检索结果-内蒙古大学图书馆

fluid-elastic structure interaction simulation by using ordinary state-based peridynamics and peridynamic differential operator

引用

ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS 2020年 121卷 126-142页

作者： Gao, Yan Oterkus, Selda Univ Strathclyde Dept Naval Architecture Ocean & Marine Engn 100 Montrose St Glasgow G4 0LZ Lanark Scotland

The fluid-structure interaction phenomenon is often encountered in the ocean engineering field. In the present work, a non-local numerical model is developed for the simulations of weakly compressible viscous fluid and elastic structure interactions. The peridynamic theory is adopted for both the structure and fluid modelling. The elastic structure is described by using the ordinary state-based peridynamics, while the fluid is modelled by utilizing the peridynamic differential operator. Furthermore, the updated Lagrangian description is adopted for the fluid including the relative deformation gradient expressed by the peridynamic differential operator. The fluid-structure interface and its normal direction are calculated via the gradient of a colour function, which varies with the fluid motion and structure deformation. Besides, the interaction force exerted from fluid to structure is constrained to be always perpendicular to the moving interface. Hence the fluid motion and structural deformation are predicted simultaneously. The validation of the developed model is conducted through the simulation of a water dam break with a rubber gate. The good agreement between the peridynamic and the experiment results demonstrates the capability of the current model for solving fluid-elastic structure interaction problems.

关键词： Ordinary state-based peridynamics Peridynamic differential operator Non-local fluid-structure interaction Dam break

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction Simulations in Applications for Nuclear Engineering

Fluid-Structure Interaction Simulations in Applications for ...

引用

作者： Brockmeyer, Landon Mitchell Texas A&M University

学位级别：Ph.D., Doctor of Philosophy

Nuclear reactors pump coolant through their core and heat exchangers at massive mass flow rates to sustain energy production. These demanding requirements push engineers to extreme levels of optimization to safely sustain the transfer of energy. High flow rates introduce the possibility of flow-induced vibrations. Reactor core and heat-exchanger/steam generator designs go through many stages of experimentation to ensure that problematic flow-induced vibrations do not arise. Advances in computational capabilities introduce the possibility of creating predictive simulations that accelerate the iterative design process and replace expensive physical experiments. Simulation methods for fluid-structure interactions are rapidly developing and undergoing extensive verification and validation. Computational fluid dynamics code Nek5000 and computational structural mechanics code Diablo have been coupled to create a highly scalable, high-fidelity fluid-structure interaction code. A fully coupled model of crossflow through a tube bundle has been simulated using the Nek5000-Diablo code for validation purposes. Simulations at three velocities were performed to test the method’s capabilities of capturing the onset of large amplitude vibrations that occur at a critical velocity for the tube bundle. The simulation results compared favorably to the experiment on which it was based and gave further insight into the mechanisms behindthe vibrations. A 7-pin bundle of wire-wrapped fuel pins was simulated using Nek5000 and the forces exerted on the pins captured. A scheme was developed to synthesize force histories of indefinite length replicating the Nek5000 force signals, forming a modifiedone-directional coupling procedure. Multiple structure simulations were performed, observing the effects of pin-to-pin, and pin-to shroud contact scenarios on the resulting vibrations. The shroud was found to effectively limit vibrations to short wave-lengths onthe order of 1/6th helical pitch even w

关键词： Flow-induced vibrations fluid-structure interaction Crossflow Wire-wrap Energy transfer

来源：评论

学校读者我要写书评

暂无评论

Effects of fluid-structure interaction on Nonlinear Seismic Response of Deep-water Hollow Bridge Pier

Effects of Fluid-structure Interaction on Nonlinear Seismic ...

引用

第五届智能交通、大数据及智慧城市国际会议

作者： Zheng Wei Yulin Deng Xiong Ge Department of Road and Bridge Engineering School of transportationWuhan University of Technology

This paper uses numerical method to investigate the characteristics of nonlinear seismic responses of a typical deep-water hollow bridge *** the bilinear moment-curvature beam elements and 3 D solid elements modeling the hollow pier and potential-based fluid elements modeling the water domain,three dimensional finite element models for the typical deep-water bridge pier are built,and the numerical model is verified to be *** nonlinear time history analyses,seismic responses of the deep-water bridge pier under different water levels are studied for two cases where the hollow piers contact with outer water only and both outer and inner *** numerical results indicates that seismic responses of the deep water hollow pier increase generally with water level,especially the shear force response of the pier bottom which is obviously enlarged by fluid-structure interaction since a low water *** bridge piers submerged in deep water,the bending moment of the pier bottom is greater than that of dry bridge piers,which makes it easier for the pier bottom to *** the yielding happens,the curvature ductility demand of the bottom section is significantly amplified,and the damage index of the bridge pier is distinctly *** existence of the inner water would cause further demand of the curvature ductility which may lead to aggravated damages to the deep-water *** findings can provide valuable guidance for future deep-water bridge design.

关键词： Deep-water Hollow Bridge Pier Outer Water Inner Water fluid-structure interaction Nonlinear Time History Analysis Nonlinear Seismic Response Curvature Demand Damage

来源：评论

学校读者我要写书评

暂无评论

A Variational Implementation of Immersed Boundary Method for fluid-structure interaction problems

A Variational Implementation of Immersed Boundary Method for...

引用

作者： Abhishek Mishra University at Buffalo The State University of New York

学位级别：硕士

The Immersed Boundary Method (IBM) was designed by Peskin for modeling fluid-structure interaction (FSI) problems, where a structure is completely immersed in a fluid, in contrast to the arbitrary Lagrangian-Eulerian (ALE) method, which consists of a conforming inter- face between the fluid and the solid. In the original IBM, the Navier-Stokes equations are considered everywhere and the presence of the immersed solid is taken into account using a Dirac delta distribution term which depends on the position of the solid. Recently, a finite element version of the IBM was developed by Boffi et. al., which avoids explicit treatment of the Dirac delta distribution term. In this approach, equations governing the fluid and solid motion are discretized using finite element method (FEM). The Navier-Stokes equations are solved first using the solid position at previous time step, and then the solid position is updated according to the computed velocity. A modification to this approach was also proposed by Boffi et. al., a fictitious domain formulation of the finite element IBM, that makes use of a distributed Lagrange multiplier, enforcing a constraint on the velocity matching of the solid and the fluid. In this work, we propose a new formulation based on the nonlinear solid mechan- ics formulations, which properly enforces incompressibility constraints, that corrects any volumetric instabilities that may occur due to discretization of incompressible hyperelastic materials. We numerically investigate some FSI problems using our proposed formulation. The computational algorithm for the implementation of our IBM formulation has been developed using GRINS, a C++ software framework, based on the libMesh finite element library, designed to simulate multiphysics systems of partial differential equations (PDEs) using FEM.

关键词： immersed boundary method finite element method fluid-structure interaction fictitious domain variational distributed Lagrange multiplier volumetric stabilization

来源：评论

学校读者我要写书评

暂无评论

Initial Stage of fluid-structure interaction of a Celestial Icosahedron Shaped Vacuum Lighter Than Air Vehicle

Initial Stage of Fluid-Structure Interaction of a Celestial ...

引用

作者： Dustin P. Graves AIR UNIVERSITY

学位级别：硕士

The analysis of a celestial icosahedron geometry is considered as a potential design for a Vacuum Lighter than Air Vehicle (VLTAV). The goal of the analysis is ultimately to understand the initial fluid-structure interaction of the VLTAV and the surrounding airflow. Up to this point, previous research analyzed the celestial icosahedron VLTAV in relation to withstanding a symmetric sea-level pressure applied to the membrane of the structure. This scenario simulates an internal vacuum being applied in the worst-case atmospheric environmental condition. The next step in analysis is to determine the aerodynamic effects of the geometry. The experimental setup for obtaining aerodynamic effects is validated prior to analyzing the deformed celestial icosahedron geometry by analyzing a perfect sphere utilizing the same manufacturing process and setup expected to be adopted for the celestial icosahedron experiments. The data received from Computational fluid Dynamics (CFD) analysis of the deformed structure in collaboration with Wright State University is used to determine the significance of aerodynamic effects on the structure. The pressure profiles experienced in the wind tunnel experiments and CFD analysis are comparatively similar. Therefore, the CFD data is used to conduct a structural analysis in which aerodynamic effects are incorporated. The research concluded that the aerodynamic pressures do not significantly affect the stress on the structure. As a result, it recommended that a full nonlinear fluid- structure interaction analysis is not necessary for this structure.

关键词： fluid-structure interaction Lighter than Air Vehicle Structural Analysis Computational fluid Dynamics

来源：评论

学校读者我要写书评

暂无评论

Numerical methodology for fluid-structure interaction analysis of nuclear fuel plates under axial flow conditions

引用

NUCLEAR ENGINEERING AND DESIGN 2018年 333卷 76-86页

作者： Mantecon, Javier Gonzalez Mattar Neto, Miguel IPEN CNEN SP Inst Pesquisas Energet Nucl Ave Prof Lineu Prestes 2242Cidade Univ BR-05508000 Sao Paulo SP Brazil

Shell-type fuel elements are widely used in nuclear research reactors. The nuclear fuel is contained in parallel shells, flat or curved, that are separated by narrow channels through which the fluid flows to remove the heat generated by fission reactions. A major problem of this fuel assembly design is the hydraulic instability of the shells caused by the high flow velocities. The objective of the study presented here is the development of a fluid-structure interaction methodology to investigate numerically the onset of hydroelastic instability of flat-shelltype fuel elements, also known as plate-type fuel assemblies, under axial flow conditions. The system analyzed consists of two nuclear fuel plates bounded by three-equal coolant channels. It is developed using the commercial codes ANSYS CFX for modeling the fluid flow and ANSYS Mechanical to model the plates. The fluid-structure interaction methodology predicts a behavior consistent with other theoretical and experimental works. Particularly, the maximum deflection of the plates is detected at the leading edge and it is a linear function of the square of the fluid velocity up to the Miller's theoretical value. For velocities above this value, a nonlinear relationship is observed. This relationship indicates that structural changes are taking place in the plates. Furthermore, for fluid velocities greater than the Miller's velocity, an extra deflection peak is observed near the trailing edge of the plates. Thus, structural alterations also happen along the length of the flat-shells.

关键词： Plate-type fuel element fluid-structure interaction Critical velocity Research reactor Hydroelastic instability

来源：评论

学校读者我要写书评

暂无评论

One-fluid formulation for fluid-structure interaction with free surface

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2018年第Apr.15期332卷 102-135页

作者： Yang, Liang Imperial Coll London Dept Earth Sci & Engn South Kensington Campus London SW7 2AZ England

A simple and efficient computational framework is presented for the simulation of fluid-structure interaction problems involving rigid body and multiphase flows in the context of hydrodynamics. Unlike existing publications, this method does not solve the general motion of rigid bodies in the Lagrangian form of Newton's law. Derived from the distributed Lagrange multiplier treatment of the rigid body, a new set of governing equations is presented on the fully Eulerian one-fluid formulation. To solve the problem numerically, the complex problem is separated into three parts: balance of the momentum and mass (dynamic problem), evolving of the Heaviside function by the external velocity (geometric problem) and rigid motion projection (kinematic problem). The conservation of mass and momentum is guaranteed by the multiphase fluid solver. The water, air and structure coupling is accomplished by the smeared interface. A new way of initialisation and convection of the rigid Heaviside function is designed for an arbitrary shape. To deal with rigid velocity vector, a linear least square method is proposed. The excellent agreement between the numerical experiment and the reference data from experiments demonstrate the validity and applicability of the new methodology (C) 2017 Elsevier B.V. All rights reserved.

关键词： One-fluid formulation fluid-structure interaction Heaviside initialisation and interpolation Linear least square projection Water impact

来源：评论

学校读者我要写书评

暂无评论

Numerical modeling of water hammer with fluid-structure interaction in a pipeline with viscoelastic supports

引用

JOURNAL OF fluidS AND structureS 2018年 76卷 469-487页

作者： Henclik, Slawomir Polish Acad Sci Hydropower Dept Inst Fluid Flow Machinery Ul J Fiszera 14 PL-80231 Gdansk Poland

In the paper a numerical approach to the four equation model of water hammer (WH) with fluid-structure interaction (FSI) is presented. An algorithm for numerical solution of that model in time domain based on the method of characteristics (MOC) is proposed. Special attention is paid to modeling of the influence of viscoelastic pipe supports. The boundary condition at the support is formulated as a differential equation of junction motion which is solved numerically concurrently with the MOC compatibility equations. Numerical simulations were done with the use of an own computer program. The tests were conducted for a model of real pipeline built in the lab and fastened with specific, complex, supporting system. The numerical results were compared to the experimental records and after some modeling and calibration quite a good agreement was achieved. Basic behaviors in the pressure records were identified and existed discrepancies were discussed and explained. The other physical model tested and preliminary analyzed in the paper is a straight pipeline fixed to the floor only with viscoelastic supports. Such a design created the possibility of significant displacements of the pipeline on the supports and thus allowing for effective testing of the influence of supports stiffness and damping properties on the WH behaviors. The specific initial conditions for that case were formulated, solved and implemented in a computer code. It was found that proper selection of support parameters may produce significant reduction of WH pressure amplitudes, mainly due to effective energy absorption and dissipation at the supports. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Water hammer fluid-structure interaction Four equation model Pipe vibrations Viscoelastic pipe supports Numerical methods

来源：评论

学校读者我要写书评

暂无评论

Refactorization of Cauchy's Method: A Second-Order Partitioned Method for fluid-Thick structure interaction Problems

引用

JOURNAL OF MATHEMATICAL fluid MECHANICS 2021年第3期23卷 64-64页

作者： Bukac, Martina Seboldt, Anyastassia Trenchea, Catalin Univ Notre Dame Dept Appl & Computat Math & Stat Notre Dame IN 46556 USA Univ Pittsburgh Dept Math Pittsburgh PA 15260 USA

This work focuses on the derivation and the analysis of a novel, strongly-coupled partitioned method for fluid-structure interaction problems. The flow is assumed to be viscous and incompressible, and the structure is modeled using linear elastodynamics equations. We assume that the structure is thick, i.e., modeled using the same number of spatial dimensions as fluid. Our newly developed numerical method is based on Robin boundary conditions, as well as on the refactorization of the Cauchy's one-legged 'theta-like' method, written as a sequence of Backward Euler-Forward Euler steps used to discretize the problem in time. This family of methods, parametrized by theta, is B-stable for any theta is an element of[12,1] and second-order accurate for theta=12+O(tau), where tau is the time step. In the proposed algorithm, the fluid and structure sub-problems, discretized using the Backward Euler scheme, are first solved iteratively until convergence. Then, the variables are linearly extrapolated, equivalent to solving Forward Euler problems. We prove that the iterative procedure is convergent, and that the proposed method is stable provided theta is an element of[12,1]. Numerical examples, based on the finite element discretization in space, explore convergence rates using different values of parameters in the problem, and compare our method to other strongly-coupled partitioned schemes from the literature. We also compare our method to both a monolithic and a non-iterative partitioned solver on a benchmark problem with parameters within the physiological range of blood flow, obtaining an excellent agreement with the monolithic scheme.

关键词： fluid-structure interaction Partitioned scheme Second-order convergence Strongly-coupled

来源：评论

学校读者我要写书评

暂无评论

Numerical study of active control by piezoelectric materials for fluid-structure interaction problems

引用

JOURNAL OF SOUND AND VIBRATION 2018年 435卷 23-35页

作者： Kaneko, Shigeki Hong, Giwon Mitsume, Naoto Yamada, Tomonori Yoshimura, Shinobu Univ Tokyo Bunkyo Ku 7-3-1 Hongo Tokyo 1138656 Japan

fluid-structure interaction (FSI) is a phenomenon caused by mutual interference between structures and the surrounding flow. Controlling FSI is important because FSI causes undesired vibration and it often affects the safety and lifetime of structures. Piezoelectric materials have excellent electromechanical properties to suppress vibration. As such, piezoelectric sensors and actuators are often used for reducing not only mechanical vibration but also FSI induced vibration. A number of studies have examined active control of FSI using piezoelectric materials. In the study of the control of FSI, numerical simulations are effective because they are proper for parametric studies and reduce the need for experiments. Although a number of numerical studies examined the control of FSI using piezoelectric materials, in these studies, detailed fluid analyses were not performed and the fluid force was modeled as a simple function. As such, the existing method cannot treat complicated FSI problems. Therefore, we herein propose a general-purpose system that conducts detailed electrostatic, structural, and fluid analyses and considers an active control algorithm. We design a structure-fluid-electrostatic interaction analysis system considering active control by inserting electrostatic analysis into FSI analysis solved by the partitioned iterative method and integrating the active control algorithm. In the present study, we verify the proposed system in three ways. First, while varying the material properties of the fluid, we analyze the motion of a bimorph piezoelectric actuator in a non-flowing fluid and compare the results with those of a previous study that did not take the fluid into consideration. Second, we reproduce vortex-induced vibration (VIV), which is an FSI phenomenon using the proposed system. Third, we confirm that the active control algorithm is implemented correctly by solving the suppression of VIV with the velocity feedback control. Based on these verification

关键词： fluid-structure interaction structure-fluid-electrostatic interaction Active control Smart structure Piezoelectric material Finite element method

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：