Simulation of the fluid–structure-interaction of steam generator tubes and bluff bodies

2008 ◽  
Vol 238 (8) ◽  
pp. 2048-2054 ◽  
Author(s):  
Karl Kuehlert ◽  
Stephen Webb ◽  
David Schowalter ◽  
William Holmes ◽  
Amarvir Chilka ◽  
...  
2012 ◽  
Vol 482-484 ◽  
pp. 183-187
Author(s):  
Li Na Zhang ◽  
Hui Zhao ◽  
Min Shan Liu

For heat exchanger tube of steam generator, the relation between heat exchanger tube and fluid is typical fluid-structure interaction problem. Flow induced vibration has been found so far to be responsible for fatigue damage and failure of steam generator tubes, which will result in large economic loss and radioactive pollution. So the steam generator tubes are the weakest link in the primary coolant loop. Based on the synthesis of all sorts of factors influencing the dynamic characteristics of steam generator heat transfer tubes, establishing the heat transfer tube model, research on the weakening effect of fluid hole on fluid, the natural frequencies of the heat transfer tubes are analyzed under different fluid holes and fluid hole distance by numerical simulation.


2011 ◽  
Vol 382 ◽  
pp. 52-55
Author(s):  
Li Na Zhang ◽  
Su Zhen Wang

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.


Author(s):  
Marie Pomarede ◽  
Erwan Liberge ◽  
Aziz Hamdouni ◽  
Elisabeth Longatte ◽  
Jean-Franc¸ois Sigrist

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.


Author(s):  
Jean-Franc¸ois Sigrist ◽  
Daniel Broc

The present paper deals with the dynamic analysis of a steam generator tube bundle with fluid-structure interaction modelling. As the coupled fluid-structure problem involves a huge number of degrees of freedom to account for the tube displacements and the fluid pressure evolutions, classical coupled methods can not be applied for industrial studies. In the present case, the three-dimensional fluid-structure problem is solved with an homogenisation method, which has been previously exposed and successfully validated on a two-dimensional elementary tube bundle (J.F. Sigrist, D. Broc; Investigation of Numerical Methods for Modal Analysis of Tube Bundle with Fluid-Structure Interaction; Pressure Vessel and Piping, San Antonio, 22–26 July 2007). Formulation of the homogenisation method for general three-dimensional cases is exposed in the paper. Application to a simplified (however representative of an actual industrial nuclear component) steam generator is proposed. The problem modelling, which includes tube bundle, primary and secondary fluids and pressure vessel, is performed with an engineering finite element code in which the homogenisation technique has been implemented. From the practical point of view, the analysis highlights the major fluid-structure interaction effects on the dynamic behaviour of the steam generator; from the theoretical point of view, the study demonstrates the efficiency of the homogenisation method for periodic fluid-structure problems modelling.


2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Jean-François Sigrist ◽  
Daniel Broc

Seismic analysis of steam generator is of paramount importance in the safety assessment of nuclear installations. These analyses require, in particular, the calculation of frequency, mode shape, and effective modal mass of the system eigenmodes. As fluid-structure interaction effects can significantly affect the dynamic behavior of immersed structures, the numerical modeling of the steam generator has to take into account FSI. A complete modeling of heat exchangers (including pressure vessel, tubes, and fluid) is not accessible to the engineer for industrial design studies. In the past decades, homogenization methods have been studied and developed in order to model tubes and fluid through an equivalent continuous media, thus avoiding the tedious task to mesh all structure and fluid subdomains within the tube bundle. Few of these methods have nonetheless been implemented in industrial finite element codes. In a previous paper (Sigrist, et al., 2007, “Fluid-Structure Interaction Effects Modeling for the Modal Analysis of a Nuclear Pressure Vessel,” J. Pressure Vessel Technol., 123, pp. 1–6), a homogenization method has been applied to an industrial case for the modal analysis of a nuclear rector with internal structures and coupling effects modeling. The present paper aims at investigating the extension of the proposed method for the dynamic analysis of tube bundles with fluid-structure interaction modeling. The homogenization method is compared with the classical coupled method in terms of eigenfrequencies, eigenmodes, and effective modal masses.


Author(s):  
Junlei Wang ◽  
JingYu Ran ◽  
Lin Ding ◽  
Li Zhang

In this paper, a new method of generating power by “wind-induced vibration” (WIV). A lead zirconate titanate (PZT) beam which has a very high power density is installed on the bluff body which will have WIV with the bluff body has been explored. Both numerical computation and experimental work have been taken to measure the capacity of the power generating system. Two different shapes of bluff bodies have been tested. In numerical section, the lift and drag coefficient and the vortex shedding frequency have been computed to verify how the dimensionless parameter Vr affects the fluid field. An one-degree-freedom system has been added to describe the wind-induced vibration, and the vibrational frequency and amplitude of the vibration have been monitored. The fluid-structure interaction has been solved by a hybrid method of finite volume method (FVM) and finite element method (FEM). From numerical simulation, the conclusions can be given that as the non-dimensionalised mass m* is about 780, the vortex induced vibration (VIV) response of a single cylinder is quite different comparing with Govardhan&Williamson. Then a wind tunnel test has been taken to measure the voltage output of the PZT, and we have gotten a result quite close to the data of numerical method.


Author(s):  
Haym Benaroya ◽  
Timothy Wei

The problem of vortex-shedding from bluff bodies has been examined for over a century, as reflected by the extensive literature on the subject. The focus of these foregoing researches can be split into two broad categories: investigations into the flow characteristics around a body in a flow, and studies of the response of a bluff body to the forces from the flow.


Sign in / Sign up

Export Citation Format

Share Document