• Title/Summary/Keyword: fluid element

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Development of CAE tool for reducing vibration of pipe-mount system conveying fluid (유동이 있는 배관-마운트 계의 진동저감설계 CAE Tool개발)

  • Lee, Seong-Hyeon;Jeon, Su-Hong;Jeong, Weui-Bong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.472-473
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    • 2008
  • In this research, the finite element model is formulated taking into consideration of the effects of the fluid flow in a pipe. The characteristic of vibration is presented using mass, damping and stiffness matrix in the finite element equation of this pipe system. The displacement distribution of pipe system caused by fluid force is discussed. The method for optimizing the location of mount and the value of mount stiffness to reduce the vibration of pipe system is introduced.

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Mount design to reduce the vibration of pipe system conveying fluid (유체를 운반하는 배관계의 진동 저감을 위한 마운트 설계)

  • Lee, Seong-Hyeon;Jeong, Weui-Bong;Jeong, Cheol-Ung;Ham, Il-Bae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1437-1441
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    • 2007
  • This paper formulates the finite element model is formulated taking into consideration of the effects of the fluid flow in a pipe. The characteristic of vibration is presented using mass, damping and stiffness matrix in the finite element equation of this pipe system. The displacement distribution of pipe system caused by fluid force is discussed. The variation of vibration of a pipe system according the change of mount stiffness is discussed.

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Numerical Analysis of Vibration Characteristics in Deep Water Tank (수치해석에 의한 심수 탱크구조물의 진동에 관한 연구)

  • 배성용
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.10
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    • pp.791-797
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    • 2003
  • A liquid storage rectangular tank structures are used In many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks In contact with Inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine or propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. In the previous report, we have developed numerical tool of vibration analysis of 3-dimensional tank structure using finite elements for plates and boundary elements for fluid region. In the present report, using the numerical analysis, vibrations characteristics In deep water tank are investigated and discussed.

MOMENT-OF-FLUID METHOD FOR FREE SURFACE FLOW SIMULATION USING UNSTRUCTURED MESHES (비정렬 격자상에서 Moment-of-Fluid 방법을 이용한 자유표면유동계산)

  • Ahn, H.T.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.65-67
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    • 2011
  • The moment-of-fluid (MOF) method is a new volume-tracking method that accurately treats evolving material interfaces. The MOF method uses moment data, namely the material volume fraction, as well as the centroid, for a more accurate representation of the material configuration, interfaces and concomitant volume advection. In this paper, unstructured mesh extension of the MOF method is to be presented. The MOF method is coupled with a stabilized finite element incompressible Navier-Stokes solver for two materials. The effectiveness of the MOF method is demonstrated with a free-surface dam-break problem.

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Numerical Analysis of Vibration Characteristics in Deep Water Tank (수치해석에 의한 심수 탱크구조물의 진동에 관한 연구)

  • 배성용;홍봉기;배동명
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.1079-1084
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    • 2003
  • A liquid storage rectangular tank structures are used in many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks in contact with inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks ill contact with fluid near engine or propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. In the previous report, we have developed numerical tool of vibration analysis of 3-dimensional tank structure using finite elements for plates and boundary elements for fluid region. In the present report, using the numerical analysis, vibrations characteristics in deep water tank are investigated and discussed.

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Development of a New Analysis Method of Fluid Film for Efficient Estimate of the Moving Characteristics of Hydrostatic Bearings (유정압베어링 운동특성의 효과적인 예측을 위한 새로운 유막 해석방법의 개발)

  • 전상렬;김권희
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.8
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    • pp.166-174
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    • 2003
  • Hydrostatic bearings are widely used in precision machines due to their high motion guide accuracy, low friction and high load carrying capacity. It is very useful to estimate the moving characteristics of hydrostatic bearings in the design stage. A new method is suggested for the analysis of fluid film in hydrostatic bearings. A combined mesh of 8 node solid elements with negligible deformation resistance and spring-dashpot elements is used in conjunction with the user subroutine of ABAQUS to represent the fluid film. The mesh can be used to capture the deformation of the bearing structure as well as the varying properties of fluid film. Analysis results from the finite element model are compared with theoretical solutions, results from FLUENT analysis and some previous works. With this method, static and dynamic analyses of the system containing the bearings can be performed efficiently.

Dynamic Analysis of Rectangular Liquid Storage Containers Considering Fluid-Structure Interaction effects (유체-구조물 상호작용 효과를 고려한 직사각형 단면의 수조구조물의 동적 해석)

  • 박장호;권기준
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.96-101
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    • 2000
  • The effects of internal fluid motion have to be considered in the analysis of liquid storage containers. Therefore this thesis developed a three-dimensional boundary element-finite element method for the analysis of rectangular liquid storage containers. The irrotational motion of inviscid and incompressible ideal fluid is modeled by using boundary elements and the motion of structure by finite elements. Coupling is performed by using compatibility and equilibrium conditions along the interface. Dynamic response characteristics of rectangular liquid storage containers such as sloshing motion, hydrodynamic pressure, displacement by fluid-structure interaction are investigated.

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Forced vibration analysis of a dam-reservoir interaction problem in frequency domain

  • Keivani, Amirhossein;Shooshtari, Ahmad;Sani, Ahmad Aftabi
    • Coupled systems mechanics
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    • v.3 no.4
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    • pp.385-403
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    • 2014
  • In this paper, the forced vibration problem of an Euler-Bernoulli beam that is joined with a semi-infinite field of a compressible fluid is considered as a boundary value problem (BVP). This BVP includes two partial differential equations (PDE) and some boundary conditions (BC), which are introduced comprehensively. After that, the closed-form solution of this fluid-structure interaction problem is obtained in the frequency domain. Some mathematical techniques are utilized, and two unknown functions of the BVP, including the beam displacement at each section and the fluid dynamic pressure at all points, are attained. These functions are expressed as an infinite series and evaluated quantitatively for a real example in the results section. In addition, finite element analysis is carried out for comparison.

Finite Element Analysis for Evaluation of Viscous and Eccentricity Effects on Fluid Added Mass and Damping (유체 부가질량 및 감쇠 결정시 점성 및 편심 영향에 대한 유한요소해석)

  • 구경회;이재한
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.2
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    • pp.21-27
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    • 2003
  • In general, simple fluid added mass method is used for the seismic and vibration analysis of the immersed structure to consider the fluid-structure interaction effect. Actually, the structural response of the immersed structure can be affected by both the fluid added mass and damping caused by the fluid viscosity. These variables appeared as a consistent matrix form with the coupling terms. In this paper, finite element formula for the inviscid fluid case and viscous fluid case are derived from the linearized Navier Stoke's equations. Using the finite element program developed in this paper, the analyses of fluid added mass and damping for the hexagon core structure of the liquid metal reactor are carried out to investigate the effect of fluid viscosity with variation of the fluid gap and Reynolds number. From the analysis results, it is verified that the viscosity significantly affects the fluid added mass and damping as the fluid gap size decrease. From the analysis results of eccentricity effect on the fluid added mass and damping of the concentric cylinders, the fluid added mass increase as the eccentricity increases, however the fluid damping increases only when the eccentricity is very severe.