Journal of Fluids and Structures最新文献

{"title":"Performance study of Coriolis mass flowmeter for hydrogen two-phase flow measurement","authors":"Xiangxiang Pei ,&nbsp;Xiaobin Zhang","doi":"10.1016/j.jfluidstructs.2024.104257","DOIUrl":"10.1016/j.jfluidstructs.2024.104257","url":null,"abstract":"<div><div>To enhance the performance of Coriolis mass flowmeters (CMFs) in liquid hydrogen-gas hydrogen (LH₂-GH₂) two-phase flow, we developed a theoretical framework that integrates models of decoupling, finite sound speed, Castiglione's second law, and forced vibration response. This framework was implemented numerically in MATLAB to analyze key parameters, including tube vibration amplitude, measurement error, system quality factor, and the energy dissipation ratio due to tube oscillation and two-phase flow. We first validated the effectiveness of the calculation framework in predicting structural frequencies and displacements using ANSYS. The validated framework was then employed to solve and compare the performance of CMFs under LH₂-GH₂ and water-air conditions across a range of temperatures, emphasizing the challenges posed by the low viscosity, low density, and high compressibility of LH₂. Finally, we investigated the effects of driving force amplitude, tube wall thickness, and tube diameter, proposing strategies to optimize CMF functionality under LH₂-GH₂ conditions. This research addresses gaps in understanding the impact of LH₂-GH₂ on CMF performance and introduces a damping model applicable to tubes of arbitrary shape under two-phase flow. Our findings highlight the unique characteristics of CMF operation in LH₂-GH₂ and lay the groundwork for future technical advancements in this area.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104257"},"PeriodicalIF":3.4,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141307","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":"Uncertainty quantification and sensitivity analysis of the SST turbulence model applied to VIV","authors":"Simone Martini ,&nbsp;Mitja Morgut ,&nbsp;Riccardo Pigazzini ,&nbsp;Lucia Parussini","doi":"10.1016/j.jfluidstructs.2024.104225","DOIUrl":"10.1016/j.jfluidstructs.2024.104225","url":null,"abstract":"<div><div>This paper presents the results of an Uncertainty Quantification and Sensitivity Analysis carried out for the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span> SST turbulence model applied to the bi-dimensional study of Vortex Induced Vibrations of an elastically mounted cylinder. The turbulence model parameters are treated as epistemic uncertain variables and the forward propagation of uncertainty is evaluated using stochastic expansions based on non-intrusive polynomial chaos. The relative contribution of the closure coefficients to the total uncertainty of the output quantities of interest, the non-dimensional amplitude and the frequency ratio, is evaluated using the Sobol indices. The analysis is repeated for different orders of the polynomial chaos expansion. A set of significant coefficients, which contribute most to the uncertainty for this specific case is identified, and furthermore compared with the sets provided for some other selected flow problems in order to gain further insight on the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span> SST turbulence model.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104225"},"PeriodicalIF":3.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141304","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":"Numerical investigations on wake transition of a 2-DOF elastically mounted circular cylinder","authors":"Shristi Singh,&nbsp;Shaligram Tiwari","doi":"10.1016/j.jfluidstructs.2024.104252","DOIUrl":"10.1016/j.jfluidstructs.2024.104252","url":null,"abstract":"<div><div>Present is a three-dimensional (3<em>D</em>) numerical study on vortex-induced vibration (VIV) of an elastically mounted rigid circular cylinder in cross-flow. The cylinder motion has two degrees-of-freedom (2-DOFs), i.e. it can oscillate in both streamwise as well as in transverse directions. The open-source software, ‘OpenFOAM-7′ (Open Field Operation and Manipulation), has been used to solve the governing equations of fluid and cylinder motion. Computations are carried out to investigate the behavior of wake transition from two-dimension to three-dimension (2<em>D</em> to 3<em>D</em>) and the associated flow characteristics over range of values of reduced velocity (<em>U_r</em>), Reynolds number (<em>Re</em>) and mass ratio (<em>m*</em>). In particular, the range of <em>U_r</em> (2 ≤ <em>U_r</em> ≤ 10) encompasses both lock-in and non-lock-in regimes, where lock-in refers to synchronous oscillations of the cylinder and the wake. Effect of <em>U_r</em> on unsteady wake has been examined using vorticity contours and iso-Q surfaces. The temporal behavior of both the cylinder and wake oscillations has been analyzed using Hilbert spectra. The critical value of <em>Re</em> (<span><math><mrow><mi>R</mi><msub><mi>e</mi><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow></math></span>) for transition from 2<em>D</em> to 3<em>D</em> through ‘mode C’ type of instability is ascertained for fixed values of <em>m*</em> and <em>U_r</em>. Thereafter, the critical values of <em>m*</em> and <em>Re</em> are obtained by considering their mutual variation for fixed <em>U_r</em> and the associated mode transition is identified. At small values of <em>m*</em>, ‘mode C’ type of instability appears which changes to ‘mode A’ type for larger <em>m*</em>.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104252"},"PeriodicalIF":3.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141301","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 unsteady aerodynamic reduced-order modelling framework for shock-dominated flow with application on shock-induced panel flutter prediction","authors":"Hao Zhou ,&nbsp;Mingyv Nie ,&nbsp;Mengzhu Qin ,&nbsp;Gang Wang","doi":"10.1016/j.jfluidstructs.2024.104251","DOIUrl":"10.1016/j.jfluidstructs.2024.104251","url":null,"abstract":"<div><div>A fully data-driven unsteady aerodynamic reduced-order modelling framework based on the nonlinear autoregressive with exogenous input structure is established for fluid-structure coupling simulations in the shock dominated flow. A generalized radial basis function neural network extended with polynomials is used for mapping the regressors and model outputs. The training with validation techniques is adopted to enhance the model's generalization ability, and the Bayesian optimization algorithm is selected for hyperparameter tunning. In addition, the fluid-structure coupling is incorporated into the validation process with a modified loss function to improve the robustness of the trained models. Both a generalized aerodynamic force model and a proper orthogonal decomposition based distributed aerodynamic force model are constructed and tested for the prescribed surface motions and fluid-structure coupling simulations. The results show that the constructed models have high accuracy in the forced oscillation tests, and the predicted amplitudes and frequencies of limit cycle oscillations in the shock-induced panel flutter are in excellent agreement with computational fluid dynamics/computational structural dynamics coupling simulations. The statistical results show that the online computational cost of the reduced-order model are orders of magnitude less than that required for the computational fluid dynamics method, indicating the presented modelling framework is an effective tool for the shock dominated aeroelastic problem analysis.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104251"},"PeriodicalIF":3.4,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141303","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":"Investigating stability and dynamics of inverted flags attached to a cylindrical tube","authors":"Sahand Najafpour,&nbsp;Majid Bahrami","doi":"10.1016/j.jfluidstructs.2024.104248","DOIUrl":"10.1016/j.jfluidstructs.2024.104248","url":null,"abstract":"<div><div>Inverted flags have captivated the attention of researchers due to their distinct behavior and post-divergence dynamics. In this study, we focused on the instability and post-divergence dynamics of an inverted flag attached to a tube in a flow impinging on its free end. A new model is proposed which captures the instability of an arbitrary aspect-ratio inverted flag attached to a tube and is validated with experimental data collected in our lab. An asymptotic approach is adopted to cover a wide range of aspect ratios and tube radius to flag length ratios. Generally, the tube increases the critical flow speed by decelerating the flow speed in the vicinity of the flag. Our experimental measurements also showed the flapping frequency increases and reaches a maximum value with increasing flow speed for the case where the tube is absent. However, the frequency remained relatively constant at the onset of flapping or declined consistently for a flag affixed to a tube. Additionally, an earlier transition to the fully deflected mode was observed in the presence of a tube.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104248"},"PeriodicalIF":3.4,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141265","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":"Role of turbulence on high-speed aeroelastic behavior of a cantilever plate","authors":"Jordan D. Thayer ,&nbsp;Matthew J. Kronheimer ,&nbsp;Rohit Deshmukh ,&nbsp;Jack J. McNamara ,&nbsp;Datta V. Gaitonde","doi":"10.1016/j.jfluidstructs.2024.104231","DOIUrl":"10.1016/j.jfluidstructs.2024.104231","url":null,"abstract":"<div><div>Accurate and efficient prediction of high-speed aeroelastic behavior is greatly hampered by insufficient understanding of the role of multi-scale fluid features on structural dynamics. In this work, we use a combination of scale-resolving and modeled simulations to evaluate the significance of capturing coupling with the broadband turbulent pressure fluctuations on prediction of the aeroelastic response. A Mach 2 turbulent flow separating from a cantilever plate is considered at nondimensional dynamic pressures of <span><math><mrow><mi>λ</mi><mo>=</mo><mn>100</mn></mrow></math></span> and 150. The fully coupled Large-Eddy Simulations (LES) predict sustained oscillations, with larger amplitudes and modal coalescence for the higher <span><math><mi>λ</mi></math></span> and shock-induced separation on the cantilever top surface. The significance of capturing dynamic feedback between the broadband turbulence and structural compliance is highlighted through aeroelastic response prediction comparisons between LES and URANS. Here, wall pressure fluctuations are extracted from LES data about undeformed and time-mean deflected states of the cantilever and separately added to coupled URANS simulations. The results indicate that key aspects of the aeroelastic behavior can be recovered by URANS in conjunction with an uncoupled turbulent load. However, clear differences in response frequency and instantaneous amplitude remain present compared to LES, suggesting missing coupled phenomena from the URANS prediction.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104231"},"PeriodicalIF":3.4,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141311","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 comprehensive numerical study on the current-induced fluid–structure interaction of flexible submerged vegetation","authors":"Inga Prüter ,&nbsp;Felix Spröer ,&nbsp;Kara Keimer ,&nbsp;Oliver Lojek ,&nbsp;Christian Windt ,&nbsp;David Schürenkamp ,&nbsp;Hans Bihs ,&nbsp;Ioan Nistor ,&nbsp;Nils Goseberg","doi":"10.1016/j.jfluidstructs.2024.104232","DOIUrl":"10.1016/j.jfluidstructs.2024.104232","url":null,"abstract":"<div><div>Submerged vegetation is becoming more and more relevant as a nature-based solution for coastal protection schemes, counteracting the effects of climate change and sea level rise. The numerical model REEF3D has been used to simulate the motion of and forces exerted on flexible vegetation under unidirectional currents. This study emphasizes the critical need for accurate solutions obtained by numerical models to investigate the complex ecosystem services, adopting a direct forcing approach using the immersed boundary method. The fluid–structure interaction capability within the finite difference model is comprehensively evaluated for the simulation of stem motions and forces exerted on flexible vegetation under varying unidirectional flows. Thresholds for numerical parameters, including a minimum number of 25 rigid elements composing the stem, are identified for accurate solutions. The necessity of using large eddy simulations and a Smagorinsky constant of 0.1 to simulate the turbulent flow is demonstrated. The study confirms the accuracy of the implemented fluid–structure interaction model to replicate stem bending (less than 10<!--> <!-->% deviation relative to the stem length) and forces across varying hydrodynamic conditions.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104232"},"PeriodicalIF":3.4,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141302","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":"Experimental study on vortex-induced vibrations of a circular cylinder elastically supported by realistic nonlinear springs: Vibration response","authors":"Yawei Zhao ,&nbsp;Zhimeng Zhang ,&nbsp;Chunning Ji ,&nbsp;Weilin Chen ,&nbsp;Jiahang Lv ,&nbsp;Hanghao Zhao","doi":"10.1016/j.jfluidstructs.2024.104233","DOIUrl":"10.1016/j.jfluidstructs.2024.104233","url":null,"abstract":"<div><div>This study presents an experimental investigation into the vortex-induced vibrations (VIV) of a single circular cylinder supported by various nonlinear springs. Unlike previous studies focused on systems satisfying the Duffing equation, this study explores a realistic scenario with nonlinear restoring forces derived from different magnet configurations. Experiments were conducted in a low-speed circulating water flume across a Reynolds number range of <em>Re</em> = 232-20930, a mass ratio (<em>m*</em>) ranging from 3.39 to 5.55, and a nonlinear strength coefficient (<em>λ</em>) from -1.48 to 1.70. The results demonstrated that predicted nonlinear VIV amplitudes using linear VIV data align well with experimental observations, validating the applicability of the prediction theory (Mackowski and Williamson, PoF, 2013) to general nonlinear systems. An equivalent reduced velocity (<em>U_eq</em>) was introduced to rescale vibration responses, effectively collapsing the envelopes for linear and hardening nonlinear systems, although shifts to higher <em>U_eq</em> values were observed for softening systems. A detailed analysis of the nonlinear coefficient's impact on VIV characteristics, including amplitude, frequency, phase lag, and displacement history, identified four distinct VIV response groups: softening, weak hardening, intermediate hardening, and strong hardening nonlinear VIV. A notable finding is the presence of two lock-in regions in nonlinear VIV responses, characterized by superharmonic synchronization, and multiple-value sections and gaps in vibration envelopes at specific transitions. These behaviors are attributed to variations in the natural frequency (<em>f_n</em>(<em>A*</em>)) with vibration amplitude. This study provides valuable insights into the complex dynamics of general nonlinear VIV, offering a foundation for future research and practical applications.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104233"},"PeriodicalIF":3.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759307","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":"Editorial for the “Special Issue in Honor of Emmanuel de Langre”","authors":"Yahya Modarres-Sadeghi","doi":"10.1016/j.jfluidstructs.2024.104223","DOIUrl":"10.1016/j.jfluidstructs.2024.104223","url":null,"abstract":"","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104223"},"PeriodicalIF":3.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136244","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 mechanism of frequency lock-in vibration of airfoils during pre-stall conditions","authors":"Jingge Quan ,&nbsp;Sijia Zhang ,&nbsp;Chuanqiang Gao ,&nbsp;Zhengyin Ye ,&nbsp;Weiwei Zhang","doi":"10.1016/j.jfluidstructs.2024.104227","DOIUrl":"10.1016/j.jfluidstructs.2024.104227","url":null,"abstract":"<div><div>Potential frequency lock-in vibration can frequently occur in aircraft flying at separated flow conditions during take-off and landing stages, severely threatening the safety of the aircraft. A deeper understanding of the lock-in phenomenon in pre-stall (steady separated flow) conditions is necessary to improve aircraft reliability and safety. In this paper, a reduced-order model (ROM) for the pitching NACA0012 airfoil in steady separated flow is established. A linear aeroelastic model is then obtained by coupling the ROM with the structural dynamical equation with the pitching degree of freedom, and it is verified by the computational fluid dynamics/computational structural dynamics (CFD/CSD) simulation. Next, the mechanism of frequency lock-in vibration is revealed by the ROM-based aeroelastic model of different structural natural frequencies. Results from the complex eigenvalue analysis indicate that the instability can be divided into two patterns. At high frequencies, the flutter frequency locked onto the natural frequency of the structure, and it is dominated by the instability of structural mode. At low frequencies, the flutter frequency follows the fluid characteristic frequency, which is dominated by the instability of the fluid mode. Finally, the effects of the angle of attack and mass ratio are investigated. The damping of dominant fluid mode decreases with the increase of angle of attack, which affects the structural mode through coupling effects. Therefore, the angle of attack influences the upper boundary of the coupling system’s instability (high frequency boundary). On the contrary, the mass ratio mainly influences the lower boundary of instability (low frequency boundary), because fluid mode becomes unstable at low frequencies merely when the mass ratio is relatively low.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"133 ","pages":"Article 104227"},"PeriodicalIF":3.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759302","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}