• Nuclear Engineering and Technology
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• 제51권2호
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• pp.573-578
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• 2019

Anisotropic distribution of the turbulent kinetic energy and the near-field excitations are the main causes of the steady state Flow-Induced Vibration (FIV) which could lead to fretting wear damage in vertically arranged supported slender rods. In this article, a combined Computational Fluid Dynamics (CFD) and Computational Structural Mechanic (CSM) approach named two-way Fluid-Structure Interaction (FSI) is used to investigate the modal characteristics of a typical rod's vibration. Performance of an Unsteady Reynolds-Average Navier-Stokes (URANS) and Large Eddy Simulation (LES) turbulence models on asymmetric fluctuations of the flow field are investigated. Using the LES turbulence model, any large deformation damps into a weak oscillation which remains in the system. However, it is challenging to use LES in two-way FSI problems from fluid domain discretization point of view which is investigated in this article as the innovation. It is concluded that the near-wall meshes whiten the viscous sub-layer is of great importance to estimate the Root Mean Square (RMS) of FIV amplitude correctly as a significant fretting wear parameter otherwise it merely computes the frequency of FIV.

• 한국전산유체공학회지
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• 제17권1호
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• pp.29-35
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• 2012

Fluid-Structure Interaction analysis of a circular cylinder surrounded by incompressible turbulent flow is presented. The fluid flow is modeled by incompressible Navier-Stokes equations in conjunction with large-eddy simulation for turbulent vortical flows. The circular cylinder is modeled as elastic continuum described by elasto-dynamic equation of motion. Finite element method based approach is utilized for unified formulation of fluid-structure interaction analysis. The magnitude and frequency of structural response is analysed in comparison to the driving fluid forces.

• International Journal of Fluid Machinery and Systems
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• 제6권2호
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• pp.87-93
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• 2013

In order to study the effect of the fluid-structure interaction (FSI) on the simulation results, the external characteristics and internal flow features of a diffuser pump were analyzed with a two-way flow solid coupling method. And the static and dynamic structure analysis of the blade was also caculated with the FEA method. The steady flow field is based on Reynolds Averaged N-S equations with standard $k-{\varepsilon}$ turbulent model, the unsteady flow field is based on the large eddy simulation, and the structure response is based on elastic transient structural dynamic equation. The results showed that the effect of FSI on the head prediction based on CFD really exists. At the same radius, the van mises stress on the nodes closed shroud and hub was larger than other nodes. A large deformation region existed near inlet side at the middle of blades. The strength of impeller satisfied the strength requirement with static stress analysis based on the fourth strength theory. The dynamic stress varied periodically with the impeller rotating. It was also found that the fundamental frequency of the dynamic stress is the rotating frequency and its harmonic frequency. The frequency of maximum stress amplitude at node 1626 was 7 times of the rotating frequency. The frequency of maximum stress amplitude at node 2328 was 14 times of the rotating frequency. No matter strength failure or fatigue failure, the root of blades near shroud is the key region to analyse.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.83-85
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• 2010

A hydraulic gear pump is widely used in many industrial applications to provide both high pressure and high flow rate by physical displacement of finite volume of fluid with each revolution. In this study, two dimensional fluid-structure interaction simulation of gear pump flow was carried out to examine detailed complex flow patterns and structural stress distribution on rotors by using a commercial software ADINA. The effect of rotor clearance size on the flow characteristics, specially the temporal variation of velocity and pressure field, which is a main source of flow noise, also was investigated.

• 동력기계공학회지
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• 제15권6호
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• pp.35-40
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• 2011

The present study aims at investigating the effect of the fluid-structure interaction on the aerodynamic performances in the turbo blower. The design specifications of the reference model driven by 400kW power were given as 7.43kg/s of mass flow rate, 1.66 of pressure ratio with 12000rpm of impeller rotating speed. Numerical simulation has been performed on the three cases based on the tip clearance between the impeller blade and the shroud. The CFX-turbo for flow fields and ANSYS-mechanical for structure domain were applied to solve the present FSI problems inside the turbo blower. Through the numerical results, the performances corrected by the FSI effects were proposed for the more reliable predictions.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.127-153
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• 2012

This paper presents an advanced computational method for the prediction of the responses in the frequency domain of general linear dissipative structural-acoustic and fluid-structure systems, in the low-and medium-frequency domains and this includes uncertainty quantification. The system under consideration is constituted of a deformable dissipative structure that is coupled with an internal dissipative acoustic fluid. This includes wall acoustic impedances and it is surrounded by an infinite acoustic fluid. The system is submitted to given internal and external acoustic sources and to the prescribed mechanical forces. An efficient reduced-order computational model is constructed by using a finite element discretization for the structure and an internal acoustic fluid. The external acoustic fluid is treated by using an appropriate boundary element method in the frequency domain. All the required modeling aspects for the analysis of the medium-frequency domain have been introduced namely, a viscoelastic behavior for the structure, an appropriate dissipative model for the internal acoustic fluid that includes wall acoustic impedance and a model of uncertainty in particular for the modeling errors. This advanced computational formulation, corresponding to new extensions and complements with respect to the state-of-the-art are well adapted for the development of a new generation of software, in particular for parallel computers.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.71-77
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• 2010

As a hybrid model of continuum motion description which combines the advantages of classical kinematical descriptions i.e. Lagrangian and Eulerian description, the ALE (Arbitrary Lagrangian Eulerian) description is adopted for the simulation of a fluid-structure interaction of solid propellant rocket interior. The fluid-structure interaction phenomenon with the deformation of solid domain during the simulation. The developed solver is applied flow and propellant structure. The computed results show complex flow physics in the combustion chamber and the behavior of a solid propellant deformation.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.93-98
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• 2010

One of the most effective key factors to improve performance of automotive reciprocating compressor is the design of suction and discharge reed valves. Reed valves are also the major sources of compressor noise. Valve motion is highly coupled with refrigerant flow. In this study, a process of fluid-structure interaction analysis was developed to predict the cylinder inner flow and the dynamic behavior of valve simultaneously. Interface programs computational structural dynamics code. The full cycle simulations of compressor were performed using FSI analysis was alidated by comparing the simulation results with the experimental results.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 춘계학술대회
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• pp.36-37
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• 2014

It is necessary to develop highly sophisticated Modeling & Simulation (M&S) system for the scientific investigation of marine accident causes and for the systematic reproduction of accidental damage procedure. To ensure an accurate and reasonable prediction of marine accidental causes, such as collision, grounding and flooding, full-scale ship M&S simulations would be the best approach using hydrocode, such as LS-DYNA code, with its Fluid-Structure Interaction (FSI) analysis technique. The objectivity of this paper is to present three full-scale ship collision, grounding and flooding simulation results of marine accidents, and to show the possibility of the scientific investigation of marine accident causes using highly sophisticated M&S system.

• Ocean Systems Engineering
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• 제7권3호
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• pp.299-318
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• 2017

The paper aims at illustrating several key issues and ongoing efforts for development of a reliable fully-Lagrangian particle-based solver for simulation of hydroelastic slamming. Fluid model is founded on the solution of Navier-Stokes along with continuity equations via an enhanced version of a projection-based particle method, namely, Moving Particle Semi-implicit (MPS) method. The fluid model is carefully coupled with a structure model on the basis of conservation of linear and angular momenta for an elastic solid. The developed coupled FSI (Fluid-Structure Interaction) solver is applied to simulations of high velocity impact of an elastic aluminum wedge and hydroelastic slammings of marine panels. Validations are made both qualitatively and quantitatively in terms of reproduced pressure as well as structure deformation. Several remaining challenges as well as important key issues are highlighted. At last, a recently developed multi-scale MPS method is incorporated in the developed FSI solver towards enhancement of its adaptivity.