Fluid-Structure Interaction in Waterhammer Response of Flexible Piping

1986 ◽  
Vol 108 (3) ◽  
pp. 249-255 ◽  
Author(s):  
T. Belytschko ◽  
M. Karabin ◽  
J. I. Lin
Keyword(s):  
Structural Model ◽  
Fluid Structure Interaction ◽  
Added Mass ◽  
Piping System ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Piping Systems ◽  
Thin Walled ◽  
Fully Coupled ◽  
Recovery Procedure

In the waterhammer analysis of piping systems, incompressible (or added mass) representations are generally used in computing the response of the piping. It is shown that this procedure is not necessarily conservative, particularly for thin-walled, flexible piping systems, and that fully coupled fluid-structure solutions can predict higher loads and stresses. A modal recovery procedure which easily permits the representation on the acoustic effects of the fluid to be included in a structural model is also presented. Results are given for both simple models and a piping system from an LMFBR design.

Frequency Domain Analysis of Vibrations in Liquid-Filled Piping Systems

1999 ◽  
Author(s):  
Zongxia Jiao ◽  
Qing Hua ◽  
Kai Yu
Keyword(s):  
Frequency Domain ◽  
Transfer Matrix ◽  
Fluid Structure Interaction ◽  
Viscous Friction ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Piping System ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Piping Systems

Abstract In the analysis of liquid-filled piping systems there are Poisson-coupled axial stress waves in the pipe and liquid column, which are caused by the dilation of the pipe. In some conditions the influence of viscous friction that is usually frequency-dependent should not be omitted, which in fact is another kind of coupled form. It directly influences the amplitude of vibration of piping systems to some degree. The larger the viscosity of the liquid is, the greater the influence will be. Budny (1991) included the viscous friction influence in time domain analysis of fluid-structure interaction, but did not give frequency domain analysis. Lesmez (1990) gave the model analysis liquid-filled piping systems without considering friction. If the friction is not included in frequency domain analysis, the vibration amplitude will be greater than that when friction is included, especially at harmony points, cause large errors in the simulation of fluid pipe network analysis, although it may have little influence on the frequency of harmony points. The present paper will give detail solutions to the transfer matrix that represents the motion of single pipe section, which is the basis of complex fluid-structure interaction analysis. Combined with point matrices that describe specified boundary conditions, overall transfer matrix for a piping system can be assembled. Corresponding state vectors can then be evaluated to predict the piping and liquid motion. At last, a twice-coordinate transformation method is adopted in joint coupling. Consequently, the vibration analysis of spatial liquid-filled piping systems can be carried out. It is proved to be succinct, valid and versatile. This method can be extended to the simulation of the curved spatial pipeline systems.

Response of Water-Filled Thin-Walled Pipes to Pressure Pulses: Experiments and Analysis

1980 ◽  
Vol 102 (1) ◽  
pp. 56-61 ◽  
Author(s):  
C. M. Romander ◽  
L. E. Schwer ◽  
D. J. Cagliostro
Keyword(s):  
Pressure Pulse ◽  
Fluid Structure Interaction ◽  
Two Dimensional ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Modeling Techniques ◽  
Pressure Pulses ◽  
Piping Systems ◽  
Dimensional Finite Element ◽  
Thin Walled

Experiments are performed to verify modeling techniques used in fluid-structure interaction codes that predict the response of liquid-filled piping systems to strong pressure pulses. Pressure pulses having a 150-μs rise time, a 2000-psi (13.8 MPa) magnitude, and a 3-ms duration are propagated into straight, water-filled Ni 200 pipes (3-in. (7.6-cm) O.D. 0.065-in. (0.165-cm) wall). Attenuation of the pressure pulse and the strain and deformation along the pipes are measured. The experiments are modeled in WHAM, a two-dimensional, finite-element, compressible fluid-structure interaction code. The experimental and analytical results are discussed in detail and are found to compare favorably.

Free Vibration and Thermal Fluid Structure Interaction Simulation of Functionally Graded Pipe by Modeling As Layered Structure

2020 ◽  
Author(s):  
Ziyi Su ◽  
Kazuaki Inaba ◽  
Amit Karmakar ◽  
Apurba Das
Keyword(s):  
Free Vibration ◽  
Layered Structure ◽  
Volume Fraction ◽  
Fluid Structure Interaction ◽  
Functionally Graded ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Layered Model ◽  
Piping Systems ◽  
Complex Phenomena

Abstract Functionally graded materials (FGMs) are advanced class of composite materials which can be used as the thermal barrier to protect inner components from the outside high temperature environment. In FGMs, the volume fraction of each constituent can be tailored made across the thickness for desired applications. In this work, the simulation of FGMs in pipes is considered. Despite the wide application of pipes in machinery, those pipes would suffer from many safety problems, such as thermal stress, cavitation, fracture etc. Application of FGMs to the piping systems could lead to some new solutions accounting for safety measures and higher service life. However, the complex phenomena within the fluid structure interaction are hard to describe with the theoretical solution. The visualization of results from simulation will be helpful in understanding the distribution of kinds of physical quantities within the concerned model. For the simulation, FGMs are modeled as the layered structure in the standard finite element method (FEM) package based on FGM constituent law. The free vibration of the FG pipe is simulated and the accuracy of layered model is verified by numerical calculations. Further, based on the layered model, conjugate heat transfer simulations in a heat exchanger with FGMs are conducted.

Optimization of Vibration Reduction in a Helicopter Blade With 2 Way Fluid-Structure Interaction

2018 ◽  
Author(s):  
Mürüvvet Sinem Sicim ◽  
Metin Orhan Kaya
Keyword(s):  
Cantilever Beam ◽  
Fiber Orientation ◽  
Structural Model ◽  
Fiber Composite ◽  
Vibration Reduction ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Helicopter Blade ◽  
Structure Interaction ◽  
Blade Model

The main goal of this study is the optimization of vibration reduction on helicopter blade by using macro fiber composite (MFC) actuator under pressure loading. Due to unsteady aerodynamic conditions, vibration occurs mainly on the rotor blade during forward flight and hover. High level of vibration effects fatigue life of components, flight envelope, pleasant for passengers and crew. In this study, the vibration reduction phenomenon on helicopter blade is investigated. 3D helicopter blade model is used to perform the aeroelastic behavior of a helicopter blade. Blade design is created by Spaceclaim and finite element analysis is conducted by ANSYS 19.0. Generated model are solved via Fluent by using two-way fluid-solid coupling analysis, then the analyzed results (all aerodynamic loads) are directly transferred to the structural model. Mechanical results (displacement etc.) are also handed over to the Fluent analysis by helping fluid-structure interaction interface. Modal and harmonic analysis are performed after FSI analysis. Shark 120 unmanned helicopter blade model is used with NACA 23012 airfoil. The baseline of the blade structure consists of D spar made of unidirectional Glass Fiber Reinforced Polymer +45°/−45° GFRP skin. MFC, which was developed by NASA’s Langley Research Center for the shaping of aerospace structures, is applied on both upper and lower surfaces of the blade to reduce the amplitude in the twist mode resonant frequency. D33 effect is important for elongation and to observe twist motion. To foresee the behavior of the MFC, thermo-elasticity analogy approach is applied to the model. Therefore, piezoelectric voltage actuation is applied as a temperature change on ANSYS. The thermal analogy is validated by using static behavior of cantilever beam with distributed induced strain actuators. Results for cantilever beam are compared to experimental results and ADINA code results existing in the literature. The effects of fiber orientation of MFC actuator and applied voltage on vibration reduction on helicopter blade are represented. The study shows that torsion mode determines the optimum placement of actuators. Fiber orientation of the MFC has few and limited influences on results. Additionally, the voltage applied on MFC has strong effects on the results and they must be selected according to applied model.

Study on Similar Skills of Dynamic Model Test Concerning Fluid-Structure Interaction for Water-Conveyance Tunnel in Soft Soil

2010 ◽  
Vol 29-32 ◽  
pp. 1458-1463 ◽  
Author(s):  
Jin Yun Liu ◽  
Jian Yun Chen
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Structural Model ◽  
Soft Soil ◽  
Fluid Structure Interaction ◽  
Similar Relationship ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Water Conveyance ◽  
Water Conveyance Tunnel

Three basic types of similar relationship between the prototype and the model for dynamic structural model test and dynamic destructive model test were proposed in corresponding literatures. At the time the situation where various similar relationships are applicable and the technique to ensure similarity for the different goal was discussed. Here the numerical simulation of model test of water-conveyance tunnel concerning fluid-structure interaction in soft soil is studied. Based on economy and practicability of selective material for model test, the similar relationship and the technique are proposed, which are validated through the example. The results of numerical simulation show: under the specific conditions, data of the model test can completely transfer to those of the prototype by use of this type of similar skill, and get more useful information. Some new ideas are introduced to keep the similarity of the hydro-structure structures.

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