable vortices enable predictable control of a flow field, which translates into controlled motion of droplets or particles on the operating surface. We built a programmable droplet-handling platform to demonstrate the basic functions of planar-omnidirectional droplet transport, merging droplets, and in situ mixing via a sequential cascade of biochemical reactions. Our acoustohydrodynamic tweezers enables improved control of acoustic streaming and demonstrates a previously unidentified method for contact-free manipulation of bioanalytes and digitalized liquid handling based on a compact and scalable functional unit.

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Rolt, Kenneth D. "Time domain acoustic absorption: A unified model for linear and nonlinear acoustics." Journal of the Acoustical Society of America 95, no. 5 (May 1994): 2854–55. http://dx.doi.org/10.1121/1.409519.

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Lee. "Partitioned Block Frequency Domain Adaptive Filtering Algorithm for Nonlinear Acoustic Echo Cancellation." Journal of the Acoustical Society of Korea 34, no. 3 (2015): 177. http://dx.doi.org/10.7776/ask.2015.34.3.177.

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Klepka, Andrzej, Wieslaw Jerzy Staszewski, Dario di Maio, Fabrizio Scarpa, Kong Fah Tee, and Tadeusz Uhl. "Sensor Location Analysis in Nonlinear Acoustics Used for Damage Detection in Composite Chiral Sandwich Panels." Advances in Science and Technology 83 (September 2012): 223–31. http://dx.doi.org/10.4028/www.scientific.net/ast.83.223.

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This paper demonstrates damage detection in a smart sandwich panel with integrated piezoceramic transducers. The panel is built from a chiral honeycomb and two composite skins. A low-profile, surface-bonded piezoceramic transducer is used for high-frequency ultrasonic excitation. Low-frequency excitation is performed using a piezoceramic stack actuator. Ultrasonic sensing is performed using laser vibrometry. Nonlinear acoustics is applied for damage detection. The study is focused on sensor location analysis with respect to vibro-acoustic wave modulations. The paper demonstrates that when structure is damaged, the high-frequency “weak” ultrasonic wave is modulated by the low-frequency “strong” vibration wave. As a result frequency sidebands can be observed around the main acoustic harmonic in the spectrum of the ultrasonic signal. However, intensity of modulation strongly depends on sensor location.

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Kaltenbacher, Barbara, and Vanja Nikolić. "The Jordan–Moore–Gibson–Thompson Equation: Well-posedness with quadratic gradient nonlinearity and singular limit for vanishing relaxation time." Mathematical Models and Methods in Applied Sciences 29, no. 13 (December 2, 2019): 2523–56. http://dx.doi.org/10.1142/s0218202519500532.

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In this paper, we consider the Jordan–Moore–Gibson–Thompson equation, a third-order in time wave equation describing the nonlinear propagation of sound that avoids the infinite signal speed paradox of classical second-order in time strongly damped models of nonlinear acoustics, such as the Westervelt and the Kuznetsov equation. We show well-posedness in an acoustic velocity potential formulation with and without gradient nonlinearity, corresponding to the Kuznetsov and the Westervelt nonlinearities, respectively. Moreover, we consider the limit as the parameter of the third-order time derivative that plays the role of a relaxation time tends to zero, which again leads to the classical Kuznetsov and Westervelt models. To this end, we establish appropriate energy estimates for the linearized equations and employ fixed-point arguments for well-posedness of the nonlinear equations. The theoretical results are illustrated by numerical experiments.

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Sapozhnikov, Oleg A. "Nonlinear Acoustics Today." Acoustics Today 15, no. 3 (2019): 55. http://dx.doi.org/10.1121/at.2019.15.3.55.

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Mussel, Matan, and Matthias F. Schneider. "It sounds like an action potential: unification of electrical, chemical and mechanical aspects of acoustic pulses in lipids." Journal of The Royal Society Interface 16, no. 151 (February 2019): 20180743. http://dx.doi.org/10.1098/rsif.2018.0743.

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In an ongoing debate on the physical nature of the action potential (AP), one group adheres to the electrical model of Hodgkin and Huxley, while the other describes the AP as a nonlinear acoustic pulse propagating within an interface near a transition. However, despite remarkable similarities, acoustics remains a non-intuitive mechanism for APs for the following reason. While acoustic pulses are typically associated with the propagation of density, pressure and temperature variation, APs are most commonly measured electrically. Here, we show that this discrepancy is lifted upon considering the electrical and chemical aspects of the interface, in addition to its mechanical properties. Specifically, we demonstrate how electrical and pH aspects of acoustic pulses emerge from an idealized description of the lipid interface, which is based on classical physical principles and contains no fit parameters. The pulses that emerge from the model show similarities to APs not only in qualitative shape and scales (time, velocity and voltage), but also demonstrate saturation of amplitude and annihilation upon collision.

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TABHANE, PRIYANKA V., OMPRAKASH P. CHIMANKAR, and VILAS A. TABHANE. "STUDY OF THERMODYNAMICAL PROPERTIES OF POLYVINYL ACETATE IN TETRAHYDROFURAN." Modern Physics Letters B 26, no. 27 (September 24, 2012): 1250180. http://dx.doi.org/10.1142/s0217984912501801.

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The propagation of ultrasonic waves and the measurement of their velocity in solutions form an important tool for the evaluation of various acoustical and thermodynamical parameters which give an insight into the nature of miscibility and molecular interactions in polymer solutions. In the present study, the ultrasonic velocity, density, viscosity measurements have been made in 0.1 M solution using pulse echo overlap technique at 293 K at the different concentrations of polyvinyl acetate in tetrahydrofuran. Thermo-acoustical parameters viz., adiabatic compressibility, molar sound velocity, molar compressibility, expansion coefficient, acoustic impedance, van der Waals' constant and internal pressure have been computed from the experimental data. The nature of polymer/solvent interaction and the effect of concentration on the molecular interaction are studied. The nonlinear variations of polyvinyl acetate in tetrahydrofuran have been studied. The variation of ultrasonic velocity and other thermo-acoustical parameters shows nonlinear increase or decrease with molar concentration which suggest semi-compatibility of the polymer in the given solvent.

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Lu, Zhiqu. "A long‐term field soil survey by acoustic techniques: Part II. Nonlinear acoustics." Journal of the Acoustical Society of America 121, no. 5 (May 2007): 3164. http://dx.doi.org/10.1121/1.4782249.

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Khokhlova, Vera A., Mikhail V. Averianov, Robin O. Cleveland, and Philippe Blanc‐Benon. "Parabolic approximation versus geometrical acoustics for describing nonlinear acoustic waves in inhomogeneous media." Journal of the Acoustical Society of America 117, no. 4 (April 2005): 2595. http://dx.doi.org/10.1121/1.4777442.

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Klepka, A., WJ Staszewski, RB Jenal, M. Szwedo, J. Iwaniec, and T. Uhl. "Nonlinear acoustics for fatigue crack detection – experimental investigations of vibro-acoustic wave modulations." Structural Health Monitoring: An International Journal 11, no. 2 (July 25, 2011): 197–211. http://dx.doi.org/10.1177/1475921711414236.

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Cates, A. T. "Diffracting nonlinear acoustic beams in 3 + 1 dimensions with applications to oceanic acoustics." Physica D: Nonlinear Phenomena 44, no. 3 (September 1990): 303–12. http://dx.doi.org/10.1016/0167-2789(90)90151-e.

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Ермолаев, Валерий, Valeriy Ermolaev, Юрий Кропотов, Yuriy Kropotov, Наталья Холкина, and Natalya Kholkina. "FUNCTIONAL DIFFERENTIAL AND DIFFERENTIAL MODELS OF SYSTEMS WITH ACOUSTICAL FEEDBACK." Bulletin of Bryansk state technical university 2019, no. 4 (May 14, 2019): 60–67. http://dx.doi.org/10.30987/article_5cb58f516d2bd2.01655840.

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The paper reports the investigations of the functional differential and differential models of system with acoustic feedback. The aim of the work is a for-mation, analysis and identification of linear and nonlinear functional differential models of echo, reverberation and acoustic feedback; the analysis of model sensitivity, the analysis of stability of telecommunication systems with the acoustic feedback. There is presented a mechanism of an acoustic feedback mechanism formation. At the analysis of sound propagation in closed rooms with the use of the geometric acoustics method there is obtained a nucleus equation which is approximated by nonnegative functions taking into account a model of reverberation and a model of multiple reflections. The considered procedure of echo formation and reverberation is an element of the feedback model common for warning systems and technological communication. There is investigated a model of acoustic systems with delayed feedback. A diagram of the kernel of a functional differential equation describing a system with feedback is shown. The models of systems with acoustic feedback presented in this work ensure the approximation to reality at that, an account of possibilities of the emergence in channels of non-linear distortion sound propagation are considered to be the next problem.

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CHIU, YUNG-SHENG, YUAN-YING CHANG, LI-WEN HSIEH, MEI-CHUN YUAN, and CHI-FANG CHEN. "THREE-DIMENSIONAL ACOUSTICS EFFECTS IN THE ASIAEX SCS EXPERIMENT." Journal of Computational Acoustics 17, no. 01 (March 2009): 11–27. http://dx.doi.org/10.1142/s0218396x09003835.

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A three-dimensional (3D) ocean environment is assimilated with measured ocean data in the ASIAEX SCS (Asian Seas International Acoustics EXperiment, South China Sea) experiment. The experiment site is characterized as an active internal wave propagation region along the Northwestern shelf break of the South China Sea. Three-dimensional acoustics effects in the area are studied using FOR3DW, a wide-angle version of the parabolic equation code FOR3D (a Finite difference solution, an Ordinary differential equation, and Rational function approximations for solving 3D problems), and MOS3DPEF (MOdal Spectrum analysis based on 3D PE Field). The TL comparison between Nx2D and 3D calculations are shown to demonstrate the 3D effects. Variations in topography of the shelf break and in the water column due to the internal waves cause the 3D effects in the acoustic field. The intercomparison of the importance of bottom steering 3D effects and nonlinear internal wave refraction 3D effects is therefore proposed to realize which possesses the major part of the 3D effects. Also, 3D modal analysis results show that the nonlinear internal wave front causes severe horizontal refraction for higher modes.

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Dobrucki, Andrzej. "In Memoriam. Zygmunt Grzegorz Wąsowicz Ph.D." Archives of Acoustics 39, no. 1 (March 1, 2015): 151. http://dx.doi.org/10.2478/aoa-2014-0016.

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Abstract Zygmunt G. Wąsowicz, PhD emeritus of the Chair of Acoustics and Multimedia, Wrocław University of Technology, passed away on the 8th of January 2014. His whole professional career was associated with the acoustics. Dr. Z. Wąsowicz was born in Nowy Sącz in 1931. In 1956 he graduated from the Faculty of Telecommunications at the Wrocław University of Technology and started to work there in the same year. In 1966 he obtained the PhD title, under supervision of Professor Z. Żyszkowski, for the dissertation concerning the subjective criteria of nonlinear distortions in loudspeakers. His main interests of activity were room acoustics as well as subjective assessment of sound quality. He worked out the subjective method of loudspeaker evaluation for Polish Loudspeaker Company “Tonsil” – this method was based on so-called “the live apparent sound”. He worked also on computer methods of acoustical field modeling in rooms. The works mentioned above were pioneer and modern in Poland. He participated as an acoustician, in various designers groups at for example auditory halls of Faculty of Electronics. Dr. Wąsowicz was the outstanding academical teacher whom students liked very much. He was also a member of Polish Acoustical Society and worked for the Main Board as well as the Wrocław Division of this society. In periods 1979–1983 and 1994–1996 he was the vice-dean of Faculty of Electronics. He received many awards, for example Golden Cross of Merit, Knight’s Cross of the Order of Polonia Restituta, Medal of the National Education Commission and many awards from the Governors of Wrocław University of Technology and Institute of Telecommunications and Acoustics. In 1996 he was retired and beside of this he stayed in contact with Faculty of Electronics for many years. Wrocław acoustical community mourns the loss of Dr. Z. Wąsowicz.

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Liu, FeiFei, ShuJie Jiang, Gang Chen, and Yueming Li. "Numerical Investigation on Vortex-Structure Interaction Generating Aerodynamic Noises for Rod-Airfoil Models." Mathematical Problems in Engineering 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/3704324.

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In past several decades, vortex-structure interaction generated aerodynamic noise became one of the main concerns in aircraft design. In order to understand the mechanism, the acoustic analogy method combined with the RANS-based nonlinear acoustics solver (NLAS) is investigated. The numerical method is firstly evaluated by the experiment data of the classic rod-airfoil model. Compared with the traditional analogy methods, the RANS/NLAS can capture the nonlinear aerodynamic noise more accurately with lower gird requirements. Then different rod-airfoil configurations were simulated to investigate the aeroacoustic interaction effects. The numerical results are in good agreement with those of the earlier experimental research. It is found that the vortex-shedding crash to the airfoil is the main reason for the noise generation which is dependent on the configurations, distance, and flow conditions.

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Wu, Xuesong. "Asymptotic approach to combustion instability." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363, no. 1830 (April 26, 2005): 1247–59. http://dx.doi.org/10.1098/rsta.2005.1565.

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This paper presents an asymptotic approach to combustion instability in premixed flames under the assumptions of large activation energy and small Mach number. The entire flow consists of four distinct yet fully interactive sub-regions, which accommodate the chemical reaction, heat transport, hydrodynamics and acoustics, respectively. A reduced system was derived to describe the intricate coupling between the flame and acoustics that underlies the combustion instability. The asymptotically reduced system was employed to study the weakly nonlinear interaction between the Darrieus–Landau instability and the longitudinal acoustic mode of the combustion chamber. The general asymptotic formulation includes the influence of enthalpy fluctuation in the oncoming mixture. It is shown that one-dimensional enthalpy fluctuation, through its interaction with flame, produces sound waves, and may cause parametric instability of the flame. The mutual coupling between the sound wave and parametric instability is analysed at the instability thresholds.

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Pieczonka, Łukasz, Andrzej Klepka, Wieslaw Jerzy Staszewski, Tadeusz Uhl, and Francesco Aymerich. "Analysis of Vibro-Acoustic Modulations in Nonlinear Acoustics Used for Impact Damage Detection - Numerical and Experimental Study." Key Engineering Materials 558 (June 2013): 341–48. http://dx.doi.org/10.4028/www.scientific.net/kem.558.341.

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The paper investigates experimentally the effect of low-frequency vibration on nonlinear vibro-acoustic wave modulations applied to the detection of Barely Visible Impact Damage (BVID) in a composite plate. Finite Element (FE) modeling was used in a pretest stage to identify different motion scenarios of delaminated surfaces and relate them to natural frequencies of the damaged plate. In particular the opening-closing and frictional sliding actions of the defected interfaces have been considered. Subsequently, the identified frequencies have been used for low frequency excitation in nonlinear acoustic experiments on a composite plate with impact damage.

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Gendelman, O. V., and A. F. Vakakis. "Introduction to a topical issue ‘nonlinear energy transfer in dynamical and acoustical Systems'." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2127 (July 23, 2018): 20170129. http://dx.doi.org/10.1098/rsta.2017.0129.

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This topical issue is devoted to recent developments in the broader field of energy transfer across scales in nonlinear dynamical and acoustical systems. Nonlinear energy transfers are common in Nature, with perhaps the most famous example being energy cascading from large to small length scales in turbulent flows. Yet nonlinearity has been traditionally perceived either as an unavoidable nuisance or as an unwelcome design restriction in engineering systems. Nowadays, however, this trend is reversing, with nonlinear phenomena being intensely studied in diverse disciplines. Furthermore, strong nonlinearity is now intentionally used and explored in a variety of mechanical and physical settings, such as granular media, acoustic metamaterials, nonlinear energy sinks, essentially nonlinear and nonlocal lattices, vibro-impact oscillators, vibration and shock isolation systems, nanotechnology, biomimetic systems, microelectronics, energy harvesters and in other applications. This topical issue is an attempt to document in a single volume some of these recent research developments, in order to establish a common basis and provide motivation and incentive for further development. The aim is to discuss and compare theoretical and experimental approaches pursued by research groups in different areas, and describe the state of the art of nonlinear energy transfer phenomena in an as broad as possible range of applications of current interest. This article is part of the theme issue ‘Nonlinear energy transfer in dynamical and acoustical systems’.

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Cammarata, M., D. Dutta, Hoon Sohn, P. Rizzo, and Kent A. Harries. "Advanced Ultrasonic Structural Monitoring of Waveguides." Advances in Science and Technology 56 (September 2008): 477–82. http://dx.doi.org/10.4028/www.scientific.net/ast.56.477.

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Ultrasonic Guided Waves (UGWs) are a useful tool in those structural health monitoring applications that can benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes two methods, based on linear and nonlinear acoustics for structural damage detection based on UGWs. The linear method combine the advantages of UGW inspection with the outcomes of the Discrete Wavelet Transform (DWT) that is used for extracting defect-sensitive features that can be combined to perform a multivariate diagnosis of damage. In particular, the DWT is exploited to generate a set of relevant wavelet coefficients to construct a uni-dimensional or multi-dimensional damage index that, in turn is fed to an outlier algorithm to detect anomalous structural states. The nonlinear acoustics method exploits the circumstance that a cracked medium exhibits high acoustic nonlinearity which is manifested as harmonics in the power spectrum of the received signal. Experimental results also indicate that the harmonic components increase non-linearly in magnitude with increasing amplitude of the input signal. The proposed nonlinear technique identifies the presence of cracks by looking at the harmonics and their nonlinear relationship to the input amplitude. The general framework presented in this paper is applied to the detection of fatigue cracks in an I-shaped steel beam. The probing hardware consists of Lead Zirconate Titanate (PZT) materials used for both ultrasound generation and detection at chosen frequency. The effectiveness of the proposed methods for the structural diagnosis of defects that are small compared to the waveguide cross-sectional area is discussed.

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Alekseev, Gennady V., Aleksey Lobanov, and Gleb Grenkin. "Numerical Study of Inverse Problems of Nonscattering Anisotropic Shell Theory." Applied Mechanics and Materials 249-250 (December 2012): 557–62. http://dx.doi.org/10.4028/www.scientific.net/amm.249-250.557.

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The inverse problems are formulated for generalized Helmholtz equation describing propagation of acoustics waves in inhomogeneous anisotropic medium. These problems are connected with constructing nonscattering shells filled with anisotropic fluid. For solving the inverse problems we apply the nonlinear optimization techniques. Based on this approach we formulate the general control problem for the Helmholtz equation under consideration. The control problem consists of minimization of a suitable cost functional depending on the state (acoustic pressure) and unknown functions (controls). The optimality system for the general control problem is derived, the sufficient conditions for data which provide a local stability and uniqueness of control problems under study for concrete tracking-type cost functionals are discussed. The efficient numerical algorithm of solving control problem under study based on Newton's method of solving nonlinear equations and finite element for Helmholtz boundary value problems is proposed.

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Journal articles on the topic 'Nonlinean acoustics'

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