Journal of Fluids and Structures最新文献

{"title":"Pressure and flow patterns during multiple-order vertical vortex-induced vibrations of a 6:1 rectangular cylinder","authors":"Lin Zhao ,&nbsp;Tingshu Han ,&nbsp;Chuanxin Hu ,&nbsp;Song Luo ,&nbsp;Qiang Zhou ,&nbsp;Wei Cui","doi":"10.1016/j.jfluidstructs.2025.104314","DOIUrl":"10.1016/j.jfluidstructs.2025.104314","url":null,"abstract":"<div><div>Rectangular cross-sections have been typically used to investigate vortex-induced vibration (VIV) mechanism of bluff bodies, which provides important reference for wind-resistant design of engineering structures, such as high-rise buildings and long-span bridges. A numerical simulation was conducted in order to examine the multiple-order vertical VIV mechanism of a 6:1 rectangular cylinder, and the surface wind pressure distribution characteristics and surrounding flow field were particularly focused. This rectangular cylinder has two VIV lock-in regions. According to the surface pressure distribution characteristics, it is deduced from the proposed simplified vortex theory that there are significant vortices drifting on the upper and lower surfaces of the rectangular cylinder, and the vortex experiences approximate two and one vibration period drifting from the leading edge to the trailing edge in the first and second lock-in region, respectively. More characteristics of the flow field are revealed by dynamic mode decomposition (DMD) method. The front three non-zero DMD mode frequencies are about 1–3 times of the natural frequency of the rectangular cylinder, respectively. Multiple vortices are also observed on the upper and lower surfaces in the high-order DMD modes, especially in the second lock-in region, indicating the importance of vortex drifting phenomenon in the occurrence of VIV. This investigation provides a deeper viewpoint combining surface pressure distribution characteristics and surrounding flow patterns, which is of important reference for revealing the VIV mechanism of wind-sensitive structures with bluff body cross-sections.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104314"},"PeriodicalIF":3.4,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761181","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":"An enhanced SPH-based hydroelastic FSI solver with structural dynamic hourglass control","authors":"Yi Zhan ,&nbsp;Min Luo ,&nbsp;Abbas Khayyer","doi":"10.1016/j.jfluidstructs.2025.104295","DOIUrl":"10.1016/j.jfluidstructs.2025.104295","url":null,"abstract":"<div><div>This paper presents an enhanced hydroelastic FSI (Fluid-Structure Interaction) solver based on the open-source SPH (Smoothed Particle Hydrodynamics) code DualSPHysics+. For the structure model, a second-order discretization of the deformation gradient tensor (F2nd) is implemented to improve the accuracy of stress and strain computation. To mitigate numerical noises in the reproduced stress fields and improve numerical stability, a Riemann Stabilization (RS) term is incorporated in the structural momentum equation. A Dynamic Hourglass Control (DHGC) scheme being parameter-free is proposed to mitigate the spurious zero-energy modes linked with rank deficiency as a challenging issue for collocated computational methods including the total Lagrangian SPH. The novelty of this scheme is that it dynamically adjusts the hourglass control coefficient based on the instantaneous state of particle distributions and time evolution of an error function. For the fluid model, the Velocity divergence Error Mitigating (VEM) scheme and Hyperbolic/Parabolic Divergence Cleaning (HPDC) scheme are adopted to suppress spurious fluid pressure noises and hence enhance the modelling of fluid-structure interactions. Validations in terms of robustness and accuracy of the proposed model are carried out via five structure examples and three FSI ones. The results demonstrate that more physically consistent stress and strain fields are reproduced by the implementation of F2nd and RS. The proposed DHGC scheme effectively suppresses hourglass modes and is case- and resolution-independent (in contrast to the traditional Hourglass Control scheme). The incorporation of the VEM and HPDC mitigates fluid pressure noises and further enhances the accuracy of FSI simulations.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104295"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738974","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":"Nonlinear free vibrations of a nanocomposite micropipes conveying laminar flow subjected to thermal ambient: Employing invariant manifold approach","authors":"Peijun Zhang ,&nbsp;Wenchen Shao ,&nbsp;Hadi Arvin ,&nbsp;Wen Chen ,&nbsp;Wenjing Wu","doi":"10.1016/j.jfluidstructs.2025.104311","DOIUrl":"10.1016/j.jfluidstructs.2025.104311","url":null,"abstract":"<div><div>This research presents, for the first time, essential insights into the free vibrations of a composite micropipe enriched by means of graphene sheets (a GRC micropipe) conveying laminar flow subjected to a thermal ambient, preparing precious discernment for designers and engineers. The study develops the governing equations in the framework of the Euler–Bernoulli beam theory, the modified couple stress theory (MCST), von-Karman nonlinear relations for strains, and revised Halpin–Tsai relationships. Taking the advantage of invariant manifold procedure the two-degrees-of-freedom (DOFs) discretized governing equations, coupled gyroscopically, are reduced efficiently to one nonlinear governing equation with inertial nonlinearity that coping with it is considerably simpler. Leveraging the method of multiple scales (MMS) the nonlinear natural frequency, along with the accompanying nonlinearity constant is disclosed. It is underscored that the contribution of layer stacking on the vibrational behavior of GRC micropipes carrying laminar flow is substantially highlighted when the GRC micropipe is subjected to a thermal medium. It is observed that although it is expected to have a larger fundamental linear natural frequency for an FGV GRC micropie, at low temperatures UD GRC micropipe has the largest one for thin micropipes. It is shown that the hardening behavior of the first mode of the GRC micropipe is alleviated regarding the small scale factor while it is intensified regarding the flow profile effect. In sum imposing both factors relieves the first mode hardening behavior.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104311"},"PeriodicalIF":3.4,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687446","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":"Digital twin-empowered investigation on limit cycle flutter of a double-girder bridge section","authors":"Bo-Man Cheng ,&nbsp;You-Lin Xu ,&nbsp;Guang-Zhong Gao ,&nbsp;Hao-Yang Li ,&nbsp;Le-Dong Zhu","doi":"10.1016/j.jfluidstructs.2025.104309","DOIUrl":"10.1016/j.jfluidstructs.2025.104309","url":null,"abstract":"<div><div>The investigation of limit cycle flutter (LCF) in a bridge section is currently conducted through the utilization of both wind tunnel testing and numerical simulation techniques, specifically during the design stage of a bridge. In consideration of the drawbacks and uncertainties to both wind tunnel testing and numerical simulations, this paper presents a digital twin-empowered investigation on LCF of a double-girder bridge section. While the computational fluid dynamics (CFD) simulation for the bridge section as a fluid-structure coupling model is viewed as a virtual entity, the wind tunnel testing of the bridge section is considered a physical entity. Based on the multivariate polynomial regression iterative optimization algorithm, the data collected from the physical entity is mingled with the virtual entity to achieve a digital twin of LCF at a given wind velocity. Subsequently, the Kriging interpolation is employed for the purpose of establishing a digital twin system, which is designed to simulate and predict LCF in the bridge section under conditions of wind velocity that have not been tested in the wind tunnel testing or exceed the measurement capacity of wind tunnel test. The findings of this research demonstrate that a digital twin-empowered investigation is feasible and greatly enhances the prediction quality and capacity of LCF of the double-girder bridge section.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104309"},"PeriodicalIF":3.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687443","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":"Wave diffraction and radiation by a vertical cylinder standing near a floating elastic plate","authors":"Z.F. Li ,&nbsp;Y.G. Sun ,&nbsp;Y.Y. Shi ,&nbsp;D.Z. Ning","doi":"10.1016/j.jfluidstructs.2025.104310","DOIUrl":"10.1016/j.jfluidstructs.2025.104310","url":null,"abstract":"<div><div>Wave diffraction and radiation problems by a vertical cylinder standing near a floating elastic plate are considered. The linearized velocity potential theory is used to describe the fluid flow, and the thin elastic plate model is adopted for the elastic plate. The numerical solution procedure starts from dividing the fluid domain into two sub-domains, one below free surface and the other below the elastic plate. In the vertical direction, the velocity potential is expanded into a series of eigenfunctions based on separation of variables, which decomposes the three-dimensional problem into an infinite number of coupled two-dimensional problems in the horizontal plane. In the two sub-domains, each of two-dimensional problem is transformed into an integral equation. On the artificial vertical surface between two subdomains, an orthogonal inner product is applied for the eigenfunctions, and the edge conditions of elastic plate are satisfied. On the vertical surface of cylinder, similar inner product is adopted, and the boundary condition on the cylinder surface is imposed. A combined boundary element method and finite difference scheme is introduced to solve the integral differential equations numerically. Extensive results for the hydrodynamic force are provided and analyzed. It is found that the hydrodynamic force is highly oscillatory due to the complex interactions between cylinder and plate.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104310"},"PeriodicalIF":3.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687445","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":"Exploring optimal spacing in parallel fully-passive flapping-foil hydrokinetic turbines","authors":"Siham Eddine Zantoute ,&nbsp;Leandro Duarte ,&nbsp;Guilhem Dellinger ,&nbsp;Nicolas Dellinger ,&nbsp;Mathieu Olivier ,&nbsp;Guy Dumas ,&nbsp;Abdellah Ghenaim ,&nbsp;Abdelali Terfous","doi":"10.1016/j.jfluidstructs.2025.104304","DOIUrl":"10.1016/j.jfluidstructs.2025.104304","url":null,"abstract":"<div><div>The increasing global demand for sustainable energy has led to the exploration of hydrokinetic systems, particularly flapping foil turbines, which utilize fluid–structure interactions to harvest energy from water flows. This study investigates the optimization of spacing between fully passive oscillating foils arranged in parallel configuration to maximize energy extraction efficiency. Utilizing numerical simulations with OpenFOAM’s overset mesh and URANS methods, the research examines the hydrodynamic performance and interaction effects of varying foil spacings, ranging from 3 to 15 chord lengths. For a specific configuration of a stall-flutter flapping foil turbine, results reveal that closer spacings (e.g., 3 chord lengths) can achieve comparable results to single-foil configurations, with solo efficiency <span><math><mrow><mi>η</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>299</mn></mrow></math></span> and parallel efficiency <span><math><mrow><mi>η</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>304</mn></mrow></math></span>. The study further identifies a 15% increase in mean power coefficient at a spacing of <span><math><mrow><msup><mrow><mi>d</mi></mrow><mrow><mo>∗</mo></mrow></msup><mo>=</mo><mn>5</mn></mrow></math></span>, linked to higher heave amplitude and strong fluid–structure interactions. The study highlights the potential of dual-foil setups to improve structural integrity and adaptability in diverse natural water currents. These findings offer valuable insights for the design and operation of hydrokinetic turbines, enhancing their feasibility as a sustainable energy solution.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104304"},"PeriodicalIF":3.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687444","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":"Experimental investigation on fluid–structure interaction in highly flexible wings","authors":"Mostafa Khazaee Kuhpar,&nbsp;Hadi Samsam-Khayani,&nbsp;Banafsheh Seyed-Aghazadeh","doi":"10.1016/j.jfluidstructs.2025.104296","DOIUrl":"10.1016/j.jfluidstructs.2025.104296","url":null,"abstract":"<div><div>This paper presents a comprehensive experimental investigation of fluid-structure interactions in a flexible, high-aspect-ratio wing during its post-critical phase, spanning a reduced velocity range of <span><math><mrow><msup><mrow><mi>U</mi></mrow><mrow><mo>∗</mo></mrow></msup><mo>=</mo><mn>1</mn><mo>.</mo><mn>47</mn><mo>−</mo><mn>35</mn><mo>.</mo><mn>34</mn></mrow></math></span> and corresponding Reynolds number range of <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>146</mn><mo>−</mo><mn>3</mn><mo>,</mo><mn>499</mn></mrow></math></span>. The angle of attack of the wing was systematically varied from 0° to 20° in increments of 2°. The structural dynamics results reveal that changes in the angle of attack significantly affect the onset of limit cycle oscillations, as well as the dominant oscillation frequencies and mode shapes. At higher flow velocities and angles of attack, a significant increase in tip deflection was observed, while minimal deflection occurred at lower or zero angles of attack. In addition to examining the structural responses, the study employs volumetric, time-resolved particle tracking velocimetry (TR-PTV) to investigate the three-dimensional (3-D) flow field around the wing and its wake. Vortex behavior and its interactions with the structural modes varied with different angles of attack and reduced velocities. Leading and trailing edge vortices adapt to wing deflection, particularly at higher angles, and the coherence of these vortical structures was shown to be influenced by the amplitude and mode shape of the wing’s oscillations.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104296"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621495","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":"Adjoint-based shape optimization using lattice Boltzmann method for flow and sound control in tandem cylinders","authors":"Kazuya Kusano,&nbsp;Hiroki Yamaguchi","doi":"10.1016/j.jfluidstructs.2025.104308","DOIUrl":"10.1016/j.jfluidstructs.2025.104308","url":null,"abstract":"<div><div>Aerodynamic noise control for flows with multiple bluff bodies is important in applications such as the pantographs of high-speed trains and landing gears of aircraft. In this study, aeroacoustic shape optimization is performed to develop an effective passive control technique for mitigating the flow-induced sound generated by a cylinder in the wake of another cylinder, focusing on two-dimensional laminar flow past two tandem cylinders at Reynolds and Mach numbers of 160 and 0.2, respectively. The shape optimization aimed at minimizing sound generation employs the lattice Boltzmann method and the unsteady adjoint method. The results highlight the benefits of diminishing the front surface curvature and adding protrusions to the side surfaces of the downstream cylinder. These changes suppress flow acceleration and negative pressure fluctuations when the stagnation point shifts owing to upstream wake oscillation, while mitigating positive pressure fluctuations through an increased flow velocity near the shifted stagnation point. Consequently, the modifications lead to a reduction in lift fluctuations and dipole sound generation, achieving a sound reduction of 2.4 dB compared to the original circular shape. However, the optimized shape significantly increases the mean drag force, indicating a trade-off in the passive control strategy.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104308"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A THINC-based numerical model for incompressible flows with free surfaces on the overset grids: On preserving accuracy and conservation of volume fraction","authors":"Xin Tong ,&nbsp;Dezhu Chen ,&nbsp;Lidong Cheng ,&nbsp;Bin Xie","doi":"10.1016/j.jfluidstructs.2025.104294","DOIUrl":"10.1016/j.jfluidstructs.2025.104294","url":null,"abstract":"<div><div>In this paper, we develop an accurate and robust numerical model for incompressible multiphase flows with free surface on the unstructured overset grids within the framework of OpenFOAM. To capture the moving interface between two immiscible fluids, THINC/QQ (THINC method with quadratic surface representation and Gauss quadrature) scheme is presented on the static and dynamic overset grids using the volume of fluid (VOF) method. A novel interpolation algorithm is proposed to transfer the volume fraction across the overset grids, which significantly improves the geometric faithfulness and numerical conservation of free surfaces since the interface is reconstructed and represented as quadratic surface in the fringe cells of the overset grids using the THINC formulation. A pseudo-Laplacian approach is utilized to interpolate both the velocity and pressure fields across overset grids achieving a second-order accuracy. The incompressible Navier–Stokes equations are solved together with a transport equation of volume fraction using second-order finite volume schemes, which then is coupled with the motion solver during each time step to obtain converged solution between the hydrodynamic flow and kinematic motion of the rigid body. The so-called thincFoam/overset, when used in the transient simulation of interfacial multiphase flows, provides high-fidelity solutions with an order of magnitude reduction in the conservation error of volume fraction field. Numerical verifications have been carried out through various 2D and 3D benchmark tests, such as the water entry of a wedge, floating structure in regular waves, and water entry of a horizontal cylinder. The numerical results demonstrate that the present model shows great potential in capturing complex moving interfaces undergoing large deformations and topological changes with excellent conservation for simulating the nonlinear interaction between multiphase flows and solid structures.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104294"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621494","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":"Effect of corner modifications on galloping-induced response and galloping force of 3:2 rectangular section","authors":"Xiu-Yu Chen ,&nbsp;Le-Dong Zhu ,&nbsp;Qing Zhu","doi":"10.1016/j.jfluidstructs.2025.104305","DOIUrl":"10.1016/j.jfluidstructs.2025.104305","url":null,"abstract":"<div><div>Corner modifications play a significant role in influencing the galloping instability of rectangular sections, as highlighted in prior aerodynamic studies. This research focuses on the effects of various notched and chamfered corner modifications on the galloping behavior of a rectangular section with a side ratio of 3:2, offering a novel perspective by examining these modifications from an aeroelastic force standpoint. Wind tunnel experiments were conducted to simultaneously measure the galloping forces and displacements of the section under uniform flow. The results reveal that, similar to sharp-corner rectangular sections, the onset wind velocities of modified-corner sections deviate from the quasi-steady critical wind velocities for galloping and instead align with those associated with vortex-induced resonance. Among the modifications, notched corners are shown to be more effective than chamfered corners in reducing galloping amplitudes, with smaller notches significantly diminishing amplitudes and larger notches completely suppressing galloping divergence. Using a robust mathematical model for galloping forces, the underlying mechanism of the suppression effect due to corner modifications is elucidated. The superior suppression effect of notched corners, compared to chamfered corners, is attributed to their greater influence on high-order aerodynamic damping. This study extends previous findings by emphasizing the differences between sharp-corner and corner-modified rectangular sections, providing new insights into galloping mitigation strategies.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"135 ","pages":"Article 104305"},"PeriodicalIF":3.4,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621493","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}