A special numerical method for fluid-structure interaction problems subjected to explosion and impact loading

2020 ◽  
Vol 63 (7) ◽  
pp. 1280-1292
Author(s):  
JianGuo Ning ◽  
FanLin Meng ◽  
TianBao Ma ◽  
XiangZhao Xu
Keyword(s):  
Numerical Method ◽  
Impact Loading ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction

Experimental and Numerical Analysis for Fluid-Structure Interaction for an Enclosed Hexagonal Assembly

2014 ◽  
Author(s):  
Lucia Sargentini ◽  
Benjamin Cariteau ◽  
Morena Angelucci
Keyword(s):  
Numerical Method ◽  
Stokes Equations ◽  
Interaction Analysis ◽  
Flow Behavior ◽  
Fluid Structure Interaction ◽  
Water Injection ◽  
Free Vibrations ◽  
Navier Stokes ◽  
Fluid Structure ◽  
Structure Interaction

This paper is related to fluid-structure interaction analysis of sodium cooled fast reactors core (Na-FBR). Sudden liquid evacuation between assemblies could lead to overall core movements (flowering and compaction) causing variations of core reactivity. The comprehension of the structure behavior during the evacuation could improve the knowledge about some SCRAMs for negative reactivity occurred in PHÉNIX reactor and could contribute on the study of the dynamic behavior of a FBR core. An experimental facility (PISE-2c) is designed composed by a Poly-methyl methacrylate hexagonal rods (2D-plan similitude with PHÉNIX assembly) with a very thin gap between assemblies. Another experimental device (PISE-1a) is designed and composed by a single hexagonal rod for testing the dynamic characteristics. Different experiments are envisaged: free vibrations and oscillations during water injection. A phenomenological analysis is reported showing the flow behavior in the gap and the structure response. Also computational simulations are presented in this paper. An efficient numerical method is used to solve Navier-Stokes equations coupled with structure dynamic equation. The numerical method is verified by the comparison of analytic models and experiments.

scholarly journals Fully Coupled Smoothed Particle Hydrodynamics-Finite Element Method Approach for Fluid–Structure Interaction Problems With Large Deflections

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
A. Ersin Dinçer ◽  
Abdullah Demir ◽  
Zafer Bozkuş ◽  
Arris S. Tijsseling
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Smoothed Particle Hydrodynamics ◽  
Fluid Structure Interaction ◽  
Elastic Structure ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

Abstract In this study, a combination of the smoothed particle hydrodynamics (SPH) and finite element method (FEM) solving the complex problem of interaction between fluid with free surface and an elastic structure is studied. A brief description of SPH and FEM is presented. Contact mechanics is used for the coupling between fluid and structure, which are simulated with SPH and FEM, respectively. In the proposed method, to couple mesh-free and mesh-based methods, fluid and structure are solved together by a complete stiffness matrix instead of iterative predictive–corrective or master–slave methods. In addition, fully dynamic large-deformation analysis is carried out in FEM by taking into account mass and damping of the elastic structure. Accordingly, a two-dimensional fluid–structure interaction (FSI) code is developed and validated with two different experiments available in the literature. The results of the numerical method are in good agreement with the experiments. In addition, a novel laboratory experiment on a dam break problem with elastic gate in which the length of the initial water column is larger than its height is conducted. The main difference between the previous experiments and the one conducted in this study is that an upward water motion parallel to the elastic gate is observed at the upstream side of the gate. This motion is captured with the numerical method.

Multiphysics Study of Structural Impact to Fluidic Media

2011 ◽  
Vol 673 ◽  
pp. 1-10 ◽  
Author(s):  
Matej Vesenjak ◽  
Zoran Ren ◽  
Mojtaba Moatamedi
Keyword(s):  
Impact Loading ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Water Impact ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Particle Hydrodynamics ◽  
Ale Methods ◽  
Smoothed Particle ◽  
Space Capsule

The paper presents a fluid structure interaction based numerical study of impact loading for a hemispherical structure upon water and a space capsule water landing. The study has a strong relevance in the determination of the crashworthiness of aerospace structures upon water impact loading. Finite element based numerical techniques have been used for the analysis of the underlying transient dynamic and fluid-structure interaction. Smoothed Particle Hydrodynamics (SPH) and Arbitrary Lagrange-Eulerian (ALE) methods have been used to simulate the behaviour of the fluid (water) under impact conditions. The accelerations and velocities of the impacting objects have been validated with by experimental measurements and analytical results. Numerical analyses showed a strong potential for the use of developed computational fluid structure interaction models for analyses of water impact loading related problems.

Godunov’s Method for Simulatinons of Fluid-Structure Interaction in Piping Systems

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Janez Gale ◽  
Iztok Tiselj
Keyword(s):  
Mathematical Model ◽  
Numerical Method ◽  
Constant Coefficient ◽  
Single Phase ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Godunov’S Method ◽  
Piping Systems ◽  
Godunov′S Method

Constant coefficient one-dimensional linear hyperbolic systems of partial differential equations (PDEs) are often used for description of fluid-structure interaction (FSI) phenomena during transient conditions in piping systems. In the past, these systems of equations have been numerically solved with method of characteristics (MOCs). The MOC method is actually the most efficient and accurate method for description of the single-phase transient in the cold liquid where the constant coefficient mathematical model describes phenomenon with sufficient accuracy. In energy production systems where hot pressurized liquid is used for heat transfer between the heat source and the steam generator, more complex and nonlinear mathematical models are needed to describe transient flow and these models cannot be solved with MOC method because the models are not constant. In addition, the MOC method can be used for pipes having discontinuities like elbows, geometrical changes, material properties changes, etc., but only with some extra numerical modeling. An interesting alternative is explicit characteristic upwind numerical method, known as Godunov’s method that is frequently used for nonlinear systems or systems where properties change with position. In the present study, applicability of the Godunov’s method for the FSI analyses is tested with eight first order PDEs mathematical model. The conventional linear mathematical model is improved with convective term that makes the system nonlinear and additional terms that enable simulations of the FSI in arbitrarily shaped piping systems located in a plane. Two PDEs describe pressure waves in the single-phase fluid and six PDEs describe axial, lateral, and rotational stress waves in the pipe. The applied system of equations has stiff source terms. This numerical problem is solved introducing implicit iterations. The proposed model is verified with a rod impact experiment that is carried out on single-elbow pipe hanging on wires. Godunov’s method is found as a very promising numerical method for simulations of the FSI problems.

Forced Response Analyses of Mistuned Radial Inflow Turbines

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Thomas Giersch ◽  
Peter Hönisch ◽  
Bernd Beirow ◽  
Arnold Kühhorn
Keyword(s):  
Numerical Method ◽  
Fluid Structure Interaction ◽  
Industrial Applications ◽  
Forced Response ◽  
Blade Vibration ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Damping ◽  
Radial Turbine ◽  
Spiral Casing

Radial turbine wheels designed as blade integrated disks (blisk) are widely used in various industrial applications. However, related to the introduction of exhaust gas turbochargers in the field of small and medium sized engines, a sustainable demand for radial turbine wheels has come along. Despite those blisks being state of the art, a number of fundamental problems, mainly referring to fluid-structure-interaction and, therefore, to the vibration behavior, have been reported. Aiming to achieve an enhanced understanding of fluid-structure-interaction in radial turbine wheels, a numerical method, able to predict forced responses of mistuned blisks due to aerodynamic excitation, is presented. In a first step, the unsteady aerodynamic forcing is determined by modeling the spiral casing, the stator vanes, and the rotor blades of the entire turbine stage. In a second step, the aerodynamic damping induced by blade vibration is computed using a harmonic balance technique. The structure itself is represented by a reduced order model being extended by aerodynamic damping effects and aerodynamic forcings. Mistuning is introduced by adjusting the modal stiffness matrix based on results of blade by blade measurements that have been performed at rest. In order to verify the numerical method, the results are compared with strain-gauge data obtained during rig-tests. As a result, a measured low engine order excitation was found by modeling the spiral casing. Furthermore, a localization phenomenon due to frequency mistuning could be proven. The predicted amplitudes are close to the measured data.

Forced Response Analyses of Mistuned Radial Inflow Turbines

2012 ◽  
Author(s):  
Thomas Giersch ◽  
Peter Hönisch ◽  
Bernd Beirow ◽  
Arnold Kühhorn
Keyword(s):  
Numerical Method ◽  
Fluid Structure Interaction ◽  
Industrial Applications ◽  
Forced Response ◽  
Blade Vibration ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Damping ◽  
Radial Turbine ◽  
Spiral Casing

Radial turbine wheels designed as blade integrated disks (blisk) are widely used in various industrial applications. However, related to the introduction of exhaust gas turbochargers in the field of small and medium sized engines a sustainable demand for radial turbine wheels has come along. Despite those blisks are state of the art, a number of fundamental problems, mainly referred to fluid-structure-interaction and therefore to the vibration behavior, have been reported. Aiming to achieve an enhanced understanding of fluid-structure-interaction in radial turbine wheels a numerical method, able to predict forced responses of mistuned blisks due to aerodynamic excitation, is presented. In a first step the unsteady aerodynamic forcing is determined by modeling the spiral casing, the stator vanes and the rotor blades of the entire turbine stage. In a second step the aerodynamic damping induced by blade vibration is computed using a harmonic balance technique. The structure itself is represented by a reduced order model being extended by aerodynamic damping effects and aerodynamic forcings. Mistuning is introduced by adjusting the modal stiffness matrix based on results of blade by blade measurements that have been performed at rest. In order to verify the numerical method, the results are compared with strain-gauge data obtained during rig-tests. As a result a measured low engine order excitation was found by modeling the spiral casing. Furthermore a localization phenomenon due to frequency mistuning could be proven. The predicted amplitudes are close to measured data.

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