• Title/Summary/Keyword: Coupled numerical analysis

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AN APPROXIMATE ANALYTICAL SOLUTION OF A NONLINEAR HYDRO-THERMO COUPLED DIFFUSION EQUATION

  • Lee, Jeong-woo;Cho, Won-cheol
    • Water Engineering Research
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    • v.2 no.3
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    • pp.187-196
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    • 2001
  • An approximate analytical solution of a nonlinear hydro-thermo coupled diffusion equation is derived using the dimensionless form of the equation and transformation method. To derive an analytical solution, it is drastically assumed that the product of first order derivatives in the non-dimensionalized governing equation has little influence on the solution of heat and moisture behavior problem. The validity of this drastic assumption is demonstrated. Some numerical simulation is performed to investigate the applicability of a derived approximate analytical solution. The results show a good agreement between analytical and numerical solutions. The proposed solution may provide a useful tool in the verification process of the numerical models. Also, the solution can be used for the analysis of one-dimensional coupled heat and moisture movements in unsaturated porous media.

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Numerical Modeling of Perturbation Effects of Electrostatic Probe into 2D ICP(inductively coupled plasma) (2D-ICP(inductively coupled plasma)에서 정전 탐침 삽입 시의 플라즈마 수치 계산)

  • Joo, Jung-Hoon
    • Journal of the Korean institute of surface engineering
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    • v.44 no.1
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    • pp.26-31
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    • 2011
  • Numerical modeling is used to investigate the perturbation of a single Langmuir probe (0.2 mm diameter shielded with 6 mm insulator) inserted along the center axis of a cylindrical inductively coupled plasma chamber filled with Ar at 10 mTorr and driven by 13 MHz. The probe was driven by a sine wave. When the probe tip is close to a substrate by 24.5 mm, the probe characteristics was unperturbed. At 10 mm above the substrate, the time averaged electric potential distribution around the tip was severly distorted making a normal probe analysis impossible.

Moving Least Squares Interface Welding Method for Coupled Analysis of Independently Modeled Finite Element Substructures (독립적으로 모델링된 유한요소 부분구조물 시스템의 통합 연계해석을 위한 이동최소자승 정계접합법의 개발)

  • An, Jae-Mo;Song, You-Me;Choi, Dong-Whan;Cho, Jin-Yeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.10
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    • pp.26-34
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    • 2005
  • In this paper, a novel moving least squares interface welding method is proposed to carry out the coupled analysis of whole model composed of independently modeled finite element substructures with nodal mismatching interfaces. To verify the validity, and efficiency of the proposed interface welding method, various numerical examples are worked out including patch tests, convergence tests, and examples of coupled analyses of the structural systems with mismatching substructures. From the numerical tests, it is confirmed that one can efficiently carry out the coupled analysis of whole model composed of mismatching finite element substructures through the proposed method without any remeshing or any additional unknown.

Dynamic Analysis of Asymmetric Bending-torsion Coupled Beam Using Exact Dynamic Elements (엄밀한 동적 요소를 이용한 비대칭 굽힘-비틀림 연성 보의 동적 해석)

  • Hong, Seong-Uk;Gang, Byeong-Sik;Jo, Yong-Ju
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.8
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    • pp.87-95
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    • 2001
  • Although asymmetric beams are widely used in industry, few research results are available on the dynamic modeling and analysis of structure including asymmetric beams. Asymmetric beams cause complicated vibration phenomena due to the inherent bending-torsion coupled vibration. In this paper, an exact dynamic element matrix for the bending-torsion coupled vibration of asymmetric beam is derived. The application of the derived exact dynamic element matrix is demonstrated by some illustrative examples wherein the natural frequencies by the proposed modeling method are compared with those available in the literature. Another numerical example is also illustrated which deals with a general beam with joints. The numerical study shows that the exact dynamic element model is useful for the dynamic analysis of asymmetric bending-torsion coupled beams.

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Computational analysis of coupled fluid-structure for a rotor blade in hover (정지 비행하는 로터 블레이드의 전산 유체-구조 결합 해석)

  • Kim, Hae-Dong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.12
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    • pp.1139-1145
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    • 2008
  • numerical study on the coupled fluid-structure for a rotor blade in hover was conducted. Computational fluid dynamics code with enhanced wake-capturing capability is coupled with a simple structural dynamics code based on Euler-Bernoulli's beam equation. The numerical results show a reasonable blade structural deformation and aerodynamic characteristics.

COMPONENT AND SYSTEM MULTI-SCALE DIRECT-COUPLED CODE IMPLEMENTATION USING CUPID AND MARS CODES (CUPID 코드와 MARS 코드를 이용한 기기/계통 다중스케일 연계 해석 코드 구현)

  • Park, I.K.
    • Journal of computational fluids engineering
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    • v.21 no.3
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    • pp.89-97
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    • 2016
  • In this study, direct code coupling, in which two codes share a single flow field, was conducted using 3-dimensional high resolution thermal hydraulics code, CUPID and 1-dimensional system analysis code, MARS. This approach provide the merit to use versatile capability of MARS for nuclear power plants and 3-dimensional T/H analysis capability of CUPID. Numerical Method to directly couple CUPID and MARS was described in this paper. The straight flow and manometer flow oscillation were calculated to verify conservation of coupled CUPID/MARS code in mass, momentum, and energy. This verification calculations indicates that the CUPID/MARS is coupled appropriately in numerical aspect and the coupled code can be applied to nuclear reactor thermal hydraulics after validation against integral transient experiments.

Exact Solutions for Bending-Torsion Coupled Vibration of Composite Timoshenko Beam (복합재 티모센코 보의 굽힘 비틀림 연성 진동에 대한 엄밀해)

  • Hong, Seong-Uk;Gang, Byeong-Sik;Park, Jung-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1559-1566
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    • 2001
  • This paper proposes a dynamic analysis method for obtaining exact solutions of composite Timoshenko beams, which are inherently subjected to both the bending , and torsional vibrations. In this paper, the bending-torsion coupled vibration of composite Timoshenko beam is rigorously modelled and analyzed. Two numerical examples are provided to validate and illustrate the bending-torsion coupled vibration of composite Timoshenko beam structure. The numerical examples prove that the proposed method is of great use for the dynamic analysis of dynamic structures composed of multiply connected composite Timoshenko beams.

Coupled Analysis of Heat Transfer, Fluid Flow and Solidification in the Filling of Castings (용탕충진과정에 있어서 열 및 유동을 포함한 2차원 응고해석)

  • Kim, Sung-Bin;Cho, In-Sung;Kim, Jin-Su;Hong, Chun-Pyo
    • Journal of Korea Foundry Society
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    • v.13 no.5
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    • pp.424-431
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    • 1993
  • A Numerical technique has been developed for the coupled heat transfer and fluid flow calculation during the casting process. In this method the SMAC technique was coupled with the concept of Volume of Fluid(VOF) to calculate melt free surface and velocity profiles within the melt, and the Energy Marker method coupled with the finite difference method was proposed for the convective and conductive heat transfer analysis in the casting. When comparing numerical calculations with experimental observations, a close correlation was evident. It has been shown that this technique is useful for proper gating and casting design, especially for thin-walled castings.

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Numerical Modeling of Floating Electrodes in a Plasma Processing System

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • v.24 no.4
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    • pp.102-110
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    • 2015
  • Fluid model based numerical analysis is done to simulate a plasma processing system with electrodes at floating potential. $V_f$ is a function of electron temperature, electron mass and ion mass. Commercial plasma fluid simulation softwares do not provide options for floating electrode boundary value condition. We developed a user subroutine in CFD-ACE+ and compared four different cases: grounded, dielectric, zero normal electric field and floating electric potential for a 2D-CCP (capacitively coupled plasma) with a ring electrode.

Numerical Analysis of Floating-Body Motions in Varying Bathymetry

  • Kim, Taeyoung;Kim, Yonghawn
    • International Journal of Ocean System Engineering
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    • v.4 no.1
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    • pp.43-48
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    • 2014
  • Varying bathymetry significantly affects on the wave propagation and motion response of floating body. Coupled-mode wave theory is adopted to describe the incident wave properly in varying region. The results of waves and motion response are compared to those from numerical wave tank, and the agreement is favorable. The sloped bottom is modeled and its effect on the floating body is discussed.