Pub Date : 2024-11-16DOI: 10.1016/j.jfluidstructs.2024.104219
Erik García Neefjes , David Nigro , Raphaël C. Assier , William J. Parnell
In this paper, we theoretically analyse wave propagation in two canonical problems of interest: fluid-filled thermo-visco-elastic slits and fluid-loaded thermo-visco-elastic plates. We show that these two configurations can be studied via the same pair of dispersion equations with the aid of the framework developed in García Neefjes et al. (2022), which incorporates thermal effects. These two problems are further interrelated, since in the short wavelength limit (relative to the slit/plate width) the respective modes are governed by the same dispersion equation, commonly known as the Scholte–Stoneley equation. It is the Scholte-type modes that are mainly analysed in this paper. We illustrate results when the fluid is water, although the theory is valid for any Newtonian fluid. Both ‘hard’ and ‘soft’ solids are compared, with the emphasis being placed on the importance of thermo-viscoelastic effects, particularly when stress relaxation is considered. Two main recent works are discussed extensively, namely (Cotterill et al., 2018) for slits and (Staples et al., 2021) for loaded plates, both of which do not incorporate viscoelastic mechanisms. We show how the consideration of viscoelasticity can extend the results discussed therein, and explain the circumstances under which they arise.
{"title":"Stress relaxation and thermo-visco-elastic effects in fluid-filled slits and fluid-loaded plates","authors":"Erik García Neefjes , David Nigro , Raphaël C. Assier , William J. Parnell","doi":"10.1016/j.jfluidstructs.2024.104219","DOIUrl":"10.1016/j.jfluidstructs.2024.104219","url":null,"abstract":"<div><div>In this paper, we theoretically analyse wave propagation in two canonical problems of interest: fluid-filled thermo-visco-elastic slits and fluid-loaded thermo-visco-elastic plates. We show that these two configurations can be studied via the same pair of dispersion equations with the aid of the framework developed in García Neefjes et al. (2022), which incorporates thermal effects. These two problems are further interrelated, since in the short wavelength limit (relative to the slit/plate width) the respective modes are governed by the same dispersion equation, commonly known as the Scholte–Stoneley equation. It is the Scholte-type modes that are mainly analysed in this paper. We illustrate results when the fluid is water, although the theory is valid for any Newtonian fluid. Both ‘hard’ and ‘soft’ solids are compared, with the emphasis being placed on the importance of thermo-viscoelastic effects, particularly when <em>stress relaxation</em> is considered. Two main recent works are discussed extensively, namely (Cotterill et al., 2018) for slits and (Staples et al., 2021) for loaded plates, both of which do not incorporate viscoelastic mechanisms. We show how the consideration of viscoelasticity can extend the results discussed therein, and explain the circumstances under which they arise.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104219"},"PeriodicalIF":3.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658839","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}
Pub Date : 2024-11-14DOI: 10.1016/j.jfluidstructs.2024.104215
Yan Naung Aye, Narakorn Srinil
This study presents an advanced numerical model for predicting a two-dimensional coupled galloping and vortex-induced vibration (VIV) in cross-flow and in-line directions of square cylinders under symmetric and asymmetric flow orientations. The present model combines the quasi-steady theory for the galloping with the nonlinear structure-wake oscillators simulating VIV, capturing the time-varying drag and lift hydrodynamic forces with the time-averaged and fluctuating components. By placing a flexibly mounted square cylinder in uniform flow at an initial angle of incidence, the cylinder is subject to instantaneous changes in the dynamic angle of attack accounting for relative flow-structure velocities. Modelling of such features in cross-flow and in-line directions for low and high mass ratio systems extends previous studies which have mostly focused on cross-flow responses of square cylinders with high mass ratios at a zero angle of incidence. New sets of empirical coefficients governing the drag and lift fluid forces for both the quasi-steady and wake oscillator approaches are introduced by calibrating with available experimental data in the literature, applicable to predict several flow-induced vibration phenomena under arbitrary flow-structure orientations. Mathematical criteria for the onset of two- and one-dimensional galloping instability are presented, verifying the likelihood of galloping occurrence. Parametric investigations are carried out to highlight the important effects of flow incidence angle, mass-damping ratio (Scruton number) and in-line response on the prediction of galloping and VIV in comparison with experimental results. By varying the reduced velocity parameter, the present model captures key qualitative features of the dominant galloping, interfering galloping-VIV and dominant VIV through the response amplitudes, mean drift displacements, oscillation frequencies, fluid force components and motion trajectories. Contributions from in-line responses are found to be meaningful for the interfering galloping-VIV system with a low mass-damping ratio and for an asymmetric flow orientation. The present model could be further calibrated and applied to other fluid-structure interaction applications with non-circular cross-sectional geometries under omnidirectional flow directions.
{"title":"Numerical Prediction of Two-Dimensional Coupled Galloping and Vortex-Induced Vibration of Square Cylinders Under Symmetric/Asymmetric Flow Orientations","authors":"Yan Naung Aye, Narakorn Srinil","doi":"10.1016/j.jfluidstructs.2024.104215","DOIUrl":"10.1016/j.jfluidstructs.2024.104215","url":null,"abstract":"<div><div>This study presents an advanced numerical model for predicting a two-dimensional coupled galloping and vortex-induced vibration (VIV) in cross-flow and in-line directions of square cylinders under symmetric and asymmetric flow orientations. The present model combines the quasi-steady theory for the galloping with the nonlinear structure-wake oscillators simulating VIV, capturing the time-varying drag and lift hydrodynamic forces with the time-averaged and fluctuating components. By placing a flexibly mounted square cylinder in uniform flow at an initial angle of incidence, the cylinder is subject to instantaneous changes in the dynamic angle of attack accounting for relative flow-structure velocities. Modelling of such features in cross-flow and in-line directions for low and high mass ratio systems extends previous studies which have mostly focused on cross-flow responses of square cylinders with high mass ratios at a zero angle of incidence. New sets of empirical coefficients governing the drag and lift fluid forces for both the quasi-steady and wake oscillator approaches are introduced by calibrating with available experimental data in the literature, applicable to predict several flow-induced vibration phenomena under arbitrary flow-structure orientations. Mathematical criteria for the onset of two- and one-dimensional galloping instability are presented, verifying the likelihood of galloping occurrence. Parametric investigations are carried out to highlight the important effects of flow incidence angle, mass-damping ratio (Scruton number) and in-line response on the prediction of galloping and VIV in comparison with experimental results. By varying the reduced velocity parameter, the present model captures key qualitative features of the dominant galloping, interfering galloping-VIV and dominant VIV through the response amplitudes, mean drift displacements, oscillation frequencies, fluid force components and motion trajectories. Contributions from in-line responses are found to be meaningful for the interfering galloping-VIV system with a low mass-damping ratio and for an asymmetric flow orientation. The present model could be further calibrated and applied to other fluid-structure interaction applications with non-circular cross-sectional geometries under omnidirectional flow directions.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104215"},"PeriodicalIF":3.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658838","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}
Pub Date : 2024-11-13DOI: 10.1016/j.jfluidstructs.2024.104217
S. Liang, Y. Gou, B. Teng
The nonlinear interaction between nonlinear waves and a three-dimensional floating elastic plate is simulated by a time-domain nonlinear potential flow model. On the free surface, the 4th-order Runge-Kutta scheme with a semi-Lagrangian approach is adopted in the time-stepping process. The classical thin-plate theory is selected to simulate the motion of the elastic plate. The higher-order boundary element method (HOBEM) is employed to solve the corresponding boundary value problem at each time step. After validation of the present model, a particular frequency phenomenon is successfully observed in a three-dimensional hydroelastic problem, which shows that the second harmonic displacements at the centre point of the upwave side and downwave side of the elastic plate near a particular frequency are significantly large. In addition, the effect of the plate width on the particular frequency phenomenon is discussed.
{"title":"A three-dimensional nonlinear hydroelastic model for rectangular floating elastic plates and the examination on the peak frequency with maximum nonlinear response","authors":"S. Liang, Y. Gou, B. Teng","doi":"10.1016/j.jfluidstructs.2024.104217","DOIUrl":"10.1016/j.jfluidstructs.2024.104217","url":null,"abstract":"<div><div>The nonlinear interaction between nonlinear waves and a three-dimensional floating elastic plate is simulated by a time-domain nonlinear potential flow model. On the free surface, the 4th-order Runge-Kutta scheme with a semi-Lagrangian approach is adopted in the time-stepping process. The classical thin-plate theory is selected to simulate the motion of the elastic plate. The higher-order boundary element method (HOBEM) is employed to solve the corresponding boundary value problem at each time step. After validation of the present model, a particular frequency phenomenon is successfully observed in a three-dimensional hydroelastic problem, which shows that the second harmonic displacements at the centre point of the upwave side and downwave side of the elastic plate near a particular frequency are significantly large. In addition, the effect of the plate width on the particular frequency phenomenon is discussed.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104217"},"PeriodicalIF":3.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658834","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}
Pub Date : 2024-11-12DOI: 10.1016/j.jfluidstructs.2024.104218
Xu Wang , Jiazhen Zhao , Xianzhong Tan , Chao Qi , Aochen Zhao , He Li , Ruisheng Sun , Xujian Lyu
A three-dimensional numerical model with six-degree-of-freedom is developed to simulate the side-by-side entry of twin spheres into flowing water. With the explicit volume of fluid (VOF) approach, the shear-stress transport (SST) k-ω model is adopted to delineate the turbulence structures within the flow, while the independent movements of the two spheres are tracked using advanced multi-overset mesh technology. The numerical findings elucidate the effects of water flow on cavity dynamics, flow field evolution, forces, and trajectories during consecutive sphere entries. Distinct flow field characteristics emerge depending on whether the trailing sphere enters the upstream side or downstream side. The flow-induced tilting of the first cavity results in a different scale of expansion of the trailing cavity with respect to that in quiescent water, diminishing the attractive force on the upstream-side sphere and enhancing it for the downstream-side sphere. As the lateral distance between the spheres increases, the forces of attraction and repulsion generated by the leading cavity become marginal in their effect on the trailing sphere's trajectory, particularly when compared with the impact force of the water flow.
{"title":"Numerical study of consecutive water entries in flowing water with twin spheres side-by-side","authors":"Xu Wang , Jiazhen Zhao , Xianzhong Tan , Chao Qi , Aochen Zhao , He Li , Ruisheng Sun , Xujian Lyu","doi":"10.1016/j.jfluidstructs.2024.104218","DOIUrl":"10.1016/j.jfluidstructs.2024.104218","url":null,"abstract":"<div><div>A three-dimensional numerical model with six-degree-of-freedom is developed to simulate the side-by-side entry of twin spheres into flowing water. With the explicit volume of fluid (VOF) approach, the shear-stress transport (SST) <em>k-ω</em> model is adopted to delineate the turbulence structures within the flow, while the independent movements of the two spheres are tracked using advanced multi-overset mesh technology. The numerical findings elucidate the effects of water flow on cavity dynamics, flow field evolution, forces, and trajectories during consecutive sphere entries. Distinct flow field characteristics emerge depending on whether the trailing sphere enters the upstream side or downstream side. The flow-induced tilting of the first cavity results in a different scale of expansion of the trailing cavity with respect to that in quiescent water, diminishing the attractive force on the upstream-side sphere and enhancing it for the downstream-side sphere. As the lateral distance between the spheres increases, the forces of attraction and repulsion generated by the leading cavity become marginal in their effect on the trailing sphere's trajectory, particularly when compared with the impact force of the water flow.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104218"},"PeriodicalIF":3.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658833","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}
Pub Date : 2024-11-02DOI: 10.1016/j.jfluidstructs.2024.104200
Farrukh Mazhar, Ali Javed
Partitioned fluid–solid interaction (FSI) problems involving non-conforming grids pose formidable challenge in interface treatment, especially for information exchange, interface tracking, and field variable interpolation between solvers in both space and time. These demand special considerations for accurate and efficient simulations. This paper presents an application of artificial neural networks (ANN) for the interface treatment in a coupled FSI problem employing partitioned solvers. A shallow time-series ANN (nonlinear auto-regressive model with exogenous inputs, NARX) scheme is proposed to handle the exchange of Neumann/Dirichlet information at the coupling interface. This scheme involves two interface treatment models that were developed and analysed. The proposed models interpolate and transfer loads from the fluid to the solid domains, and conversely, displacements from the solid to the fluid domains between non-collocated grids. To validate this approach, we tested it on a 3D FSI problem, which involved damped oscillations of a flexible flap submerged in a fluid cavity. Adequately trained NARX interface models demonstrate reliable input–output mapping and accurate prediction of transient behaviour at the interface. Additionally, we explored the concept of reduced-order modelling (ROM) in the time domain. This allowed us to reduce the model’s complexity by half. Different training algorithms were evaluated to enhance the efficiency and performance of the proposed scheme. The study demonstrates that NARX networks trained with Bayesian Regularization (BR) and Levenberg–Marquardt (LM) algorithms exhibit the best accuracy, while the scaled conjugate gradient (SCG)-based training method provides better computational efficiency with acceptable accuracy. Overall, the NARX interface models provide precise performance and offer a viable potential for applications in FSI problems requiring accurate and faster computations.
{"title":"A new approach for spatio-temporal interface treatment in fluid–solid interaction using artificial neural networks employing coupled partitioned fluid–solid solvers","authors":"Farrukh Mazhar, Ali Javed","doi":"10.1016/j.jfluidstructs.2024.104200","DOIUrl":"10.1016/j.jfluidstructs.2024.104200","url":null,"abstract":"<div><div>Partitioned fluid–solid interaction (FSI) problems involving non-conforming grids pose formidable challenge in interface treatment, especially for information exchange, interface tracking, and field variable interpolation between solvers in both space and time. These demand special considerations for accurate and efficient simulations. This paper presents an application of artificial neural networks (ANN) for the interface treatment in a coupled FSI problem employing partitioned solvers. A shallow time-series ANN (nonlinear auto-regressive model with exogenous inputs, NARX) scheme is proposed to handle the exchange of Neumann/Dirichlet information at the coupling interface. This scheme involves two interface treatment models that were developed and analysed. The proposed models interpolate and transfer loads from the fluid to the solid domains, and conversely, displacements from the solid to the fluid domains between non-collocated grids. To validate this approach, we tested it on a 3D FSI problem, which involved damped oscillations of a flexible flap submerged in a fluid cavity. Adequately trained NARX interface models demonstrate reliable input–output mapping and accurate prediction of transient behaviour at the interface. Additionally, we explored the concept of reduced-order modelling (ROM) in the time domain. This allowed us to reduce the model’s complexity by half. Different training algorithms were evaluated to enhance the efficiency and performance of the proposed scheme. The study demonstrates that NARX networks trained with Bayesian Regularization (BR) and Levenberg–Marquardt (LM) algorithms exhibit the best accuracy, while the scaled conjugate gradient (SCG)-based training method provides better computational efficiency with acceptable accuracy. Overall, the NARX interface models provide precise performance and offer a viable potential for applications in FSI problems requiring accurate and faster computations.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104200"},"PeriodicalIF":3.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571756","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}
Pub Date : 2024-11-01DOI: 10.1016/j.jfluidstructs.2024.104214
Yu Hu , Zhiguang Song , Erasmo Carrera
In the fluid-structure dynamic analysis, the low solution efficiency seriously restricts the passive and active vibration control of structures. But so far, this issue has not been well addressed. Component mode synthesis (CMS) is an efficient method for dynamic analysis of structures. However, since the concept of mode for the fluid is very weak, the CMS is not suitable for solving fluid-structure interaction dynamic problems. Another type of dimension reduction method is dynamic condensation originating from Guyan method. In this paper, introducing the idea of CMS and combining the Guyan method, an efficient condensation solution method is proposed to solve the fluid-structure interaction dynamic models. In the dynamical modeling, both the structure field and fluid field are discretized using 20-node three dimensional elements. The elemental fluid-structure interaction equations of motion are formulated using the Hamilton principle and weighted residual method. The solid and fluid fields are divided into substructures, and all the degrees of freedom (DOFs) of the two fields are divided into interior structure DOFs, boundary structure DOFs, interior master fluid DOFs, interior salve fluid DOFs, as well as boundary fluid DOFs. In the solid substructures, higher orders of mode are neglected to realize a large-scale dimensional reduction, while for the fluid field, the slave DOFs are replaced by the master DOFs. To conduct the verification of the present method, experiment is carried out. The comparison results show the high accuracy and efficiency of the condensation solution method.
{"title":"Condensation solution method for fluid-structure interaction dynamic models of structural system","authors":"Yu Hu , Zhiguang Song , Erasmo Carrera","doi":"10.1016/j.jfluidstructs.2024.104214","DOIUrl":"10.1016/j.jfluidstructs.2024.104214","url":null,"abstract":"<div><div>In the fluid-structure dynamic analysis, the low solution efficiency seriously restricts the passive and active vibration control of structures. But so far, this issue has not been well addressed. Component mode synthesis (CMS) is an efficient method for dynamic analysis of structures. However, since the concept of mode for the fluid is very weak, the CMS is not suitable for solving fluid-structure interaction dynamic problems. Another type of dimension reduction method is dynamic condensation originating from Guyan method. In this paper, introducing the idea of CMS and combining the Guyan method, an efficient condensation solution method is proposed to solve the fluid-structure interaction dynamic models. In the dynamical modeling, both the structure field and fluid field are discretized using 20-node three dimensional elements. The elemental fluid-structure interaction equations of motion are formulated using the Hamilton principle and weighted residual method. The solid and fluid fields are divided into substructures, and all the degrees of freedom (DOFs) of the two fields are divided into interior structure DOFs, boundary structure DOFs, interior master fluid DOFs, interior salve fluid DOFs, as well as boundary fluid DOFs. In the solid substructures, higher orders of mode are neglected to realize a large-scale dimensional reduction, while for the fluid field, the slave DOFs are replaced by the master DOFs. To conduct the verification of the present method, experiment is carried out. The comparison results show the high accuracy and efficiency of the condensation solution method.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104214"},"PeriodicalIF":3.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571754","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}
This study investigates the fluid–structure interaction of two coaxial cylinders separated by a Newtonian fluid under turbulent axial flow. The theoretical framework treats the inner cylinder as a rigid body mounted on a flexible blade modeled as a Rayleigh beam. The goals of this study are to determine the free vibration modes and frequencies, identify the fluid-elastic instability threshold, and establish an analytical expression for the mean-square displacement of the structure. The approach integrates various fluid forces and torques, such as Archimedean thrust, fluid-elastic forces for a quiescent fluid, fluid-elastic forces due to flow, and the effects of fluid turbulence. The new approach reveals that vibration modes, frequencies, instability thresholds, and mean-square displacement each depend on a different set of dimensionless parameters: 8, 11, and 12, respectively. These parameters include the cylinder aspect ratio and fluid gap radius ratio. By incorporating models from the literature for viscous friction coefficients, turbulent pressure power spectral density, and coherence function, the study demonstrates stability conditions and the scaling of mean-square displacement with Reynolds number squared. The study, presented in a fully dimensionless formulation, aims to assist engineers in constructing small-scale experiments representative of pressure vessel vibrations. To facilitate this, a Python code for system stability determination and mean-square displacement calculation is provided.
{"title":"Turbulence-induced vibration in annular flow of a rigid cylinder mounted on a cantilever beam","authors":"Romain Lagrange , Loucas Plado Costante , Maud Kocher","doi":"10.1016/j.jfluidstructs.2024.104213","DOIUrl":"10.1016/j.jfluidstructs.2024.104213","url":null,"abstract":"<div><div>This study investigates the fluid–structure interaction of two coaxial cylinders separated by a Newtonian fluid under turbulent axial flow. The theoretical framework treats the inner cylinder as a rigid body mounted on a flexible blade modeled as a Rayleigh beam. The goals of this study are to determine the free vibration modes and frequencies, identify the fluid-elastic instability threshold, and establish an analytical expression for the mean-square displacement of the structure. The approach integrates various fluid forces and torques, such as Archimedean thrust, fluid-elastic forces for a quiescent fluid, fluid-elastic forces due to flow, and the effects of fluid turbulence. The new approach reveals that vibration modes, frequencies, instability thresholds, and mean-square displacement each depend on a different set of dimensionless parameters: 8, 11, and 12, respectively. These parameters include the cylinder aspect ratio and fluid gap radius ratio. By incorporating models from the literature for viscous friction coefficients, turbulent pressure power spectral density, and coherence function, the study demonstrates stability conditions and the scaling of mean-square displacement with Reynolds number squared. The study, presented in a fully dimensionless formulation, aims to assist engineers in constructing small-scale experiments representative of pressure vessel vibrations. To facilitate this, a Python code for system stability determination and mean-square displacement calculation is provided.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104213"},"PeriodicalIF":3.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571755","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}
Pub Date : 2024-10-28DOI: 10.1016/j.jfluidstructs.2024.104202
David Massegur , Andrea Da Ronch
Unsteady, high-fidelity aerodynamic load predictions around a three-dimensional configuration will remain computationally expensive for the foreseeable future. Data-driven algorithms based on deep-learning are an attractive option for reduced order modelling of complex, nonlinear systems. However, a dedicated approach is needed for applicability to large and unstructured domains that are typical in engineering. This work presents a geometric-deep-learning multi-mesh autoencoder framework to predict the spatial and temporal evolution of aerodynamic loads for a finite-span wing undergoing different types of motion. The novel framework leverages on: (a) graph neural networks for aerodynamic surface grids embedded with a multi-resolution algorithm for dimensionality reduction; and (b) a recurrent scheme for time-marching the aerodynamic loads. The test case is for the BSCW wing in transonic flow undergoing a combination of forced-motions in pitch and plunge. A comprehensive comparison between a quasi-steady and a recurrent approach is provided. The model training requires four unsteady, high-fidelity aerodynamic analyses which require each about two days of HPC computing time. For any common engineering task that involves more than four cases, a clear benefit in computing costs is achieved using the proposed framework as an alternative predictive tool: new cases are computed in seconds on a standard GPU.
{"title":"Recurrent graph convolutional multi-mesh autoencoder for unsteady transonic aerodynamics","authors":"David Massegur , Andrea Da Ronch","doi":"10.1016/j.jfluidstructs.2024.104202","DOIUrl":"10.1016/j.jfluidstructs.2024.104202","url":null,"abstract":"<div><div>Unsteady, high-fidelity aerodynamic load predictions around a three-dimensional configuration will remain computationally expensive for the foreseeable future. Data-driven algorithms based on deep-learning are an attractive option for reduced order modelling of complex, nonlinear systems. However, a dedicated approach is needed for applicability to large and unstructured domains that are typical in engineering. This work presents a geometric-deep-learning multi-mesh autoencoder framework to predict the spatial and temporal evolution of aerodynamic loads for a finite-span wing undergoing different types of motion. The novel framework leverages on: (a) graph neural networks for aerodynamic surface grids embedded with a multi-resolution algorithm for dimensionality reduction; and (b) a recurrent scheme for time-marching the aerodynamic loads. The test case is for the BSCW wing in transonic flow undergoing a combination of forced-motions in pitch and plunge. A comprehensive comparison between a quasi-steady and a recurrent approach is provided. The model training requires four unsteady, high-fidelity aerodynamic analyses which require each about two days of HPC computing time. For any common engineering task that involves more than four cases, a clear benefit in computing costs is achieved using the proposed framework as an alternative predictive tool: new cases are computed in seconds on a standard GPU.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104202"},"PeriodicalIF":3.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530946","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}
Pub Date : 2024-10-28DOI: 10.1016/j.jfluidstructs.2024.104206
Hao Ding , Jian Song , Xiaojun Fang
The tuned liquid column damper (TLCD) operates as a fluid counterpart to a tuned mass damper (TMD), harnessing the dynamics of liquid flow to effectively counteract unwanted vibrations, thereby achieving the stability within the structural system. Most recently, to overcome the shortcoming that conventional TLCDs can only control the vibration of structures in a single direction, a toroidal tuned liquid multi-column damper (TLMCD) was proposed and its control effectiveness was preliminarily validated. However, the hydrodynamic characteristics of the TLMCD remain elusive and warrant further clarification. Therefore, this study employs computational fluid dynamics (CFD) methodology to meticulously simulate the intricate three-dimensional multiphase flow dynamics within toroidal TLMCDs across a spectrum of excitation conditions, aiming to elucidate their hydrodynamic behaviors. The efficacy of the CFD-based simulation approach is validated through a comparative analysis of numerically computed and experimentally measured liquid displacement responses. The error magnitude of the simplified theoretical model for toroidal TLMCDs is assessed by comparing the outcomes derived from CFD simulations with the theoretical predictions. Furthermore, by visualizing the spatial and temporal distribution of fluid flow field, the three-dimensional fluid flow properties of toroidal TLMCDs are characterized. The findings presented highlight the frequency-dependent nonlinear characteristics of liquid column oscillatory responses, providing a valuable benchmark for the development of more refined theoretical models and guiding the optimization of fluid-type dampers.
{"title":"On the characteristics of fluid flow field and oscillatory response of tuned liquid multi-column dampers","authors":"Hao Ding , Jian Song , Xiaojun Fang","doi":"10.1016/j.jfluidstructs.2024.104206","DOIUrl":"10.1016/j.jfluidstructs.2024.104206","url":null,"abstract":"<div><div>The tuned liquid column damper (TLCD) operates as a fluid counterpart to a tuned mass damper (TMD), harnessing the dynamics of liquid flow to effectively counteract unwanted vibrations, thereby achieving the stability within the structural system. Most recently, to overcome the shortcoming that conventional TLCDs can only control the vibration of structures in a single direction, a toroidal tuned liquid multi-column damper (TLMCD) was proposed and its control effectiveness was preliminarily validated. However, the hydrodynamic characteristics of the TLMCD remain elusive and warrant further clarification. Therefore, this study employs computational fluid dynamics (CFD) methodology to meticulously simulate the intricate three-dimensional multiphase flow dynamics within toroidal TLMCDs across a spectrum of excitation conditions, aiming to elucidate their hydrodynamic behaviors. The efficacy of the CFD-based simulation approach is validated through a comparative analysis of numerically computed and experimentally measured liquid displacement responses. The error magnitude of the simplified theoretical model for toroidal TLMCDs is assessed by comparing the outcomes derived from CFD simulations with the theoretical predictions. Furthermore, by visualizing the spatial and temporal distribution of fluid flow field, the three-dimensional fluid flow properties of toroidal TLMCDs are characterized. The findings presented highlight the frequency-dependent nonlinear characteristics of liquid column oscillatory responses, providing a valuable benchmark for the development of more refined theoretical models and guiding the optimization of fluid-type dampers.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104206"},"PeriodicalIF":3.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530947","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}
Pub Date : 2024-10-19DOI: 10.1016/j.jfluidstructs.2024.104205
Wenbin Ye , Lei Gan , Haibo Wang , Quansheng Zang , Lei Qin , Jun Liu
In this paper, a novel semi-analytical approach is proposed for the three-dimensional fluid-structure coupling analysis of liquid sloshing in elastic containers subjected to harmonic and seismic loading in the horizontal direction, based on the scaled boundary finite element method (SBFEM). A modified SBFEM model, referred to as the scaling surface-based SBFEM, is developed to simulate the container wall, which is treated as a thin shell structure. Within the framework of the scaling surface-based SBFEM, the geometry of the shell structure is entirely determined by scaling one surface of the structure. This approach differs significantly from the standard SBFEM, where approximation is achieved through coordinate mapping based on a scaling center, thereby enhancing the modeling accuracy and efficiency. Hydrodynamic pressure is treated as an independent nodal variables in the governing equations of the fluid domain, which is modeled using the standard scaling centre-based SBFEM. The coupled fluid-structure system is assembled by applying equilibrium and compatibility boundary conditions to ensure the balance of interaction forces. A synchronous solution algorithm, combined with the implicit-implicit scheme of the Newmark method, is used to determine the dynamic responses of the coupled system. The main advantage of this novel approach is that it meshes and discretizes the boundaries instead of the entire structural and fluid domains, thereby reducing computational costs. Additionally, analytical solutions can be obtained along the radial direction of the interior domain, enhancing the accuracy and convergence of the results. Another advantage is the approach's ability to provide a unified modeling framework for structures of any shape. Furthermore, the asymmetry issue of the coefficient matrix can be effectively avoided by using a synchronous solution algorithm. Benchmark examinations confirm the superior computational accuracy and robustness of the proposed approach. A comprehensive parametric study is conducted, focusing on the effects of liquid filling levels, as well as geometric and material parameters, on the transient vibration and distribution behaviors of the fluid-structure coupling system.
{"title":"A novel semi-analytical approach based on scaled boundary finite element method for fluid-structure coupling analysis of liquid sloshing in 3D containers","authors":"Wenbin Ye , Lei Gan , Haibo Wang , Quansheng Zang , Lei Qin , Jun Liu","doi":"10.1016/j.jfluidstructs.2024.104205","DOIUrl":"10.1016/j.jfluidstructs.2024.104205","url":null,"abstract":"<div><div>In this paper, a novel semi-analytical approach is proposed for the three-dimensional fluid-structure coupling analysis of liquid sloshing in elastic containers subjected to harmonic and seismic loading in the horizontal direction, based on the scaled boundary finite element method (SBFEM). A modified SBFEM model, referred to as the scaling surface-based SBFEM, is developed to simulate the container wall, which is treated as a thin shell structure. Within the framework of the scaling surface-based SBFEM, the geometry of the shell structure is entirely determined by scaling one surface of the structure. This approach differs significantly from the standard SBFEM, where approximation is achieved through coordinate mapping based on a scaling center, thereby enhancing the modeling accuracy and efficiency. Hydrodynamic pressure is treated as an independent nodal variables in the governing equations of the fluid domain, which is modeled using the standard scaling centre-based SBFEM. The coupled fluid-structure system is assembled by applying equilibrium and compatibility boundary conditions to ensure the balance of interaction forces. A synchronous solution algorithm, combined with the implicit-implicit scheme of the Newmark method, is used to determine the dynamic responses of the coupled system. The main advantage of this novel approach is that it meshes and discretizes the boundaries instead of the entire structural and fluid domains, thereby reducing computational costs. Additionally, analytical solutions can be obtained along the radial direction of the interior domain, enhancing the accuracy and convergence of the results. Another advantage is the approach's ability to provide a unified modeling framework for structures of any shape. Furthermore, the asymmetry issue of the coefficient matrix can be effectively avoided by using a synchronous solution algorithm. Benchmark examinations confirm the superior computational accuracy and robustness of the proposed approach. A comprehensive parametric study is conducted, focusing on the effects of liquid filling levels, as well as geometric and material parameters, on the transient vibration and distribution behaviors of the fluid-structure coupling system.</div></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":"131 ","pages":"Article 104205"},"PeriodicalIF":3.4,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530945","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}
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