• Title/Summary/Keyword: Numerical method

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Numerical Analysis of Violent Sloshing Problems by CCUP Method (CCUP 기법을 이용한 2 차원 슬로싱 문제의 수치해석)

  • Yang, Kyung-Kyu;Kim, Yong-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.1
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    • pp.1-10
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    • 2010
  • In the present paper, a numerical method based on the constraint interpolation profile (CIP) method is applied for simulating two-dimensional violent sloshing problems. The free surface boundary value problem is considered as a multiphase problem which includes water and air. A stationary Cartesian grid system is adopted, and an interface capturing method is used to trace the shape of free surface profile. The CIP combined unified procedure (CCUP) scheme is applied for flow solver, and the tangent of hyperbola for interface capturing (THINC) scheme is used for interface capturing. Numerical simulations have been carried out for partially-filled 2D tanks under forced sway and roll motions at various filling depths and frequencies. The computational results are compared with experiments and/or the other numerical results to validate the present numerical method.

Effective numerical approach to assess low-cycle fatigue behavior of pipe elbows

  • Jang, Heung Woon;Hahm, Daegi;Jung, Jae-Wook;Hong, Jung-Wuk
    • Nuclear Engineering and Technology
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    • v.50 no.5
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    • pp.758-766
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    • 2018
  • We developed numerical models to efficiently simulate the low-cycle fatigue behavior of a pipe elbow. To verify the model, in-plane cyclic bending tests of pipe elbow specimens were conducted, and a through crack occurred in the vicinity of the crown. Numerical models based on the erosion method and tie-break method are developed, and the numerical results are compared with experimental results. The calculated results of both models are in good agreement with experimental results, and the model using the tie-break method possesses two times faster calculation speed. Therefore, the numerical model based on the tie-break method would be beneficial to evaluate the strength of piping systems under seismic loadings.

A MATRIX FORMULATION OF THE TAU METHOD FOR FREDHOLM AND VOLTERRA LINEAR INTEGRO-DIFFERENTIAL EQUATIONS

  • Aliabadi, M.-Hosseini;Shahmorad, S.
    • Journal of applied mathematics & informatics
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    • v.9 no.2
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    • pp.667-677
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    • 2002
  • In this paper we obtain the matrix Tau Method representation of a general boundary value problem for Fredholm and Volterra integro-differential equations of order $\nu$. Some theoretical results are given that simplify the application of the Tau Method. The application of the Tau Method to the numerical solution of such problems is shown. Numerical results and details of the algorithm confirm the high accuracy and user-friendly structure of this numerical approach.

Application of Preconditioning Method to Cavitating Flow Computation

  • Shin, Byeong-Rog
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1903-1908
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    • 2004
  • A preconditioned numerical method for gas-liquid two-phase flows is applied to solve cavitating flow. The present method employs a finite-difference dual time-stepping integration procedure and the MUSCLTVD scheme. A homogeneous equilibrium cavitation model is used. The present density-based numerical method permits simple treatment of the whole gas-liquid two-phase flow field, including wave propagation, large density changes and incompressible flow characteristics at low Mach number. Some internal flows such as convergent-divergent nozzles are computed using this method. Comparisons of predicted and experimental results are provided and discussed.

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NUMERICAL SOLUTION OF ABEL'S GENERAL FUZZY LINEAR INTEGRAL EQUATIONS BY FRACTIONAL CALCULUS METHOD

  • Kumar, Himanshu
    • Korean Journal of Mathematics
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    • v.29 no.3
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    • pp.527-545
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    • 2021
  • The aim of this article is to give a numerical method for solving Abel's general fuzzy linear integral equations with arbitrary kernel. The method is based on approximations of fractional integrals and Caputo derivatives. The convergence analysis for the proposed method is also given and the applicability of the proposed method is illustrated by solving some numerical examples. The results show the utility and the greater potential of the fractional calculus method to solve fuzzy integral equations.

The change of critical current with crack formation in a Bi-2223/Ag tape (크랙에 의한 Bi-2223/Ag 테이프의 임계전류 변화)

  • 박을주;설승윤
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.249-252
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    • 2002
  • The change of critical current with a crack formation in a Bi-2223/Ag tape was studied by experimental and numerical analyses. Critical current of Bi-2223/Ag tape was measured with a continuous DC-power supply. The current-voltage relation of a Bi-2223/Ag tape is measured by the four point method. Numerical method is used to solve two dimensional heat conduction equation. By comparing the experimental and numerical results, the validity of numerical method is verified.

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Solids 3-D with bounded tensile strength under the action of thermal strains. Theoretical aspects and numerical procedures

  • Pimpinelli, Giovanni
    • Structural Engineering and Mechanics
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    • v.18 no.1
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    • pp.59-78
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    • 2004
  • This paper is devoted to illustrate some numerical procedures to solve the boundary equilibrium problems of three-dimensional solids that are subjected to thermal strains. The constitutive equations take into account the bounded tensile strength of the material and they are presented in the framework of non-linear elasticity and small strains. The associated equilibrium problem is solved numerically by means of the finite element method and the numerical techniques, i.e. the Newton-Raphson method and the secant method, are revised in order to assure the solution convergence of the discretized problem. Some numerical examples are illustrated.

Numerical solution of linear elasticity by preconditioning cubic spline collocation

  • Lee, Yong-Hun
    • Communications of the Korean Mathematical Society
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    • v.11 no.3
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    • pp.867-880
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    • 1996
  • Numerical approximations to the linear elasticity are traditionally based on the finite element method. In this paper we propose a new formulation based on the cubic spline collocation method for linear elastic problem on the unit square. We present several numerical results for the eigenvalues of the matrix represented by cubic collocation method and preconditioner matrix which is preconditioned by FEM and FDM. Finally we present the numerical solution for some example equation.

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Numerical Analysis of a Round Disk Capacitor Using Annular Patch Subdomains (환형띠 조각면을 이용한 원형 축전기의 수치해석)

  • 구본희;김채영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.6
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    • pp.843-850
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    • 1990
  • A numerical method is presented for determining the static charge distribution and the capacitance of a round disk capacitor. In the employed numerical scheme annular patch subdomains are introduced to reduce the matrix size and to mprove the accuracy of the numerical calculations. The method of moments is utilized to calculate the charge distribution, and the capacitance and equipotential lines are also found from the numerically computed charge distributions. To show the validity of the results the proposed method is applied to the round disk and the dielectric filled capacitor.

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A Study on Numerical Calculation of Gas Migration from the Sanitary Landfill (쓰레기 매립지에서 가스유출 계산에 관한 연구)

  • 이해승
    • Journal of environmental and Sanitary engineering
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    • v.13 no.3
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    • pp.43-51
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    • 1998
  • This study presents a numerical method for calculating gas flow around a sanitary landfill gas vent, when gas flows by pressure. The method described is a three-dimensional compartmental model and includes methods to determine the dimensions for the model. Using the numerical method, controll of press and gases flowing out to the air through final cover soil, and degine of sanitary landfill gas vents.

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