Journal of Fluids and Structures最新文献

{"title":"Modeling and simulation of shock wave-vehicle interaction in hyperloop tubes with shock attenuation via pseudo-perforated tube wall","authors":"Rajdeep Deb","doi":"10.1016/j.jfluidstructs.2026.104502","DOIUrl":"10.1016/j.jfluidstructs.2026.104502","url":null,"abstract":"<div><div>Shock wave generated due to fast moving vehicle inside Hyperloop tube is studied, especially for its interaction with structures such as tube end wall and vehicle. The generation of corresponding reflection waves and its properties are estimated using analytical modeling based on the nozzle analogy and piston analogy. The interaction of reflection wave with vehicle and its corresponding impact on vehicle drag and flow properties around the vehicle is estimated using unsteady Reynolds-averaged Navier Stokes (URANS) equations. The parametric study of vehicle drag and reflection wave properties is obtained for varying blockage ratio (<em>BR</em>), vehicle speed (<em>U_v</em>), tube pressure (<em>p_t</em>), and vehicle geometry. The supersonic conditions developed in the vehicle tail are found to be modified due to interaction of vehicle with reflection wave, and multiple oblique shocks are observed behind the vehicle with increased blockage ratio and vehicle speed. In addition, secondary reflection wave propagating ahead of vehicle due to interaction with shock waves leads to pressure rise ahead of vehicle. As a consequence, an instantaneous rise in drag is observed. The mitigating measure to deal with the corresponding decrease in vehicle speed is estimated based on Proportional-Integral-Derivative (PID) control theory. The PID parameters are calculated, and the timescale for vehicle speed control is studied for varying control parameters. Special features on the tube wall of type pseudo-perforated wall are simulated to obtain reduced shock strength and shock speed for incident and reflecting waves. It is observed that such features of the tube wall allow for a substantial decrease in vehicle drag by modifying the shock properties.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"143 ","pages":"Article 104502"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122565","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":"Simulation of the flow around a tapered ribbon featuring tension-controlled reconfiguration","authors":"Karl Schoppmann ,&nbsp;Bastian Löhrer ,&nbsp;Silvio Tschisgale ,&nbsp;Sophie Ramananarivo ,&nbsp;Jochen Fröhlich","doi":"10.1016/j.jfluidstructs.2025.104493","DOIUrl":"10.1016/j.jfluidstructs.2025.104493","url":null,"abstract":"<div><div>The static reconfiguration of a weighted flexible ribbon of trapezoidal shape, exposed to fluid flow, was investigated by means of highly resolved numerical simulations, configured to match the experiment of Barois and de Langre [J. Fluid Mech. 735, R2, 2013]. Over a broad velocity range, the ribbon experiences a drag force nearly independent of the flow velocity. This phenomenon is regarded as a unique characteristic of tension-controlled reconfiguration, in contrast to the more prevalent case of elastic reconfiguration in literature. The present paper provides a detailed analysis of the flow field in general and the interaction with the ribbon in particular, for example in terms of distributed fluid loads acting on the ribbon. Situations with small and strong reconfiguration of the ribbon reveal fundamentally different wake regimes, hence strongly influencing the characteristics of fluid loading. The findings enabled to develop an enhanced theoretical model in a self-similar framework, especially including a physically justified, realistic local drag coefficient, termed streamline-based local drag model (SLDM). The modeling approach provides an even deeper understanding of the mechanisms during reconfiguration.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"143 ","pages":"Article 104493"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146175410","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 study on hydrodynamics of high-speed water entry in random wave environments for full-scale supercavitating vehicles","authors":"Wen-Tao Liu ,&nbsp;Jing Han ,&nbsp;Qi-Xin Wen ,&nbsp;De-Li Liang ,&nbsp;Yun-Long Liu","doi":"10.1016/j.jfluidstructs.2026.104522","DOIUrl":"10.1016/j.jfluidstructs.2026.104522","url":null,"abstract":"<div><div>The impact load is strongly dependent on wave height and direction during water entry under wave conditions. This study investigates the hydrodynamic characteristics of a full-scale supercavitating vehicle during high-speed water entry under random wave environments. A numerical wave tank (NWT), based on a computational fluid dynamics method, is employed to simulate the water-entry process under such conditions. Additionally, a rapid wave-making method that combines wave theory with boundary wave-making techniques has been developed, and the NWT enables accurate numerical simulations of the high-speed water entry of full-scale vehicles in ocean random waves. Validation is achieved by comparing the average wave height in the numerical results with the target wave height, demonstrating the accuracy of the NWT. The results reveal that the load characteristics and pitching motion of supercavitating vehicles entering water in wave environments exhibit similar trends to those observed during entry into still water. The relative angle of attack during water entry in random wave is identified as a critical factor affecting the pitching motion. As the angle between the vehicle’s motion direction and the wave propagation direction increases, the timing of tail slamming is progressively delayed. However, the maximum impact load associated with tail slamming does not exhibit a linear relationship with this angle.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"143 ","pages":"Article 104522"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146175408","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 physics-based wake-oscillator model of vortex-induced vibrations of circular cylinders","authors":"Issam Bahadur","doi":"10.1016/j.jfluidstructs.2026.104535","DOIUrl":"10.1016/j.jfluidstructs.2026.104535","url":null,"abstract":"<div><div>A new reduced-order model for vortex-induced vibration (VIV) of bluff bodies is developed from the momentum equation of an elastically mounted cylinder. The formulation offers a physical interpretation of its parameters, providing deeper insight into the underlying mechanisms of VIV. In its simplified form, the model reduces to a classical Van der Pol-type wake oscillator, with the lift coefficient expressed as a function of the wake displacement, velocity, and acceleration, <span><math><mrow><msub><mi>C</mi><mi>L</mi></msub><mrow><mo>(</mo><mrow><mi>q</mi><mo>,</mo><mover><mi>q</mi><mi>˙</mi></mover><mo>,</mo><mover><mi>q</mi><mi>̈</mi></mover></mrow><mo>)</mo></mrow></mrow></math></span>. The model’s accuracy is evaluated through validation against experimental and finite element method data for four different mass ratios. Results show that the proposed formulation successfully reproduces key characteristics of VIV, including displacement amplitude, reduced frequency, phase transition, and total lift coefficient, with overall good agreement across all cases. This establishes a robust and physically grounded framework for further exploration of VIV dynamics and stability.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"143 ","pages":"Article 104535"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146175409","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":"Hydrodynamic behaviour of two asymmetrically submerged piezoelectric plates","authors":"Toushik Roy ,&nbsp;Sourav Gupta ,&nbsp;Soumen De ,&nbsp;R. Gayen","doi":"10.1016/j.jfluidstructs.2026.104509","DOIUrl":"10.1016/j.jfluidstructs.2026.104509","url":null,"abstract":"<div><div>In the quest for sustainable and renewable energy sources, use of piezoelectric wave energy converters for harnessing ocean wave energy is becoming increasingly important. However, mathematical modeling of the related problems is somewhat difficult. Thus, in this study we have endeavoured to solve the problem of wave interaction with two unequal vertically submerged piezoelectric plates present in water of uniform finite depth. The piezoelectric nature of the plates gives rise to boundary conditions involving fourth order derivatives with complex coefficients. We have developed a semi-analytical method where this boundary condition is tackled by employing Green’s function technique and the boundary value problem is transformed into a coupled system of integral equations employing a mixed Fourier transform. The integral equations are solved using a Galerkin method to find the reflection and transmission coefficients and the power absorption efficiency of the piezoelectric system. The influence of structural parameters, such as length asymmetry, depth of submergence, spacing and boundary conditions on the scattering coefficients and the efficiency of the plates is systematically examined. Results demonstrate that geometric asymmetry between the plates can significantly enhance energy conversion performance. The findings provide valuable insights for the efficient design and deployment of submerged piezoelectric wave energy converters in real-world marine environments.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104509"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980250","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":"Impact of baffle flexibility on sloshing mitigation: A parametric study using partitioned two-way fluid-structure interaction","authors":"Cristiano Biagioli,&nbsp;Francesco Serraino,&nbsp;Valerio Belardi,&nbsp;Francesco Vivio","doi":"10.1016/j.jfluidstructs.2025.104500","DOIUrl":"10.1016/j.jfluidstructs.2025.104500","url":null,"abstract":"<div><div>This study investigates liquid sloshing in a rectangular tank equipped with horizontal flexible baffles to understand their influence on sloshing mitigation and intricate fluid-structure interaction (FSI) phenomena. A two-way coupled FSI model was developed using the Finite Element Method (FEM) for structural analysis and Finite Volume Method (FVM) with the Volume Of Fluid (VOF) formulation for fluid dynamics, employing a partitioned coupling strategy. Numerical decay tests explored dynamic behavior by varying baffle Young’s modulus and submergence levels. Enstrophy evolution was investigated as a robust indicator for quantifying energy dissipation associated with vortex dynamics, and a reduced-order acoustic-structural model was benchmarked as a tool for predicting fundamental frequency shifts. The FSI simulation methodology was validated against experimental results from previous literature, showing close agreement.</div><div>Key outcomes reveal that baffle stiffness critically governs system response, with appropriate flexibility significantly enhancing damping performance. For submerged baffles, increasing flexibility led to optimal damping driven by maximal vortex-induced energy loss. Conversely, shallow baffles showed superior damping with rigid configurations, primarily due to pressure drag rather than vortex dynamics. While initial conditions introduced transient nonlinearities with flexible baffles, overall trends for damping and frequency remained consistent. The simplified frequency-prediction model was reliable for practical flexibility ranges, but less accurate for extreme flexibility. Overall, this work deepens understanding of how baffle characteristics influence slosh mitigation, offering valuable guidance for anti-sloshing device engineering.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104500"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929240","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 improved WCNS-Z-based ghost-cell immersed boundary method and its application in shock-obstacle interaction simulations","authors":"Huanhuan Yang ,&nbsp;Lin Bi ,&nbsp;Yanqun Jiang","doi":"10.1016/j.jfluidstructs.2026.104517","DOIUrl":"10.1016/j.jfluidstructs.2026.104517","url":null,"abstract":"<div><div>Shock-obstacle interactions (such as shock diffraction, reflection, and vortex shedding) are typical phenomena in high-speed flows. Cartesian grids have become a research focus for studying such flow phenomena due to their automatic generation capability and strong adaptability to complex geometries. However, in shock-complex geometry interactions, the flow near walls undergoes intense variations, making high-fidelity boundary treatment a bottleneck in Cartesian grid numerical simulations. Traditional high-order interpolation tends to generate numerical oscillations in high-gradient regions near solid surfaces, while low-order methods lack sufficient accuracy in smooth flow regions. To address these issues, this paper develops an improved high-order ghost-cell immersed boundary method (GCIBM) based on least-squares high-order polynomial reconstruction. The proposed approach introduces a novel nonlinear weighting function and strictly enforces solid-wall boundary conditions, enabling adaptive blending between first-order (discontinuous regions) and third-order (smooth regions) extrapolation. Additionally, to overcome the accuracy degradation of the classical third-order WCNS-Z scheme at critical points, a modified WCNS-ZM scheme with a new smoothness indicator is proposed, significantly enhancing global accuracy and convergence efficiency. Combined with the high-order ghost-cell immersed boundary method, this approach effectively resolves the conflict between numerical stability and accuracy in shock-obstacle simulations. Numerical experiments on several benchmark cases demonstrate the superiority of the proposed method in capturing strong discontinuities and boundary treatment.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104517"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023838","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":"Symmetry breaking in three-degree-of-freedom flow-induced vibration of the circular cylinder with a splitter plate","authors":"Yue-Hao Sun ,&nbsp;Yu-Ding Qi ,&nbsp;Zhen Chen","doi":"10.1016/j.jfluidstructs.2026.104519","DOIUrl":"10.1016/j.jfluidstructs.2026.104519","url":null,"abstract":"<div><div>This study numerically investigates the three-degree-of-freedom (3-DOF) flow-induced vibration of a circular cylinder with a splitter plate in the laminar flow. Key focus is placed on the competition between the lock-in response and the wake-induced symmetry breaking over a wide range of reduced velocities U* and splitter plate lengths L*. The results reveal that the 3-DOF lock-in response significantly delays the onset of symmetry breaking compared to the 1-DOF flow-induced rotation (FIR) case. This interaction gives rise to the mode competition between the lock-in and the symmetry breaking (CLS) for the first time, which can be further categorized into CLS-I where the lock-in suppresses the symmetry breaking and CLS-II where the two responses coexist. And the temporal evolution of these two competing modes is clearly illustrated using the continuous wavelet transform (CWT). Furthermore, the frequency analysis and the dynamic mode decomposition (DMD) demonstrate that each regime possesses a unique dynamic feature. The lock-in regime is characterized by the main frequency and its third harmonic, while the symmetry breaking state is dominated by the main frequency and the second harmonic. Finally, it is shown that the splitter plate length is a critical parameter that demarcates these regimes. These findings provide a comprehensive map of the structural response and offer new insights into the complex physics of mode competition in the 3-DOF flow induced vibration of the circular cylinder.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104519"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023839","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":"Modeling and computational fluid dynamics validation of a nonholonomically constrained two-rigid-body swimming system","authors":"J. Ardister,&nbsp;J. Geddes,&nbsp;B.F. Feeny,&nbsp;J. Yuan","doi":"10.1016/j.jfluidstructs.2026.104510","DOIUrl":"10.1016/j.jfluidstructs.2026.104510","url":null,"abstract":"<div><div>A simple nonholonomic dynamics model is developed as a low-order model for generating undulatory swim-like motions, validated through computational fluid dynamics (CFD) simulations. The rigid-body-dynamics model generates swimming motion by imposing a nonholonomic (NH) constraint on the tail of a two-body system, requiring that tail-fin velocity aligns with the tail angle, while the head moves in a straight line through a slot constraint. The system has one degree of freedom, with equations of motion derived using Lagrange multipliers. Two-dimensional CFD simulations validate the model in an incompressible Newtonian fluid, where the resolved tail fin interacts with fluid through the immersed boundary method until steady-state swimming is achieved. The validation demonstrates excellent quantitative agreement between CFD and model predictions for body orientation angle and normal fluid force across variations in fin motion amplitude, period, and Reynolds number. While an exact NH constraint point does not exist, an effective period-averaged NH location can be identified for successful model predictions. At higher Reynolds numbers, the two-body kinematics displays independence from the Reynolds number variation. The CFD data reveal that the two-body model captures the type of power-law relationship between Reynolds and Strouhal numbers governing undulatory swimming from tadpoles to whales, indicating that the simplified two-link model is representative of swimming dynamics in continuous geometries at various scales. A key limitation is that the drag force model requires <em>a priori</em> CFD calibration to match steady-swim velocity, limiting standalone predictive capability. The results demonstrate that the low-order NH constraint-based model effectively captures essential swimming dynamics, offering a robust alternative to existing fluid-force models.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104510"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023841","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":"Direct measurements of aerodynamic and inertial contributions to unsteady forces on non-rigid objects in a flow","authors":"F. Paillé ,&nbsp;Y. Haffner ,&nbsp;C. Sicot","doi":"10.1016/j.jfluidstructs.2025.104495","DOIUrl":"10.1016/j.jfluidstructs.2025.104495","url":null,"abstract":"<div><div>A method is presented to separate inertial and aerodynamic contributions to the forces measured in experiments on a non-rigid object in a flow. In particular, it can be used to remove spurious inertial contributions on aerodynamic loads measured with a balance. The method builds on a multiple-input/multiple-output framework and uses conditional spectral analysis in order to provide frequency response functions, or alternatively impulse response functions, to link the inputs quantifying inertia on the object (any kind of acceleration measurements) and the unknown aerodynamic forces on the object to the outputs quantifying total forces on the object (aerodynamic balance or any kind of force measurements). The method provides an efficient way of separating inertial and aerodynamic force contributions on objects in a flow from relatively few acceleration measurements and total force measurements.</div><div>This methodology is assessed on a wall-mounted cylinder in a turbulent boundary layer having two principal bending modes contributing to important inertial forces. It performs well to separate the inertial force contributions of the different bending modes from the pure aerodynamic force contributions which align very closely to the reference aerodynamic pressure forces. Especially, the method allows to separate unambiguously the inertial and aerodynamic force contributions even when structural and aerodynamic resonances have matching frequencies. A second test-case of a model of high-rise building with more complex structural dynamics and less effort put in manufacturing is presented. The method performs also well but with a bit more discrepancies to the reference aerodynamic pressure forces. In this case, part of the inertial forces are not correctly accounted for depending on the relevance of the location and number of acceleration measurements on the object, and on the complexity of the structural dynamics of the object. Leads are provided and discussed to tackle these relative limitations.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"142 ","pages":"Article 104495"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929239","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}