Journal of Sound and Vibration最新文献

{"title":"Planar string vibrations in the presence of smooth curved boundary obstacles at both ends","authors":"Abhishek Sharma,&nbsp;Pankaj Wahi","doi":"10.1016/j.jsv.2025.119049","DOIUrl":"10.1016/j.jsv.2025.119049","url":null,"abstract":"<div><div>This research investigates the planar vibrations of a string with smooth unilateral obstacles placed at both ends. The equation of motion for the system has been derived using the Lagrangian framework. The presence of obstacles at the ends introduces a moving boundary resulting from the wrapping and unwrapping of the string, hence increasing the complexity of the study. It is necessary to implement an appropriate scaling technique on the spatial domain to address the issue of moving boundaries. This scaling method effectively transforms the moving boundary problem into a fixed boundary problem. However, this transformation introduces nonlinearity into the governing equation. The linear vibration characteristics of the system are investigated through the process of linearizing the governing equation around the static configuration of the string. This analysis reveals the harmonic nature of the natural frequencies and their relationship to the geometry of the obstacle. The Galerkin projection method is employed to study the modal interactions, which exhibit significant properties such as amplitude and frequency modulations. A general expression for the reduced system of ordinary differential equations has been developed in such a way that the modal interactions can be studied for a large number of modes. Furthermore, there have been critical observations on the impact of the relative curvature and size of the two obstacles on the modulation frequency and modal interactions. We find that the amplitude modulation frequency due to modal interactions can be tuned depending on the relative size of the two obstacles.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"608 ","pages":"Article 119049"},"PeriodicalIF":4.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the modelling of unsteady flows for efficient prediction of the interaction tones of coaxial counter-rotating rotors","authors":"Siyang Zhong ,&nbsp;Zimo Wang ,&nbsp;Zhida Ma ,&nbsp;Wangqiao Chen ,&nbsp;Peng Zhou","doi":"10.1016/j.jsv.2025.119038","DOIUrl":"10.1016/j.jsv.2025.119038","url":null,"abstract":"<div><div>This paper proposes a prediction model of the unsteady flows induced by the coaxial counter-rotating rotors for the efficient computation of tonal noise. Based on the mean aerodynamic distributions, which can be obtained by the rapid blade element momentum theory, we can evaluate the strengths of the bound vortex and tip vortex. Then, the sectional blades are unwrapped into the 2D domain as two arrays of point vortexes. Particularly, the equivalent point vortexes are assumed to be located on arcs of a sector region since the mutual interaction is unnecessary to take place between sectional blades at the same radii, unlike the previous studies in which the resulting cascades are placed on two parallel straight lines. A conformal mapping is performed to estimate the induced unsteady velocities due to the equivalent bound vortex. Moreover, the influence of the tip vortex on the induced flow and the noise radiation is included. We compare the prediction results with the experimental tests in the anechoic chamber, and fairly good agreements are obtained. Based on a parametric study, we explore the dependence of overall sound pressure based on the predicted multiple tones on the rotating speeds. A scaling law in the form of <span><math><mrow><msup><mrow><mi>p</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>∼</mo><msup><mrow><mrow><mo>(</mo><mrow><mo>(</mo><msub><mrow><mi>RPS</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>+</mo><msub><mrow><mi>RPS</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow><mo>/</mo><mn>2</mn><mo>)</mo></mrow></mrow><mrow><mi>λ</mi></mrow></msup></mrow></math></span> is obtained. The predicted value of <span><math><mi>λ</mi></math></span> is about 5.7, close to a set of available experimental data at some observer angles. However, at observers on the rotating plane and in the downstream direction, there is a clear difference in the experimental and prediction data, suggesting that other mechanisms could contribute to the sound levels at these locations, which should be identified and modelled in future studies.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"607 ","pages":"Article 119038"},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional effects of the wake on wind turbine sound propagation using parabolic equation","authors":"Hemant Bommidala ,&nbsp;Jules Colas ,&nbsp;Ariane Emmanuelli ,&nbsp;Didier Dragna ,&nbsp;Codor Khodr ,&nbsp;Benjamin Cotté ,&nbsp;Richard J.A.M. Stevens","doi":"10.1016/j.jsv.2025.119036","DOIUrl":"10.1016/j.jsv.2025.119036","url":null,"abstract":"<div><div>The influence of three-dimensional (3D) wind turbine wake effects on sound propagation is investigated. To study this, numerical simulations are conducted using a 3D parabolic equation model at low frequencies, with comparisons made to a two-dimensional (2D) approach that neglects transverse horizontal propagation. Three atmospheric stability conditions are investigated using analytical wind profiles that incorporate the wake effects. The wind turbine noise source is specified using an aeroacoustic extended source model. 3D effects due to the wake are shown to be significant, especially for the stable atmosphere. Indeed, horizontal refraction induces focusing that a 2D approach fails at predicting. As the wind turbine blades are rotating, the focal zones are moving accordingly, yielding large variations of the sound levels. Downstream the turbine, amplitude modulation can locally reach values as high as 16.5 dB over long distances. In addition, higher average SPL are predicted by 3D simulations compared to 2D ones, with deviations up to 4.5 dB. For neutral and unstable conditions differences in 2D and 3D sound propagation approaches are smaller, as velocity gradients in the wind turbine wake are smaller.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"608 ","pages":"Article 119036"},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Special self-balancing behavior in a self-synchronous system with both vibration utilization and vibration suppression functions","authors":"Wenchao Hu ,&nbsp;Xueliang Zhang ,&nbsp;Siyuan Yi ,&nbsp;Ruoqing Zhang ,&nbsp;Wenxin Wang ,&nbsp;Bangchun Wen","doi":"10.1016/j.jsv.2025.119062","DOIUrl":"10.1016/j.jsv.2025.119062","url":null,"abstract":"<div><div>In spite of the abundance of literature concerning the synchronization of vibrators, scant attention has been given to effectively solving the vibration dampening of the system through the lens of self-synchronization theory. This paper delves into the realms of synchronization, stability, and self-balancing behavior of a vibrating system with multiple synchronous states driven by four bias vibrators. Utilizing the average method and Hamilton's principle, the synchronization and stability criteria of the four vibrators are deduced. Grounded on the premise of ascertaining whether the theoretical transmission of dynamic loads from the system to the foundation amount to zero, the conditions for self-balancing are explicated. A numerical study unfolds, scrutinizing the effect of bias distance, bias angle, and rotation direction of the vibrator on synchronization states, stability, and self-balancing behavior across varying resonance regions. Some simulations are provided to verify the fidelity of the numerical analyses. Ultimately, the congruence among experimental findings, numerical analyses, and simulation outcomes underscores the soundness of the aforementioned conclusions and methodology employed. These findings indicate that the motion trajectory exhibited in the system in stable states hinges on the synchronization state of the system. Whether propelled by four co-rotating vibrators or counter-rotating counterparts, anchoring the system's operative point in the first sub-resonance region not only can it achieve self-balance effectively but also enables the perfect integration of vibration utilization and vibration suppression without additional vibration isolation strategies.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"608 ","pages":"Article 119062"},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hybrid multilevel fast multipole and equivalent source method for aeroacoustic scattering prediction","authors":"Lican Wang ,&nbsp;Siyang Zhong ,&nbsp;Bao Chen ,&nbsp;Peng Zhou ,&nbsp;Wangqiao Chen ,&nbsp;Xin Zhang","doi":"10.1016/j.jsv.2025.119033","DOIUrl":"10.1016/j.jsv.2025.119033","url":null,"abstract":"<div><div>A hybrid multilevel fast multipole and equivalent source method (FM-ESM) has been developed for efficient aeroacoustic scattering prediction, which is distinguished by its application of the equivalent source concept across all fast multipole stages, including particle-to-multipole, multipole-to-multipole, multipole-to-local, local-to-local, local-to-particle, and particle-to-particle translations. The capability of the method for scattering predictions in two and three dimensions with different flow conditions is demonstrated through an analytical solution utilizing an image source method. Furthermore, the flexibility to reduce the number of equivalent sources is explored during particle-to-multipole and particle-to-particle translations, where the mismatch between equivalent sources and collocation points results in an over-determined system. To iteratively invert the resulting rectangular matrix, a variant of the generalized minimal residual algorithm known as the BA-GMRES method is utilized, accompanied by a specified pre-conditioner. A fast multipole boundary element method is included for reference under the same framework. Through examinations of cylindrical and spherical scattering, it is observed that FM-ESM, with fewer sources, efficiently yields accurate results in cases involving fictitious resonant frequencies. The method’s applicability to large-scale problems makes it a complementary choice for aeroacoustic scattering prediction.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"607 ","pages":"Article 119033"},"PeriodicalIF":4.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the influence of bearing certainty and random elevation on the friction self-excited vibration of ship propeller shaft system","authors":"Chuang Wu ,&nbsp;Xinhua Long ,&nbsp;Dejiang Shang ,&nbsp;Feng Chen","doi":"10.1016/j.jsv.2025.119034","DOIUrl":"10.1016/j.jsv.2025.119034","url":null,"abstract":"<div><div>Considering the random error of bearing installation and random deformation of the hull caused by waves, this paper establishes the probability distribution model of bearing random elevation and the bearing load distribution model, deduces the friction force expression of the stern bearing, puts forward the transverse-torsional coupling friction self-excited vibration model of the propeller shaft system considering the bearing random elevation. Using the proposed model, the influence of bearing determinism and random elevation on the stability and response of friction self-excited vibration of the propeller shaft system is analyzed. Immediately after that, the vibration response of the system under different bearing elevations was tested by using the propeller-shaft experiment bench with adjustable stern bearing position, which verified the accuracy of the model as well as the validity of the analysis results. The analysis results show that, the stability and response of the system self-excited vibration show randomness after considering the bearing random elevation, which is consistent with the characteristics of significant intermittent and uncertain occurrence of friction vibration in the actual ship propulsion system. In addition, the instability critical speed increases by 64 % and the maximum amplitude of self-excited vibration response increases by 120 % after considering the random elevation, which indicates that the random elevation caused by waves is a factor that needs to be emphasized urgently.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"608 ","pages":"Article 119034"},"PeriodicalIF":4.3,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scaling operational modes by modal interpretation of static displacements","authors":"Jiawei Jian,&nbsp;Zhong-Rong Lu,&nbsp;Li Wang,&nbsp;Peiyue Xie","doi":"10.1016/j.jsv.2025.119035","DOIUrl":"10.1016/j.jsv.2025.119035","url":null,"abstract":"<div><div>Operational modal analysis can only identify unscaled mode shapes, limiting further engineering applications. The widely-used mass-change method for modal scaling requires large mass perturbations to generate measurable natural frequency shifts in presence of noise, which however, is difficult and expensive to implement in practical engineering. This paper proposes a novel modal scaling strategy based on static measurement. The main idea of the strategy is to interpret the static displacements produced by a designated loading condition as a linear combination of the unscaled mode shapes. Consequently, the static and dynamic responses are linked together, from which the modal masses (scaling factors) can be identified. A numerically simulated bridge and an experimental cantilever beam demonstrate the effectiveness and superiority of the proposed strategy.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"607 ","pages":"Article 119035"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian modal identification of non-classically damped systems using frequency domain data","authors":"Shakir Rather ,&nbsp;Sahil Bansal","doi":"10.1016/j.jsv.2025.119039","DOIUrl":"10.1016/j.jsv.2025.119039","url":null,"abstract":"<div><div>In this study, we present two Bayesian frequency-domain methods for identifying the complex modal parameters of a linear dynamic system from ambient vibration data. The identification of complex modal parameters is applicable to both classically and non-classically damped systems, in contrast to the identification of real modal parameters, which is restricted to classically damped systems. This study investigates the statistical properties of the response spectral density estimator and the response Discrete Fourier Transform (DFT) to formulate Bayesian probabilistic approaches for modal identification. These approaches involve finding the optimal modal parameters and their associated uncertainties by calculating the joint posterior Probability Density Function (PDF) of the modal parameters for given measured data and modeling assumptions. Identification strategies for both closely-spaced and well-separated modes are provided and the respective mathematical analyses are presented. Derivation of analytical expressions for computing the gradient and Hessian of the objective function is included. The validation of the developed approach is done through simulated examples and an experimental study.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"608 ","pages":"Article 119039"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sound radiation from piping systems in enclosures: Its prediction and management","authors":"Xiangliang Wang,&nbsp;Hongkuan Zhang,&nbsp;Zhanyu Li,&nbsp;Yun Ma,&nbsp;Gengkai Hu","doi":"10.1016/j.jsv.2025.119050","DOIUrl":"10.1016/j.jsv.2025.119050","url":null,"abstract":"<div><div>In enclosures, the interior sound field driven by the piping systems severely reduces living comfort. Although commercial finite element softwares have been widely used, their high computational cost, especially in the optimization process, greatly limits its efficiency in practical applications. This research proposes a novel and fast analytical framework aimed at efficiently predicting the interior sound field. This analytical framework first idealizes a vibrating pipe per unit length as a dipole source ignoring water-borne noise inside the pipe, and further linearly superimposes such elements along the pipe axis to obtain a dipole line source. Finally, the modal expansion method is used to calculate the interior sound field driven by the dipole line source, where pipe's diameter should be much smaller than the wavelength. As a result, our theoretical framework is validated both by finite element method and elaborately designed acrylic enclosure experiments, which has demonstrated high computational accuracy and significant computational efficiency advantages. Furthermore, we utilize this framework to efficiently optimize the interior sound field in a cuboid enclosure to obtain a quiet area. This study offers a promising strategy for quickly assessing sound radiation of piping systems and makes their acoustic optimization possible.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"607 ","pages":"Article 119050"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aerodynamic noise simulation of porous medium-coated cylinder: Broadband hump noise mechanism and effects of permeability and pores distribution on tonal noise","authors":"Weimeng Kong ,&nbsp;Jin Zhang ,&nbsp;Peiqing Liu","doi":"10.1016/j.jsv.2025.119046","DOIUrl":"10.1016/j.jsv.2025.119046","url":null,"abstract":"<div><div>The porous medium layer can effectively control the aerodynamic noise generated by the flow around a cylinder. To analyze the internal flow within porous media and the impact on aerodynamic noise, a quasi-microscopic porous medium model composed of a square cylinder array is adopted. Based on the lattice Boltzmann method (LBM), simulations under different porosities and pores per inch (PPI) at <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>8.2</mn><mspace></mspace><mo>×</mo><msup><mrow><mn>10</mn></mrow><mn>4</mn></msup></mrow></math></span> have been performed. The results indicate that the porous medium induces additional mid-to-high-frequency broadband hump noise, which is generated from vortex shedding of the porous medium skeleton units (PSUs). This study investigates the impact of varying permeability on the frequency and maximum sound pressure level (SPL) of tonal noise while keeping effective mean diameter and porosity constant respectively. With a fixed effective mean diameter, an increase in permeability leads the frequency and maximum SPL of tonal noise firstly decreasing and then stabilization. Under a fixed porosity, no discernible correlation is observed between variations in the permeability and the maximum SPL and frequency of tonal noise. The research on PPI reveals that the circumferential PPI does not exert a significant influence on tonal noise maximum SPL, and reducing radial PPI yields a substantial decrease in tonal noise maximum SPL.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"607 ","pages":"Article 119046"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}