scholarly journals An overview of engineering numerical methods for the dynamic analysis of a nuclear reactor with fluid-structure interaction modelling

2009 ◽  
Vol 3 (1) ◽  
pp. 31-60
Author(s):  
Jean-François Sigrist
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Nuclear Reactor ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Modelling

Overview of DCNS Methodology on Fluid-Structure Interaction Modelling in Nuclear Pressure Vessels

2009 ◽  
Author(s):  
Jean-Franc¸ois Sigrist
Keyword(s):  
Dynamic Analysis ◽  
Nuclear Reactor ◽  
Tube Bundle ◽  
Fluid Structure Interaction ◽  
Pressure Vessels ◽  
Coupled Analysis ◽  
Element Analysis ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Modelling

The design of nuclear pressure vessel requires the description of various dynamic effects, among which fluid-structure interaction. The present paper gives on overview of DCNS R&D methodology for fluid-structure interaction modelling in nuclear pressure vessels: a global R&D program has been launched by DCNS within a collaborative framework, or the application of numerical methods in FSI to the dynamic analysis of nuclear propulsion systems (nuclear reactors and steam generators). Two applications are proposed in the paper as a conclusive example of this R&D program. 1) The dynamic analysis of a nuclear reactor with FSI is made possible by the implementation of the so-called (u, p, φ) formulation within the ANSYS code [J.F. Sigrist, S. Garreau, Dynamic Analysis of Fluid-Structure Interaction Problems with Spectral Method Using Pressure-Based Finite Elements, Finite Element Analysis in Design, 43 (4), 287–300, 2007] allowing the application of modal methods in the context of coupled fluid-structure systems; importance of FSI in the dynamic behaviour of a nuclear reactor are underlined by a fully coupled analysis. 2) The dynamic analysis of a steam generator with FSI is made possible by the implementation of an homogenisation technique within the CASTEM code [J.F. Sigrist, D. Broc, Dynamic Analysis of a Tube Bundle with Fluid-Structure Interaction Modelling Using a Homogenisation Method, Computer Methods in Applied Mechanics and Engineering, 197 (9–12), 1080–1099, 2008] allowing the description of the interactions between the confined fluid and inner structures and tube bundle in a straightforward manner.

Dynamic analysis of a nuclear reactor with fluid–structure interaction

2006 ◽  
Vol 236 (23) ◽  
pp. 2431-2443 ◽  
Author(s):  
Jean-François Sigrist ◽  
Daniel Broc ◽  
Christian Lainé
Keyword(s):  
Dynamic Analysis ◽  
Nuclear Reactor ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction

Fluid-structure interaction modelling of parachute soft-landing dynamics

2005 ◽  
Vol 47 (6-7) ◽  
pp. 619-631 ◽  
Author(s):  
Keith Stein ◽  
Tayfun E. Tezduyar ◽  
Sunil Sathe ◽  
Richard Benney ◽  
Richard Charles
Keyword(s):  
Fluid Structure Interaction ◽  
Soft Landing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Modelling

A Homogenization Method for the Modal Analysis of a Nuclear Reactor With Fluid-Structure Interaction

2006 ◽  
Author(s):  
Jean-Franc¸ois Sigrist ◽  
Daniel Broc
Keyword(s):  
Modal Analysis ◽  
Nuclear Reactor ◽  
Mass Operator ◽  
Fluid Structure Interaction ◽  
Homogenization Method ◽  
Theoretical Point ◽  
Element Discretization ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Internal Structures

The present paper exposes a homogenization method developed in order to perform the modal analysis of a nuclear reactor with fluid-structure interaction effects. The homogenization approach is used in order to take into account the presence of internal structures within the pressure vessel. A homogenization method is proposed in order to perform a numerical calculation of the frequencies and modal masses for the eigenmodes of the coupled fluid-structure problem. The technique allows the use of a simplified fluid-structure model that takes into account the presence of internal structures: the theory bases are first recalled, leading to a new formulation of the fluid-structure coupled problem. The finite element discretization of the coupled formulation leads to the modification of the classical fluid-structure interaction operators. The consistency of the formulation is established from a theoretical point of view by evaluating the total mass of the coupled system with the fluid and structure mass operator, and the modified added mass operator. The method is tested and validated on a 2D case (two concentric cylinders with periodical rigid inclusions within the annular space) and applied on the industrial case. A complete modal analysis (calculation of frequencies and modal masses) is performed on a simplified geometry of a nuclear reactor with and without internal structures. Numerical results are then compared and discussed, and the influence of the internal structures on the fluid-structure coupled phenomenon is highlighted.

Developing the Actuator Disk Model to Predict the Fluid–Structure Interaction in Numerical Simulation of Multimegawatt Wind Turbine Blades

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Ali Behrouzifar ◽  
Masoud Darbandi
Keyword(s):  
Numerical Methods ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Cone Angle ◽  
Disk Model ◽  
Fluid Structure ◽  
Aerodynamic Loads ◽  
Structure Interaction ◽  
Actuator Disk ◽  
Analytical Approaches

Abstract The fluid–structure interaction (FSI) is generally addressed in multimegawatt wind turbine calculations. From the fluid flow perspective, the semi-analytical approaches, like actuator disk (AD) model, were commonly used in wind turbine rotor calculations. Indeed, the AD model can effectively reduce the computational cost of full-scale numerical methods. Additionally, it can substantially improve the results of pure analytical methods. Despite its great advantages, the AD model has not been developed to simulate the FSI problem in wind turbine simulations. This study first examines the effect of constant (rigid) cone angle on the performance of the chosen benchmark wind turbine. As a major contribution, this work subsequently extends the rigid AD model to nonrigid applications to suitably simulate the FSI. The new developed AD-FSI solver uses the finite-volume method to calculate the aerodynamic loads and the beam theory to predict the structural behaviors. A benchmark megawatt wind turbine is simulated to examine the accuracy of the newly developed AD-FSI solver. Next, the results of this solver are compared with the results of other researchers, who applied various analytical and numerical methods to obtain their results. The comparisons indicate that the new developed solver calculates the aerodynamic loads reliably and predicts the blade deflection very accurately.

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.

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