Journal of Fluids and Structures最新文献

{"title":"A hydroelastic fluid-structure interaction solver based on a coupled 3D SPH-FEM method","authors":"Xin Chen ,&nbsp;Jie Cui ,&nbsp;Ji-Yang Li ,&nbsp;Peng-Cheng Shi","doi":"10.1016/j.jfluidstructs.2025.104366","DOIUrl":"10.1016/j.jfluidstructs.2025.104366","url":null,"abstract":"<div><div>The present work is aimed at developing an accurate numerical self-programming framework to simulate the violent 3D fluid-structure interaction process by a coupled Lagrangian particle method and mesh-based method, where the hydrodynamic load is solved by smoothed particle hydrodynamics (SPH) and the structural dynamics is predicted by the Finite Element method (FEM). It should be noted that the degenerated continuum theory is introduced to describe the structure dynamics, which can be easily applied to the complex structure discretization in some cases. And at the same time, a normal flux approach is developed to overcome the shortcoming of support domain truncation for fluid particles near the fluid-structure interface. Additionally, some other advanced numerical processing techniques are employed to improve the coupling stability and robustness of the 3D SPH-FEM solver, such as the δ-SPH model and the conventional sequential staggered algorithm. Finally, through several typical hydro-elastic benchmark tests and commercial software tests, including the hydrostatic water column test, free surface flow-structure interaction and elastic structure water entry slamming test, the numerical accuracy and overall stability are discussed and verified systematically, which can promote the numerical algorithm research on hydro-elastic effect in ocean engineering.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104366"},"PeriodicalIF":3.4,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271201","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":"Deep learning vortex-induced vibrations: Time-space forecasting with transformers","authors":"Andreas P. Mentzelopoulos ,&nbsp;Ioannis Papakalodoukas ,&nbsp;Dixia Fan ,&nbsp;Themistoklis P. Sapsis ,&nbsp;Michael S. Triantafyllou","doi":"10.1016/j.jfluidstructs.2025.104337","DOIUrl":"10.1016/j.jfluidstructs.2025.104337","url":null,"abstract":"<div><div>A transformer-based deep neural network is developed to forecast vortex-induced vibrations (VIV) of flexible cylinders. The model is trained on experimental data of uniform (i.e constant diameter) and tapered (i.e. linearly varying diameter) flexible cylinder models, with the latter exhibiting multi-frequency vibrations.</div><div>The network forecasts VIV across the full structure with high accuracy for both monochromatic and multi-frequency vibrations and generalizes to unseen flow conditions. Requiring only sparse inputs from spatial measurements, the model predicts the full structural response over time, demonstrating potential as the computational driver of a digital twin for vibrating bodies.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104337"},"PeriodicalIF":3.4,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144231204","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":"Scattering of obliquely incident waves by a half-submerged horizontal cylinder in a two-layer fluid","authors":"Minakshi Ghosh,&nbsp;Dilip Das","doi":"10.1016/j.jfluidstructs.2025.104341","DOIUrl":"10.1016/j.jfluidstructs.2025.104341","url":null,"abstract":"<div><div>This study investigates wave energy scattering by a half-immersed horizontal cylinder in a two-layer fluid with distinct densities related to offshore renewable energy projects. Linear water wave theory and multipole expansions have been used to derive analytical expressions for wave reflection and transmission coefficients corresponding to incident waves of the two wavenumbers. Graphical representations of the numerical results highlight the oscillatory behaviour with the effect of the incident wave angle and the height of the upper fluid layer on the wave energy distribution, demonstrating the importance of considering density differences in wave–structure interaction studies. This research is essential for enhancing wave energy converters’ efficiency and structural integrity in multilayered fluids, particularly for emerging projects in Indian waters.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104341"},"PeriodicalIF":3.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223232","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":"Suppressing shock-induced oscillations of a compliant panel with viscoelastic materials","authors":"C. Riveiro Moreno ,&nbsp;M. Couliou ,&nbsp;N. Fabbiane ,&nbsp;R. Bur ,&nbsp;O. Marquet","doi":"10.1016/j.jfluidstructs.2025.104335","DOIUrl":"10.1016/j.jfluidstructs.2025.104335","url":null,"abstract":"<div><div>The influence of structural viscosity on the fluid–structure interaction between a normal shock-wave and a compliant panel is investigated. Two compliant panels are designed to allow significant static deformation while exhibiting different dynamic behaviors. For this purpose, two distinct elastomeric materials are used based on their dynamic responses within the shock oscillation frequency range: polyurethane 40A for the elastic panel and Tango Polyjet 61A for the viscoelastic panel. Dynamic mechanical analyses characterize the materials’ dynamic properties, enabling the evaluation of natural vibration modes and frequencies of both structures. The elastic panel exhibits natural vibration frequencies that align with the ones of the natural oscillations of the shock-wave. Wind-tunnel experiments reveal strong dynamic coupling between the elastic panel and the shock-wave, leading to large-amplitude, synchronized oscillations when the shock is centered on the panel. In contrast, the viscoelastic panel is designed to avoid the fluid–structure coupling observed in the elastic panel. The marked viscoelastic properties of the material shift the natural vibration modes to higher frequencies, outside the shock-wave’s natural oscillation range. As a result, in its interaction with the shock-wave, the viscoelastic panel exhibits only a large static deformation – greater than that of the elastic panel – without any dynamic fluid–structure coupling, regardless of the shock position. These findings demonstrate that viscoelastic materials hold significant potential for flow control applications, providing structural damping and frequency-dependent stiffening, which effectively decouple static deformation from dynamic interaction. Our results suggest that viscoelastic panels could be optimized as adaptive bumps for shock control, responding to fluid dynamics without inducing unwanted dynamic coupling.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104335"},"PeriodicalIF":3.4,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203018","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":"Numerical investigation on the twisted wind-induced aeroelastic response of a square supertall building","authors":"Bowen YAN ,&nbsp;Qiaowen Ran ,&nbsp;Yangjin Yuan ,&nbsp;Hongyu Ren ,&nbsp;Xiao Li ,&nbsp;Xuhong Zhou ,&nbsp;Qingshan Yang ,&nbsp;Qingkuan Liu","doi":"10.1016/j.jfluidstructs.2025.104350","DOIUrl":"10.1016/j.jfluidstructs.2025.104350","url":null,"abstract":"<div><div>The aerodynamic and aeroelastic characteristics of a square supertall building and the surrounding wind field are numerically analyzed, accounting for the influence of the twisted wind field (TWF). A two-way coupled fluid-structure-interaction (FSI) simulation, validated by the aeroelastic experiments conducted in both TWF and conventional wind field (CWF), is employed to fulfill this purpose. This study focuses on the effect of TWF on the vortex-induced vibration (VIV) response of the building and associated aerodynamic forces acting on the aeroelastic model. The results indicate that the fluctuating forces on the tall building are reduced significantly when it is immersed in TWF compared to those in CWF. In TWF, the spectral energy of the across-wind force is dispersed over a wider frequency range than that in the CWF. Furthermore, the aeroelastic response of the building in the TWF is restricted at the upper range of the reduced wind velocity, attributed to the disordered and twisted wake flow near the building. The findings from the present study can enhance the understanding of the VIV behavior of super-tall buildings under the effect of twisted winds.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104350"},"PeriodicalIF":3.4,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190232","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":"DeepVIVONet: Using deep neural operators to optimize the location of sensors with application to vortex-induced vibrations","authors":"Ruyin Wan ,&nbsp;Ehsan Kharazmi ,&nbsp;Michael S. Triantafyllou ,&nbsp;George Em Karniadakis","doi":"10.1016/j.jfluidstructs.2025.104330","DOIUrl":"10.1016/j.jfluidstructs.2025.104330","url":null,"abstract":"<div><div>We introduce DeepVIVONet, a new framework for optimal dynamic reconstruction and forecasting using field data of the vortex-induced vibrations (VIV) of a marine riser. We demonstrate the effectiveness of DeepVIVONet in accurately reconstructing the motion of an off–shore marine riser by using sparse spatio-temporal measurements. We also show the generalization of our model in extrapolating to other flow conditions via transfer learning, underscoring its potential to streamline operational efficiency and enhance predictive accuracy. The trained DeepVIVONet serves as a fast and accurate surrogate model for the marine riser, which we use in an outer-loop optimization algorithm to obtain the optimal locations for placing the sensors. Furthermore, we employ an existing sensor placement method based on proper orthogonal decomposition (POD) to compare with our data-driven approach. We find that that while POD offers a good approach for initial sensor placement, DeepVIVONet’s adaptive capabilities yield more precise and cost-effective configurations.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104330"},"PeriodicalIF":3.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190231","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 Laplace domain method for estimating wave elevation from the transient motion responses of floating structures","authors":"Jinwei Sun ,&nbsp;Sau-Lon James Hu ,&nbsp;Huajun Li","doi":"10.1016/j.jfluidstructs.2025.104338","DOIUrl":"10.1016/j.jfluidstructs.2025.104338","url":null,"abstract":"<div><div>Estimating sea state based on the responses of floating structures to ocean waves has been extensively studied, with traditional methods primarily focusing on the frequency and time domains. Frequency domain techniques, which estimate wave spectra, assume stationary sea state and response, while time domain methods can capture time-varying wave elevations from short-term response measurements but often overlook transient components, leading to potential inaccuracies. This paper presents an innovative Laplace domain method that employs pole–residue operations to reconstruct input wave elevation. By utilizing a transient sampled motion signal and the pole–residue representation of the wave–structure system, the approach formulates a well-conditioned set of simultaneous linear equations to solve for the unknown input. In this matrix formulation, the system’s poles and residues provide the coefficients, while the sampled output signal forms the right-hand side vector. The effectiveness of this method is demonstrated through two numerical examples: a single-degree-of-freedom (SDOF) Spar model under irregular wave conditions and a 6-DOF Floating Production Storage and Offloading (FPSO) system exposed to a wave spectrum.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104338"},"PeriodicalIF":3.4,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167569","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":"Stability of falling flyers","authors":"Sung-Ik Sohn","doi":"10.1016/j.jfluidstructs.2025.104336","DOIUrl":"10.1016/j.jfluidstructs.2025.104336","url":null,"abstract":"<div><div>The motion of falling <span><math><mo>∨</mo></math></span>-flyers is studied using an inviscid vortex shedding model. The body and vortices separated from the edge of the body are described by vortex sheets. The model provides a highly resolved vorticity field of the flow. We investigate the stability of falling flyers for various physical parameters. At high Reynolds numbers, the dynamics of falling bodies are characterized by the Froude number, which represents the relative importance of body inertia. We consider four folding angles of the wings: <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>,</mo><mn>2</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>,</mo><mn>3</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>, and 45°, with the Froude number <span><math><mrow><mtext>Fr</mtext><mo>=</mo><mn>1</mn></mrow></math></span>. Our results show significant differences in the stability of flyers for varying the folding angle. For <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>, the oscillation of the side-to-side motion increases rapidly, whereas for <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>2</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> and 30°, the flyers fall similarly and the oscillation increases much more slowly than in the case of <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>. For <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>4</mn><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>, the flyer falls stably at early times, but the oscillation later grows rapidly. We also examine the effects of varying the Froude number and the center of mass of the body, with a fixed angle of <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>2</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>. The flyer maintains a side-to-side oscillation for <span><math><mrow><mtext>Fr</mtext><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, whereas it becomes unstable and eventually flips for <span><math><mrow><mtext>Fr</mtext><mo>=</mo><mn>2</mn></mrow></math></span>. It is found that lowering the center of mass stabilizes the flyer, whereas heightening the center of mass destabilizes it. The results on the flyer’s stability have practical implications in real-world applications such as air-gliders and bio-inspired flyers.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"137 ","pages":"Article 104336"},"PeriodicalIF":3.4,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147197","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":"Characteristics of lift forces on circular-sectioned tall structure at high Reynolds number based on full-scale measurement","authors":"Lei Wang ,&nbsp;Zi-xia Wang ,&nbsp;Jie Song ,&nbsp;Tong Guo ,&nbsp;Liang-hao Zou ,&nbsp;Shu-guo Liang","doi":"10.1016/j.jfluidstructs.2025.104349","DOIUrl":"10.1016/j.jfluidstructs.2025.104349","url":null,"abstract":"<div><div>The lift force is an important aerodynamic parameter for tall structures with circular cross-section. Due to the difficulty of achieving high Reynolds number (<em>Re</em>) in wind tunnel, acquiring characteristics of lift forces at high <em>Re</em>, especially for the transcritical range, is usually realized by full-scale measurement. As a complement to the previous studies about lift forces based on full-scale measurement at high <em>Re</em>, the present study conducts full-scale measurement on a 210m high chimney to acquire lift force data. Characteristics of lift forces on the circular structure with high <em>Re</em> are then examined in terms of standard deviation of lift force coefficient and Strouhal number (<em>St</em>). A discussion on lift force and <em>St</em> is then carried out based on the data of both the present full-scale measurement and literature. Results of lift force and <em>St</em> show considerable discrepancy, even for the same <em>Re</em>. Some invalid data are then refined by considering the effect of measurement conditions and structural response, to decreases the scatter of lift forces and hence provide more accurate reference for the application of the data in the design.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"136 ","pages":"Article 104349"},"PeriodicalIF":3.4,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137929","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":"Re-scaling of a fractional step method for low Reynolds number flows and fluid-structure-interaction","authors":"Utkarsh Mishra,&nbsp;Iman Borazjani","doi":"10.1016/j.jfluidstructs.2025.104331","DOIUrl":"10.1016/j.jfluidstructs.2025.104331","url":null,"abstract":"<div><div>Fractional step methods, even with implicit time integration, suffer from severe time step restrictions at low Reynolds numbers (<span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span>). Our analysis shows the splitting error of the implicit fractional step method is inversely proportional to the Reynolds number, which results in the time step restriction. Our solution involves introducing a new Reynolds number scaling in the fractional step method, which eliminates the restriction on time step size without sacrificing the accuracy of the results. We demonstrate the power of this simple scaling in two cases at low Reynolds numbers: (1) flow through a channel commonly encountered in microfluidic applications, and (2) fluid-particle interaction commonly arises in suspensions of micro- or nano-particles. Our results show that, with the new scaling, simulations for Reynolds numbers as low as <span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span> = 0.0001 can be conducted using the same time step as for <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>1</mn></mrow></math></span>, which increases the size of time steps by 10000 folds, thereby reducing the computational cost/time. This simple re-scaling can easily be implemented in any fractional-step method.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"136 ","pages":"Article 104331"},"PeriodicalIF":3.4,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131061","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}