{"title":"Topology-optimized reflection-type pentamode metasurfaces for broadband underwater beam regulation","authors":"Sheng-Dong Zhao , Yue-Sheng Wang , Chuanzeng Zhang , Hao-Wen Dong","doi":"10.1016/j.wavemoti.2025.103515","DOIUrl":"10.1016/j.wavemoti.2025.103515","url":null,"abstract":"<div><div>Pentamode metamaterials (PMs), a type of customizable artificial liquid-like material, consist of intricate solid microstructural units, offering promising applications in manipulating underwater waves. With their excellent acoustic impedance matching properties with water and customizable equivalent parameters, PMs can surpass the narrowband limitations and facilitate the design of broadband acoustic metasurfaces. However, due to a lack of comprehensive research on PM mechanisms, many researchers opt for conventional regular triangle lattices, limiting both structural diversity and the potential for obtaining precise equivalent parameters. In this study, we propose an inverse optimization strategy to design a series of PM units featuring square lattices. Leveraging the generalized acoustic Snell's law and impedance matching properties of PMs, we construct several reflective broadband subwavelength acoustic metasurfaces. These metasurfaces enable various functionalities based on wavefront manipulation, including an acoustic shielding device capable of converting reflected waves into surface waves across a broad frequency spectrum. Additionally, we achieve broadband anomalous reflection, achromatic focusing, and non-diffracting Bessel beams. Notably, all these achromatic functionalities exhibit relative bandwidths exceeding 100%, indicating promising application prospects.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"135 ","pages":"Article 103515"},"PeriodicalIF":2.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-02-10DOI: 10.1016/j.wavemoti.2025.103510
Jian-Yong Wang , Xiao-Yan Tang , Yong Chen
{"title":"Resonant line solitons and localized excitations in a (2+1)-dimensional higher-order dispersive long wave system in shallow water","authors":"Jian-Yong Wang , Xiao-Yan Tang , Yong Chen","doi":"10.1016/j.wavemoti.2025.103510","DOIUrl":"10.1016/j.wavemoti.2025.103510","url":null,"abstract":"<div><div>In this work, we consider a (2+1)-dimensional higher-order dispersive long wave system that models dispersive long gravity waves in shallow water of finite depth. By transforming the variable separation solution into the <span><math><mi>τ</mi></math></span>-function form, we effectively identify resonant line solitons and analyze their asymptotic behavior. Specifically, those resonant solitons include the <span><math><mrow><mo>(</mo><mn>3142</mn><mo>)</mo></mrow></math></span>-type solitons, T-type solitons, and O-type solitons in shallow water. In addition, we introduce two novel types of instanton excitations induced by dromion resonance. The first type is characterized by different growth and decay rates, while the second type exhibits an odd symmetry, described by <span><math><mrow><mi>A</mi><mrow><mo>(</mo><mo>−</mo><mi>x</mi><mo>,</mo><mi>y</mi><mo>,</mo><mo>−</mo><mi>t</mi><mo>)</mo></mrow><mo>=</mo><mo>−</mo><mi>A</mi><mrow><mo>(</mo><mi>x</mi><mo>,</mo><mi>y</mi><mo>,</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span>. These solutions are applicable to other solvable nonlinear systems using the multilinear variable separation approach. It is hoped that the study will be helpful in the analysis of dispersive long gravity waves propagating in two horizontal directions, such as resonant line solitons on fluid surfaces and hydrodynamic instantons.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"135 ","pages":"Article 103510"},"PeriodicalIF":2.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-02-08DOI: 10.1016/j.wavemoti.2025.103509
M. Červenka, M. Bednařík
{"title":"Analytical modeling of evanescent coupling in metasurface absorbers for enhanced low-frequency sound control","authors":"M. Červenka, M. Bednařík","doi":"10.1016/j.wavemoti.2025.103509","DOIUrl":"10.1016/j.wavemoti.2025.103509","url":null,"abstract":"<div><div>This study presents an analytical approach to model evanescent coupling in planar metasurface absorbers, specifically designed for broadband low-frequency sound absorption. While traditional absorbers rely on thick, wavelength-comparable porous materials, metasurface absorbers with deeply sub-wavelength thickness typically achieve low-frequency absorption using arrays of resonators, such as Helmholtz resonators, folded quarter-wavelength resonators, or backed micro-perforated panels. Standard surface-impedance-based models of metasurface absorbers often ignore inter-resonator coupling effects, leading to inaccuracies in frequency response predictions. Our method incorporates evanescent wave interactions between resonators, whether rectangular or circular in cross-section, arranged in regular super-cells that can repeat periodically or with mirror symmetry, which also corresponds to one super-cell placed in a rigid-walled rectangular waveguide (impedance tube). This approach reduces computational complexity significantly compared to finite element simulations, while still enabling accurate predictions of metasurface absorbing performance. Validated through comparison with two numerical finite element models, this analytical method proves effective for optimizing metasurface absorbers for low-frequency sound control. Numerical experiments further illustrate performance degradation from neglecting evanescent coupling or mismatched super-cell periodicity. Implementation MATLAB code is available on <span><span>https://github.com/MilanCervenka/Evanescent</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103509"},"PeriodicalIF":2.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-02-08DOI: 10.1016/j.wavemoti.2025.103508
Emre Kirli , Serpil Cikit
{"title":"A high order accurate hybrid technique for numerical solution of modified equal width equation","authors":"Emre Kirli , Serpil Cikit","doi":"10.1016/j.wavemoti.2025.103508","DOIUrl":"10.1016/j.wavemoti.2025.103508","url":null,"abstract":"<div><div>In this present study, a high-order accurate hybrid technique is developed to establish the approximate solution of Modified Equal Width (MEW) equation which is used to define solitary waves. The spatial integration is based on combining the cubic B-spline and a fourth-order compact finite-difference (FOCFD) scheme , while the temporal integration is carried out by using fourth-order Runge–Kutta (RK4) scheme. In present technique, the new approximation for the spatial second derivative is constructed by the FOCFD scheme in which the spatial second derivatives of unknowns can be written in terms of the unknowns themselves and their first derivatives. Hence, the spatial second derivative reaches the accuracy of order four, while it is represented by the accuracy of order two in the standard cubic B-spline. The stability of the suggested technique is discussed by using the concept of eigenvalue. Three test problems are examined to verify the efficiency and applicability of the suggested technique. The computed results are compared with the other numerical results in previous works. The comparisons reveal that the suggested hybrid technique provides better results with high accuracy and minimum computational effort.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"135 ","pages":"Article 103508"},"PeriodicalIF":2.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-02-08DOI: 10.1016/j.wavemoti.2025.103514
Junzhen Wang , Jianmin Qu
{"title":"Numerical investigations of deep learning-assisted delamination characterization using ultrasonic guided waves","authors":"Junzhen Wang , Jianmin Qu","doi":"10.1016/j.wavemoti.2025.103514","DOIUrl":"10.1016/j.wavemoti.2025.103514","url":null,"abstract":"<div><div>Ultrasonic guided waves have been applied extensively for nondestructively detecting delamination in multilayered structures. However, traditional guided-wave-based nondestructive evaluation (NDE) techniques require highly skilled users to interpret the complex wave field scattered by the delamination. To overcome this challenge, this study proposes an approach that combines a deep-learning (DL) neural network with traditional ultrasonic NDE techniques. The NDE technique used here is based on guided waves generated and received in a transmitter-receiver configuration. A 2D finite element analysis (FEA) model is constructed to simulate the guided wave interactions with a delamination between two metallic layers, which yields both the training and testing data. The tailored DL neural network is a convolutional neural network (CNN) combined with bi-directional long short-term memory (BiLSTM). This hybrid neural network is trained by a set of pulse-echo or pitch-catch time-domain data. Once trained, the DL neural network predicts the location of delamination using the recorded pulse-echo time-domain signals as input, and the length of delamination using the recoded pitch-catch time-domain as input. This process of nondestructively characterizing the location and size of delamination can be carried out automatically without the need to analyze the complex wave fields in the ultrasonic tests. The predicted results on both within-range and out-of-range unseen data demonstrate that the proposed technique has tremendous potential for characterizing delamination in practical NDE and structural health monitoring (SHM) applications.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103514"},"PeriodicalIF":2.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Solitons, breathers and rogue waves of the Yajima–Oikawa-Newell long wave–short wave system","authors":"Marcos Caso-Huerta , Bao-Feng Feng , Sara Lombardo , Ken-ichi Maruno , Matteo Sommacal","doi":"10.1016/j.wavemoti.2025.103511","DOIUrl":"10.1016/j.wavemoti.2025.103511","url":null,"abstract":"<div><div>In this paper, we consider the recently-introduced Yajima–Oikawa–Newell (YON) system describing the nonlinear resonant interaction between a long wave and a short wave. It extends and generalises the Yajima–Oikawa (YO) and the Newell (N) systems, which can be obtained from the YON system for special choices of the two non-rescalable, arbitrary parameters that it features. Remarkably, for any choice of these latter constants, the YON system is integrable, in the sense of possessing a Lax pair. New families of solutions, including the bright and dark multi-solitons, as well as the breathers and the higher-order rogue waves are systematically derived by means of the <span><math><mi>τ</mi></math></span>-function reduction technique for the two-component KP and the KP-Toda hierarchies. In particular, we show that the condition that the wave parameters have to satisfy for the rogue wave solution to exist coincides with the prediction based on the stability spectra for base-band instability of the plane wave solutions. Several examples from each family of solutions are given in closed form, along with a discussion of their main properties and behaviours.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103511"},"PeriodicalIF":2.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-02-04DOI: 10.1016/j.wavemoti.2025.103507
Carmine Di Nucci , Kamil Urbanowicz , Simone Michele , Daniele Celli , Davide Pasquali , Marcello Di Risio
{"title":"On water hammer waves","authors":"Carmine Di Nucci , Kamil Urbanowicz , Simone Michele , Daniele Celli , Davide Pasquali , Marcello Di Risio","doi":"10.1016/j.wavemoti.2025.103507","DOIUrl":"10.1016/j.wavemoti.2025.103507","url":null,"abstract":"<div><div>Water hammer waves, i.e., low-frequency, low-Mach number propagation of finite-amplitude pressure waves in pipe flow, are investigated by means of the wave equation proposed in Di Nucci et al., 2024a, 2024b. The wave equation, resembling a linear damped wave equation, comes from the turbulent-viscosity model based on the quasi-incompressible Reynolds Averaged Navier–Stokes equations. Changes in temperature due to entropy production are neglected, and adiabatic conditions are imposed. Additional insights on the assumptions used to derive the wave equation are also provided. Focusing on the one-dimensional propagation of pressure waves in liquid-filled pipes (without cavitation), analytical solution of the wave equation is tested against experimental data available from the literature. The impact of the simplifying assumptions on the quantitative outcomes appears to be small; therefore a good level of accuracy in replicating water hammer wave characteristics (including damping, smoothing, and maximum pressure peak) is achieved. Results show that the Reynolds number has minimal influence on water hammer wave propagation, i.e., the vorticity field has no remarkable effect on flow behavior. Deeper attention is given to entropy production, and to the role played by the dimensionless number which is identified as predominant in water hammer wave propagation. Damping properties are also determined.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103507"},"PeriodicalIF":2.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143332279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-01-31DOI: 10.1016/j.wavemoti.2025.103505
Shuang Zhao, Hui Wang, Yunhu Wang
{"title":"Quasiperiodic-to-soliton conversions and their mechanisms of the (3+1)-dimensional generalized Kadomtsev–Petviashvili equation","authors":"Shuang Zhao, Hui Wang, Yunhu Wang","doi":"10.1016/j.wavemoti.2025.103505","DOIUrl":"10.1016/j.wavemoti.2025.103505","url":null,"abstract":"<div><div>This paper systematically investigates the (3+1)-dimensional generalized Kadomtsev–Petviashvili equation, which is widely used to describe various nonlinear phenomena in fluid dynamics and plasma physics. The soliton solutions and multi-periodic wave solutions of this equation are constructed using the Hirota bilinear method and the Riemann theta function. The investigation reveals that the one-periodic waves correspond to the renowned one-dimensional surface cnoidal waves, while the two-periodic waves represent a direct extension of the one-periodic waves. Furthermore, the asymptotic properties of the solutions and the transform relationships between quasiperiodic wave solutions and soliton solutions are analyzed. It is discovered that the quasiperiodic wave solutions can degenerate into soliton solutions under a limiting condition.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103505"},"PeriodicalIF":2.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-01-29DOI: 10.1016/j.wavemoti.2025.103500
Wei Ouyang, Xingchen Shi, Bingkai Han, Weijian Mao
{"title":"Viscoacoustic Gaussian beam inverse scattering imaging method by asymptotic estimation of the single-scattering Hessian operator","authors":"Wei Ouyang, Xingchen Shi, Bingkai Han, Weijian Mao","doi":"10.1016/j.wavemoti.2025.103500","DOIUrl":"10.1016/j.wavemoti.2025.103500","url":null,"abstract":"<div><div>Attenuation compensation has been introduced in the field of linearized inverse scattering problems for the restoration of geological structures and material properties within viscoacoustic media, which are characterized by P-wave velocity and the quality factor <span><math><mi>Q</mi></math></span>. It relies on the solution of a true-amplitude asymptotic inversion, incorporating a single-scattering propagation operator. Nonetheless, traditional mathematical treatments of asymptotic inversion often overlook the viscous properties of the medium. In this study, we investigate the application of the Gaussian-beam depth migration technique, which takes into account multiple wave arrivals, to address the complexities associated with true-amplitude viscoacoustic inverse scattering. This method presents a precise and adaptable alternative to conventional single-arrival ray-based migration techniques. Our focus is on viscoacoustic inversion imaging using the single-scattering Hessian operator, deemed essential for full waveform inversion. In this situation, we demonstrate how to derive an appropriate weighting filter that allows the dominant part of the weighted Hessian operator to effectively approximate the identity operator. As a result, we develop a new form of pseudoinverse operator linked to the Born modeling operator for a single-beam-center slowness component of the wavefield. This operator facilitates the implementation of viscoacoustic Gaussian beam prestack depth migration on common-shot gathers, thereby offering a robust solution for imaging complex structures where single-arrival ray-based approaches are insufficient. Numerical results derived from the analysis of 2D realistic synthetic datasets substantiate the effectiveness of the proposed methodology. This work not only advances the understanding of viscoacoustic imaging techniques but also significantly enhances their practical application in challenging geological scenarios.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103500"},"PeriodicalIF":2.1,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave MotionPub Date : 2025-01-29DOI: 10.1016/j.wavemoti.2025.103503
Tao Xu , Zhijun Qiao
{"title":"The massive Thirring model in Bragg grating: Soliton molecules, breather-positon and semirational solutions","authors":"Tao Xu , Zhijun Qiao","doi":"10.1016/j.wavemoti.2025.103503","DOIUrl":"10.1016/j.wavemoti.2025.103503","url":null,"abstract":"<div><div>The massive Thirring model, which describes pulse propagation in Bragg grating, is systematically investigated through Darboux transformation. Based on the Darboux transformation, we study soliton molecules, breather-positons, and semirational solutions for the massive Thirring model in this paper. What we present includes the following main results: (1) the general multiple soliton molecules (SMs) interaction, namely, <span><math><mi>M</mi></math></span> SMs interact with <span><math><mrow><mo>(</mo><mi>N</mi><mo>−</mo><mi>M</mi><mo>)</mo></mrow></math></span> solitons (<span><math><mrow><mn>0</mn><mo>≤</mo><mi>M</mi><mo>≤</mo><mi>N</mi></mrow></math></span>); (2) higher-order breather-positon solutions whose center region exhibit rogue waves’ patterns; and (3) semirational solutions with arbitrary <span><math><mi>M</mi></math></span>th-order rogue waves and <span><math><mrow><mo>(</mo><mi>N</mi><mo>−</mo><mi>M</mi><mo>)</mo></mrow></math></span>-breathers. Finally, the generating mechanisms and related dynamics of those obtained nonlinear localized waves are discussed in details.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"134 ","pages":"Article 103503"},"PeriodicalIF":2.1,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}