Subspace Iteration for Eigen-Solution of Fluid-Structure Interaction Problems

1987 ◽  
Vol 109 (2) ◽  
pp. 244-248 ◽  
Author(s):  
I.-W. Yu
Keyword(s):  
Structural Dynamics ◽  
Iteration Method ◽  
Eigenvalue Problems ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Real Form ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Subspace Iteration ◽  
Symmetric Eigenvalue Problems

The subspace iteration method, commonly used for solving symmetric eigenvalue problems in structural dynamics, can be extended to solve nonsymmetric fluid-structure interaction problems in terms of fluid pressure and structural displacement. The two cornerstones for such extension are a nonsymmetric equation solver for the inverse iteration and a nonsymmetric eigen-procedure for subspace eigen-solution. The implementation of a nonsymmetric equation solver can easily be obtained by modifying the existing symmetric procedure; however, the nonsymmetric eigen-solver requires a new procedure such as the real form of the LZ-algorithm. With these extensions the subspace iteration method can solve large fluid-structure interaction problems by extracting a group of eigenpairs at a time. The method can generally be applied to compressible and incompressible fluid-structure interaction problems.

scholarly journals Fluid–structure interaction analysis of fluid pressure pulsation and structural vibration features in a vertical axial pump

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982858
Author(s):  
Liaojun Zhang ◽  
Shuo Wang ◽  
Guojiang Yin ◽  
Chaonian Guan
Keyword(s):  
Pressure Pulsation ◽  
Interaction Analysis ◽  
Equivalent Stress ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Structural Vibration ◽  
Interaction Method ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Axial Pump

Current studies on the operation of the axial pump mainly focus on hydraulic performances, while the coupled interaction between the fluid and structure attracts little attention. This study aims to provide numerical investigation into the vibration features in a vertical axial pump based on two-way iterative fluid–structure interaction method. Three-dimensional coupling model was established with high-quality structured grids of ADINA software. Turbulent flow features were studied under design condition, using shear–stress transport k-ω turbulence model and sliding mesh approach. Typical measure points along and perpendicular to flow direction in fluid domain were selected to analyze pressure pulsation features of the impeller and fixed guide vane. By contrast, vibration features of equivalent stress in corresponding structural positions were investigated and compared based on fluid–structure interaction method. In order to explore fluid–structure interaction vibration mechanism, distribution of main frequencies and amplitudes of the measure points was presented based on the Fast Fourier Transformation method. The results reveal the time and frequency law of fluid pressure pulsation and structural vibration at the same position in the vertical axial pump while additionally provide important theoretical guidance for optimization design and safe operation of the vertical axial pump.

Sequential Fluid-Structure Interaction of a Large-Scale Gas Control Valve

2010 ◽  
Vol 455 ◽  
pp. 146-150
Author(s):  
Fang Cao ◽  
Yong Wang ◽  
Y.T. An
Keyword(s):  
Large Scale ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Control Valve ◽  
Practical Significance ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Gas Control ◽  
Stress And Deformation ◽  
Pressure Stress

According to the real structure and work condition of a large-scale gas control valve used in recycling generating electricity project, a sequential fluid-structure interaction system model of control valve is set up, the coupling of fluid and valve plug is studied. The complicated fluid pressure, stress and deformation of balanced valve plug and stem at different control valve openings are investigated. The root cause of plug vibration by fluid is revealed. The natural frequency and modes of vibration are obtained, which could verify whether the design overcomes resonance. All of these are in favor of realizing design optimization in fluid-structure interaction and are of great practical significance for advancing study on large-scale control valves.

Coupling of Lattice Boltzmann and Finite Element Methods for Fluid-Structure Interaction Application

2006 ◽  
Author(s):  
Y. W. Kwon
Keyword(s):  
Finite Element ◽  
Structural Dynamics ◽  
Lattice Boltzmann ◽  
Fluid Structure Interaction ◽  
The Finite Element Method ◽  
Interface Boundary ◽  
Structural Domains ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Boltzmann Method

In order to analyze the Fluid-Structure Interaction (FSI) between a flow and a flexible structure, an algorithm was presented to couple the Lattice Boltzmann Method (LBM) and the Finite Element Method (FEM). The LBM was applied to the fluid dynamics while the FEM was applied to the structural dynamics. The two solution techniques were solved in a staggered manner, i.e. one solver after another. Continuity of the velocity and traction was applied at the interface boundaries between the fluid and structural domains. Furthermore, so as to make the fluid-structure interface boundary more flexible in terms of the computational modeling perspective, a technique was also developed for the LBM so that the interface boundary might not coincide with the fluid lattice mesh. Some example problems were presented to demonstrate the developed techniques.

Fluid Structure Interaction Analysis of Stentless Bio-Prosthetic Aortic Heart Valve in Sinus of Valsalva

2010 ◽  
Author(s):  
Esfandyar Kouhi ◽  
Yos Morsi
Keyword(s):  
Blood Flow ◽  
Heart Valve ◽  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Von Mises Stress ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aortic Heart Valve ◽  
Von Mises

In this paper the fluid structure interaction in stentless aortic heart valve during acceleration phase was performed successfully using the commercial ANSYS/CFX package. The aim is to provide unidirectional coupling FSI analysis of physiological blood flow within an anatomically corrected numerical model of stentless aortic valve. Pulsatile, Newtonian, and turbulent blood flow rheology at aortic level was applied to fluid domain. The proposed structural prosthesis had a novel multi thickness leaflet design decreased from aortic root down to free age surface. An appropriate interpolation scheme used to import the fluid pressure on the structure at their interface. The prosthesis deformations over the acceleration time showed bending dominant characteristic at early stages of the cardiac cycle. More stretching and flattening observed in the rest of the times steps. The multi axial Von Mises stress data analysis was validated with experimental data which confirmed the initial design of the prosthesis.

scholarly journals A Fluid-Structure Interaction Model for Dam-Water Systems: Analytical Study and Application to Seismic Behavior

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Ricardo Faria ◽  
Sérgio Oliveira ◽  
Ana L. Silvestre
Keyword(s):  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Interaction Model ◽  
Arch Dam ◽  
Energy Estimates ◽  
Space Representation ◽  
Discrete Problem ◽  
Order Problem ◽  
Fluid Structure ◽  
Structure Interaction

We consider a dam-water system modeled as a fluid-structure interaction, specifically, a coupled hyperbolic second-order problem, formulated in terms of the displacement of the structure and the fluid pressure. Firstly, we investigate the well posedness of the corresponding variational formulation using Galerkin approximations, energy estimates, and mollification. Then, we apply the finite element method along with the state-space representation of the discrete problem in order to perform a 3D numerical simulation of Cabril arch dam (Zêzere river, Portugal). The numerical model is validated by comparison with available experimental data from a monitoring vibration system installed in Cabril dam.

Numerical investigation of flexible flapping wings using computational fluid dynamics/computational structural dynamics method

2016 ◽  
Vol 232 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Long Liu ◽  
Hongda Li ◽  
Haisong Ang ◽  
Tianhang Xiao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Structural Dynamics ◽  
Fluid Structure Interaction ◽  
Flapping Wings ◽  
Structural Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Non Linear ◽  
Computational Structural Dynamics

A fluid–structure interaction numerical simulation was performed to investigate the flow field around a flexible flapping wing using an in-house developed computational fluid dynamics/computational structural dynamics solver. The three-dimensional (3D) fluid–structure interaction of the flapping locomotion was predicted by loosely coupling preconditioned Navier–Stokes solutions and non-linear co-rotational structural solutions. The computational structural dynamic solver was specifically developed for highly flexible flapping wings by considering large geometric non-linear characteristics. The high fidelity of the developed methodology was validated by benchmark tests. Then, an analysis of flexible flapping wings was carried out with a specific focus on the unsteady aerodynamic mechanisms and effects of flexion on flexible flapping wings. Results demonstrate that the flexion will introduce different flow fields, and thus vary thrust generation and pressure distribution significantly. In the meanwhile, relationship between flapping frequency and flexion plays an important role on efficiency. Therefore, appropriate combination of frequency and flexion of flexible flapping wings provides higher efficiency. This study may give instruction for further design of flexible flapping wings.

Interpolation Methods Used for One-Way Fluid Structure Interaction of Hydrodynamic Coupling

2014 ◽  
Vol 513-517 ◽  
pp. 4298-4301
Author(s):  
Xiu Quan Lu ◽  
Wei Cai ◽  
Wen Xing Ma ◽  
Yue Shi Wu ◽  
Wen Xu
Keyword(s):  
Manufacturing Process ◽  
Interaction Analysis ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Hydrodynamic Coupling ◽  
Design And Manufacturing

In the design and manufacturing process of the hydrodynamic coupling, the fluid pressure on the impeller is difficult to calculate when analyzing the strength of the impeller. We can use the one-way fluid-structure interaction analysis. When interpolate the pressure on the flow field and structural coordinate values, choosing reasonable interpolation method can reduce the amount of computation, improve accuracy, simplify product design and manufacturing process. This article is based on one-way fluid-structure interaction analysis. We compare the four interpolation method in MATLAB, conclude that the spline interpolation is better than others. It is the most suitable for practical applications, which can simplify the design of the manufacturing process of the hydrodynamic coupling.

A Fluid-Structure Interaction Modeling Approach of Lubricated Bearing-Type Sliding Contacts

2012 ◽  
Author(s):  
Jeremiah N. Mpagazehe ◽  
C. Fred Higgs
Keyword(s):  
Reynolds Equation ◽  
Moving Boundary ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Navier Stokes ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Processing Power ◽  
Interaction Modeling

In many tribological applications, such as journal bearings and gears, a fluid film is used to accommodate velocity between moving surfaces. To model the behavior of this film and to predict its ability to carry load, the Reynolds equation is predominantly employed. As computational processing power continues to increase, computational fluid dynamics (CFD) is increasingly being employed to predict the fluid behavior in lubrication environments. Using CFD is advantageous in that it can provide a more general approximation to the Navier-Stokes equations than the Reynolds equation. Moreover, using CFD allows for the simulation of multiphase flows as could occur during bearing contamination and bearing exit conditions. Because the bearing surfaces move relative to each other as they obtain equilibrium with the fluid pressure, there is a need to incorporate the moving boundary into the CFD calculation, which is a non-trivial task. In this work, a fluid-structure interaction (FSI) technique is explored as an approach to model the dynamic coupling between the moving bearing surfaces and the lubricant. The benefits of using an FSI approach are discussed and the results of its implementation in a lubricated sliding contact model are presented.

An Immersed Boundary Proper Generalized Decomposition (IB-PGD) for Fluid–Structure Interaction Problems

2018 ◽  
Vol 15 (06) ◽  
pp. 1850045
Author(s):  
C. Le-Quoc ◽  
Linh A. Le ◽  
V. Ho-Huu ◽  
P. D. Huynh ◽  
T. Nguyen-Thoi
Keyword(s):  
Fluid Flow ◽  
Stokes Equations ◽  
Complex Geometry ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Immersed Boundary ◽  
Proper Generalized Decomposition ◽  
Time Step ◽  
Fluid Structure ◽  
Structure Interaction

Proper generalized decomposition (PGD), a method looking for solutions in separated forms, was proposed recently for solving highly multidimensional problems. In the PGD, the unknown fields are constructed using separated representations, so that the computational complexity scales linearly with the dimension of the model space instead of exponential scaling as in standard grid-based methods. The PGD was proven to be effective, reliable and robust for some simple benchmark fluid–structure interaction (FSI) problems. However, it is very hard or even impossible for the PGD to find the solution of problems having complex boundary shapes (i.e., problems of fluid flow with arbitrary complex geometry obstacles). The paper hence further extends the PGD to solve FSI problems with arbitrary boundaries by combining the PGD with the immersed boundary method (IBM) to give a so-called immersed boundary proper generalized decomposition (IB-PGD). In the IB-PGD, a forcing term constructed by the IBM is introduced to Navier–Stokes equations to handle the influence of the boundaries and the fluid flow. The IB-PGD is then applied to solve Poisson’s equation to find the fluid pressure distribution for each time step. The numerical results for three problems are presented and compared to those of previous publications to illustrate the robustness and effectiveness of the IB-PGD in solving complex FSI problems.

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