Tackling FSI Simulation for FIV Problems in Tube Bundle Systems With POD Approach

2011 ◽  
Author(s):  
Marie Pomarede ◽  
Aziz Hamdouni ◽  
Erwan Liberge ◽  
Elisabeth Longatte ◽  
Jean-Franc¸ois Sigrist
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Tube Bundle ◽  
Fluid Structure Interaction ◽  
Flowing Fluid ◽  
Fluid Structure ◽  
Reduced Order ◽  
Structure Interaction ◽  
Flow Past ◽  
Steam Boilers

Tube bundles in steam boilers of nuclear power plants and nuclear on-board stokehold are known to be exposed to high levels of vibrations under flowing fluid. This coupled fluid-structure problem is still a challenge for engineers, first because of the difficulty to fully understand it, second because of the complexity for setting it up numerically. Although numerical techniques could help the understanding of such a mechanism, a complete simulation of a fluid past a whole elastically mounted tube bundle is currently out of reach for engineering purposes. To get round this problem, the use of a reduced-order model has been proposed with the introduction of the widely used Proper Orthogonal Decomposition (POD) method for a flow past a fixed structure [M. Pomare`de, E. Liberge, A. Hamdouni, E.Longatte, & J.F. Sigrist - Simulation of a fluid flow using a reduced-order modelling by POD approach applied to academic cases; PVP2010, July 18–22, Seattle]. Interesting results have been obtained for the reconstruction of the flow. Here a first step is to propose to consider the case of a flow past a fixed tube bundle configuration in order to check the good reconstruction of the flow. Then, an original approach proposed by Liberge (E. Liberge; POD-Galerking Reduction Models for Fluid-Structure Interaction Problems, PhD Thesis, Universite´ de La Rochelle, 2008) is applied to take into account the fluid-structure interaction characteristic; the so-called “multiphase” approach. This technique allows applying the POD method to a configuration of a flow past an elastically mounted structure. First results on a single circular cylinder and on a tube bundle configuration are encouraging and let us hope that parametric studies or prediction calculations could be set up with such an approach in a future work.

Simulation of Fluid Flow Using Reduced-Order Modeling by POD Approach Applied to a Fixed Tube Bundle System

2010 ◽  
Author(s):  
Marie Pomarede ◽  
Erwan Liberge ◽  
Aziz Hamdouni ◽  
Elisabeth Longatte ◽  
Jean-Franc¸ois Sigrist
Keyword(s):  
Dynamic Analysis ◽  
Steam Generator ◽  
Tube Bundle ◽  
Fluid Structure Interaction ◽  
Reduced Model ◽  
Steam Generator Tube ◽  
Fluid Structure ◽  
Reduced Order ◽  
Structure Interaction ◽  
Tube Bundles

Tube bundles in steam boilers of nuclear power plants and nuclear on-board stokehold are known to be exposed to high levels of vibrations. This coupled fluid-structure problem is very complex to numerically set up, because of its three-dimensional characteristics and because of the large number of degrees of freedom involved. A complete numerical resolution of such a problem is currently not viable, all the more so as a precise understanding of this system behaviour needs a large amount of data, obtained by very expensive calculations. We propose here to apply the now classical reduced order method called Proper Orthogonal Decomposition to a case of 2D flow around a tube bundle. Such a case is simpler than a complete steam generator tube bundle; however, it allows observing the POD projection behaviour in order to project its application on a more realistic case. The choice of POD leads to reduced calculation times and could eventually allow parametrical investigations thanks to a low data quantity. But, it implies several challenges inherent to the fluid-structure characteristic of the problem. Previous works on the dynamic analysis of steam generator tube bundles already provided interesting results in the case of quiescent fluid [J.F. Sigrist, D. Broc; Dynamic Analysis of a Steam Generator Tube Bundle with Fluid-Structure Interaction; Pressure Vessel and Piping, July 27–31, 2008, Chicago]. Within the framework of the present study, the implementation of POD in academic cases (one-dimensional equations, 2D-single tube configuration) is presented. Then, firsts POD modes for a 2D tube bundle configuration is considered; the corresponding reduced model obtained thanks to a Galerkin projection on POD modes is finally presented. The fixed case is first studied; future work will concern the fluid-structure interaction problem. Present study recalls the efficiency of the reduced model to reproduce similar problems from a unique data set for various configurations as well as the efficiency of the reduction for simple cases. Results on the velocity flow-field obtained thanks to the reduced-order model computation are encouraging for future works of fluid-structure interaction and 3D cases.

An Overview of Numerical Method for Fluid-Structure Interaction

2014 ◽  
Author(s):  
J.-H. Jeong ◽  
M. Kim ◽  
P. Hughes
Keyword(s):  
Numerical Simulation ◽  
Numerical Methods ◽  
Nuclear Power ◽  
Power Plants ◽  
Fluid Structure Interaction ◽  
Phase Flow ◽  
Two Phase ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Deformable Structure

Fluid-structure interaction (FSI) is the interaction of some movable or deformable structure with an internal or surrounding fluid flow. Therefore, fluid-structure interaction problems are too complex to solve analytically and so they have to be analysed by means of experiments or numerical simulation. This paper provides an overview of numerical methods for fluid-structure interaction evaluation in an draft IAEA technical guideline: large eddy simulation (LES), direct numerical simulation (DNS), Lattice-Boltzmann method (LBM), finite element method (FEM) and computational fluid dynamics (CFD) method. In addition to providing general applications of numerical methods for fluid-structure interaction evaluation, the paper also describes some cases applied for problems associated with single-phase flow and two-phase flow in nuclear power plants.

Study of a Fluid-Structure Interaction Instability Mechanism in a Tube Bundle With Multiphase-POD Approach

2013 ◽  
Author(s):  
Marie Pomarède ◽  
Erwan Liberge ◽  
Jean-François Sigrist ◽  
Aziz Hamdouni ◽  
Elisabeth Longatte
Keyword(s):  
Tube Bundle ◽  
Low Cost ◽  
Fluid Structure Interaction ◽  
Computational Cost ◽  
Order Method ◽  
Instability Mechanism ◽  
Cost Study ◽  
Fluid Structure ◽  
Reduced Order ◽  
Structure Interaction

Multiphase-Proper Orthogonal Decomposition Reduced-Order Method has been proven to be efficient for the low-cost study of fluid-structure interaction mechanisms. Applications to a single tube under cross-flow, then to a tube bundle system revealed good behaviours of this method, which was shown to be able to accurately reproduce the velocity flow field as well as the solid displacement, even in the case of large magnitudes. The goal here is to go further by studying an instability mechanism with the Multiphase-POD technique, involving a tube array configuration because of its high interest in the nuclear domain. We first want to know if this method can reproduce critical to unstable cases and finally, we are interested in the possibility of leading a parametric study coupled with the Multiphase-POD Method in order to evaluate the instability threshold. Indeed, parametric studies coupled with a reduced-order method could lead to a CPU time additional gain, since only one basis calculation could cover several configurations with low computational cost.

Simulation of Fluid Flow Using Reduced-Order Modeling by POD Approach Applied to Academic Cases

2010 ◽  
Author(s):  
Marie Pomarede ◽  
Aziz Hamdouni ◽  
Erwan Liberge ◽  
Elisabeth Longatte ◽  
Jean-Franc¸ois Sigrist
Keyword(s):  
Dynamic Analysis ◽  
Steam Generator ◽  
Power Plants ◽  
Tube Bundle ◽  
Data Set ◽  
Steam Generator Tube ◽  
Flowing Fluid ◽  
Fluid Structure ◽  
Reduced Order ◽  
Tube Bundles

Tube bundles in steam boilers of nuclear power plants and nuclear on-board stokehold are known to be exposed to high levels of vibrations. This coupled fluid-structure problem is very complex to numerically set up, because of its three-dimensional characteristics and because of the large number of degrees of freedom involved. A complete numerical resolution of such a problem is currently not viable, all the more so as a precise understanding of this system behaviour needs a large amount of data, obtained by very expensive calculations. We propose here to apply the now classical reduced order method called Proper Orthogonal Decomposition to this case. This choice could lead to reduced calculation times and allow parametrical investigations thanks to a low data quantity. But, it implies several challenges inherent to the fluid-structure characteristic of the problem. Previous works on the dynamic analysis of steam generator tube bundles already provided interesting results in the case of non flowing fluid — i.e. quiescent fluid [J.F. Sigrist, D. Broc; Dynamic Analysis of a Steam Generator Tube Bundle with Fluid-Structure Interaction; Pressure Vessel and Piping, July 27–31, 2008, Chicago]. A first step on the implementation of POD in academic cases (one-dimensional equations, 2D-single tube configuration) is presented. Future work will consist in working on the tube bundle configuration, first in the fixed case and then with structure motion allowed. Present study shows the efficiency of the reduced model to reproduce similar problems from a unique data set for various configurations as well as the efficiency of the reduction for simple cases.

Pipe Rupture Analysis Considering Fluid-Structure Interaction

2011 ◽  
Author(s):  
Yukari Hamamoto ◽  
Makoto Toyoda
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Thrust Force ◽  
Fluid Structure Interaction ◽  
Low Carbon ◽  
Analysis Model ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Analysis ◽  
Autogenous Control

Global warming is caused by the emission of greenhouse gases, like CO2. Nuclear energy is one of the main sources of low-carbon energy. In the events of serious accidents, a nuclear power plant may emit radioactivity that is harmful to human health. Nuclear power should be used after enough evidence of its safety is provided. Measures for safety of nuclear power plants, such as autogenous control and LBB, have been developed. Moreover, there is requirement with respect to the design, safety, equipments components and systems of nuclear plant. For example, it is necessary to place components that restrain pipe whip behavior, and to design peripheral equipments that may be affected by high-pressured fluid in pipe rupture accidents [1], [2]. In the case of pipe rupture that occurs to structures such as nuclear plants and steam generators, a pipe deforms releasing its inner high-pressured fluid. In previous studies, the pipe whip behavior analyses have been performed by using blowdown thrust force that is estimated by fluid analysis. In this study, we simulate pipe whip behavior and reduction of blowdown thrust force by releasing inner fluid to the atmosphere. The analysis model is an elbow pipe and high-pressure fluid running inside. We considered fluid-structure interaction effect in the analysis because ovalization of the cross-section of the elbow part as well as a change of the elbow torus radius affects fluid flow blowing out from the ruptured part of the pipe.

Analysis on Fluid-Structure Interaction Dynamic Characteristics of Steam Generator Heat Exchanger Tubes

2011 ◽  
Vol 382 ◽  
pp. 52-55
Author(s):  
Li Na Zhang ◽  
Su Zhen Wang
Keyword(s):  
Steam Generator ◽  
Dynamic Characteristics ◽  
Nuclear Power ◽  
Power Plants ◽  
Fluid Structure Interaction ◽  
Finite Element Program ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Dynamic ◽  
Steam Generator Tubes

The fluid-structure interaction (FSI) dynamic characteristics of steam generator tubes counting for much with safety of an operating nuclear power plants are investigated by analytical methods based on dynamics mechanics and FSI theories. By using the parametric design language APDL of finite element program ANSYS, intelligently dividing model, setting up material and geometric parameters, the models of tubes with internal and external fluid, the different factors influencing on fluid-structure interaction dynamic characteristics of steam generator tubes are investigated by numerical method.

Extending a Van der Pol Based Reduced-Order Model for Fluid-Structure Interaction Applied to Non-Synchronous Vibrations in Turbomachinery

2021 ◽  
Author(s):  
Richard Hollenbach ◽  
Robert Kielb ◽  
Kenneth Hall
Keyword(s):  
Fluid Structure Interaction ◽  
Reduced Order Model ◽  
Van Der Pol Oscillator ◽  
Previous Model ◽  
Stable Limit ◽  
Order Model ◽  
Van Der Pol ◽  
Fluid Structure ◽  
Reduced Order ◽  
Structure Interaction

Abstract This paper expands upon a multi-degree-of-freedom, Van der Pol oscillator used to model buffet and Nonsynchronous Vibrations (NSV) in turbines. Two degrees-of-freedom are used, a fluid tracking variable incorporating a Van der Pol oscillator and a classic spring, mass, damper mounted cylinder variable; thus, this model is one of fluid-structure interaction. This model has been previously shown to exhibit the two main aspects of NSV. The first is the lock-in or entrainment phenomenon of the fluid shedding frequency jumping onto the natural frequency of the oscillator, while the second is a stable limit cycle oscillation (LCO) once the transient solution disappears. Improvements are made to the previous model to better understand this aeroelastic phenomenon. First, an error minimizing technique through a system identification method is used to tune the coefficients in the Reduced Order Model (ROM) to improve the accuracy in comparison to experimental data. Secondly, a cubic stiffness term is added to the fluid equation; this term is often seen in the Duffing Oscillator equation, which allows this ROM to capture the experimental behavior more accurately, seen in previous literature. The finalized model captures the experimental cylinder data found in literature much better than the previous model. These improvements also open the door for future models, such as that of a pitching airfoil or a turbomachinery blade, to create a preliminary design tool for studying NSV in turbomachinery.

Reduced-Order Modeling and Experimental Studies of Two-Way Coupled Fluid-Structure Interaction in Flapping Wings

2019 ◽  
Author(s):  
Ryan K. Schwab ◽  
Heidi E. Reid ◽  
Mark A. Jankauski
Keyword(s):  
Fluid Structure Interaction ◽  
Experimental Studies ◽  
Flapping Wing ◽  
Flexible Wings ◽  
Single Degree Of Freedom ◽  
Fluid Structure ◽  
Reduced Order ◽  
Structure Interaction ◽  
Rotation Stage ◽  
Computational Resources

Abstract Flapping, flexible wings deform under both aerodynamic and inertial loads. However, the fluid-structure interaction (FSI) governing flapping wing dynamics is not well understood. Conventional FSI models require excessive computational resources and are not conducive to parameter studies that consider variable wing kinematics or geometry. Here, we present a simple two-way coupled FSI model for a wing subjected to single-degree-of-freedom (SDOF) rotation. The model is reduced-order and can be solved several orders of magnitude faster than direct computational methods. We construct a SDOF rotation stage and measure basal strain of a flapping wing in-air and in-vacuum to study our model experimentally. Overall, agreement between theory and experiment is excellent. In-vacuum, the wing has a large 3ω response when flapping at approximately 1/3 its natural frequency. This response is attenuated substantially when flapping in-air as a result of aerodynamic damping. These results highlight the importance of two-way coupling between the fluid and structure, since one-way coupled approaches cannot describe such phenomena. Moving forward, our model enables advanced studies of biological flight and facilitates bio-inspired design of flapping wing technologies.

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