Modal Analysis on Fluid–Structure Interaction System of a Large-Scale Gas Control Valve

2011 ◽  
Vol 305 ◽  
pp. 15-18
Author(s):  
Fang Cao ◽  
Yong Wang

According to the real structure and work condition of a large-scale gas control valve used in recycling generating electricity project, a modal analysis modeling of fluid-structure interaction system is set up and the vibration in fluid-structure interaction is studied. The fluid force on the valve plug when the control valve at different openings is analyzed. According to the modal computing of the plug in fluid environment, the vibration frequencies of the plug are obtained. The influence on vibration frequency of fluid-structure interaction is showed, which relate to vibration modal of plug. The change of plug frequency at coupling and uncoupling condition is investigated. All of these are in favor of vibration characteristic analysis, vibration fault diagnosis of control valve system and realizing design optimization in plug dynamic characteristics. These are of great practical significance for advancing study on large-scale control valves.

2010 ◽  
Vol 455 ◽  
pp. 146-150
Author(s):  
Fang Cao ◽  
Yong Wang ◽  
Y.T. An

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.


Author(s):  
Oded Gottlieb ◽  
Michael Feldman ◽  
Solomon C. S. Yim

Abstract Analysis of a nonlinear friction damping mechanism in a fluid-structure interaction system is performed by combining a generalized averaging procedure with a recently developed identification algorithm based on the Hilbert transform. The system considered includes a nonlinear restoring force and a nonlinear dissipation force incorporating both viscous and structural damping. Frequency and damping response backbone curves obtained from simulated data are compared with analytical and approximate solutions and are found to be accurate. An example large scale experiment exhibiting viscous and Coulomb damping is also analyzed resulting in identification of system parameters.


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

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.


Author(s):  
Gudrun Mikota ◽  
Rainer Haas ◽  
Evgeny Lukachev

Fluid-structure interaction in a bent pipeline is investigated by modal methods. Measured frequency response functions between flow rate excitation and pressure response indicate a coupling effect near the third pipeline resonance. Using modal coordinates for the hydraulic and the mechanical subsystems, a two-degrees-of-freedom study of resonance coupling is carried out. An experimental modal analysis of the coupled hydraulic-mechanical system confirms the predicted resonance splitting; it illustrates the coupling mechanism and shows the relevant mechanical part. An analytical fluid-structure interaction model succeeds in reproducing the measured coupling effect. This model is also used for modification prediction; it demonstrates that an appropriate assembly of mass and damping on the pipeline can help to reduce hydraulic resonance amplitudes.


2015 ◽  
Vol 84 ◽  
pp. 19-28 ◽  
Author(s):  
Tahar Berrabah Amina ◽  
Belharizi Mohamed ◽  
Laulusa André ◽  
Bekkouche Abdelmalek

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