• Title/Summary/Keyword: Predictor-Corrector

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Development of Finite Element Method for the Extended Boussinesq Equations (확장형 Boussinesq 방정식의 유한요소모형 개발)

  • Woo, Seung-Buhm;Choi, Young-Kwang;Yoon, Byung-Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.3
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    • pp.133-141
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    • 2007
  • A finite element model is developed for the extended Boussinesq equations that is capable of simulating the dynamics of long and short waves. Galerkin weighted residual method and the introduction of auxiliary variables for 3rd spatial derivative terms in the governing equations are used for the model development. The Adams-Bashforth-Moulton Predictor Corrector scheme is used as a time integration scheme for the extended Boussinesq finite element model so that the truncation error would not produce any non-physical dispersion or dissipation. This developed model is applied to the problems of solitary wave propagation. Predicted results is compared to available analytical solutions and laboratory measurements. A good agreement is observed.

A spent nuclear fuel source term calculation code BESNA with a new modified predictor-corrector scheme

  • Duy Long Ta ;Ser Gi Hong ;Dae Sik Yook
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4722-4730
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    • 2022
  • This paper introduces a new point depletion-based source term calculation code named BESNA (Bateman Equation Solver for Nuclear Applications), which is aimed to estimate nuclide inventories and source terms from spent nuclear fuels. The BESNA code employs a new modified CE/CM (Constant Extrapolation - Constant Midpoint) predictor-corrector scheme in depletion calculations for improving computational efficiency. In this modified CE/CM scheme, the decay components leading to the large norm of the depletion matrix are excluded in the corrector, and hence the corrector calculation involves only the reaction components, which can be efficiently solved with the Talyor Expansion Method (TEM). The numerical test shows that the new scheme substantially reduces computing time without loss of accuracy in comparison with the conventional scheme using CRAM (Chebyshev Rational Approximation Method), especially when the substep calculations are applied. The depletion calculation and source term estimation capability of BESNA are verified and validated through several problems, where results from BESNA are compared with those calculated by other codes as well as measured data. The analysis results show the computational efficiency of the new modified scheme and the reliability of BESNA in both isotopic predictions and source term estimations.

The Efficient Algorithm for Simulating the Multiphase Flow

  • Yoon Seong Y;Yabe T.
    • Journal of computational fluids engineering
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    • v.9 no.1
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    • pp.18-24
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    • 2004
  • The unified simulation for the multiphase flow by predictor-corrector scheme based on CIP method is introduced. In this algorithm, the interface between different phases is identified by a density function and tracked by solving an advection equation. Solid body motion is modeled by the translation and angular motion. The mathematical formulation and numerical results are also described. To verify the efficiency, accuracy and capability of proposed algorithm, two dimensional incompressible cavity flow, the motion of a floating ball into water and a single rising bubble by buoyancy force are numerically simulated by the present scheme. As results, it is confirmed that the present scheme gives an efficient, stable and reasonable solution in the multiphase flow problem.

Local Response Recovery for Multilayered Composite Panels using Mesh Superposition (유한요소격자중첩을 이용한 복합재료평판의 변위 및 응력의 복원)

  • 박진우;김용협
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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    • pp.89-92
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    • 2000
  • In this paper, an effective procedure is presented for the local recovery of displacements and stresses in multilayered composite panels, which incorporate the local refinement using mesh superposition. The mesh superposition method is used to refine the global coarse mesh by superimposing refined mesh to the localized zone of interest without transition zones. The finite element model used is a solid element based on the Hellinger-Reissner variational principle. The a posteriori computation of the through-the-thickness distributions of displacements and stresses is achieved using a predictor-corrector procedure. The procedure utilizes the superconvergent stresses and nodal displacements of the finite element patch. The element patch is generated by locally superimposing a refined local mesh to the coarse global mesh.

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Analysis of the Flow in Square Cavity Using CIP Method in Non-staggered Grid Arrangement (비엇갈림 격자계에서 CIP법을 이용한 캐비티내의 유동해석)

  • Lee, Jung-Hee;Kang, Joon;Im, Do-Kiun;Kim, Charn-Jung
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1821-1826
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    • 2003
  • In this study, we discuss CIP method, which can treat compressible/incompressible problem and multi-phase problem. We can apply this method to the general equations by using CCUP. In this paper, non-staggered grid arrangement and predictor-corrector method are used to enhance later development and the solution accuracy and convergence performance. To validate the numerical algorithm proposed in this paper, the two-dimensional unsteady flow in the driven cavity is simulated. The numerical results of this subject using the present algorithm are compared with other numerical results. As a result, it is prived that the present scheme gives stable and improved solutions, and the results even coarse grid are in good agreement with other result using a fine grid arrangement.

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A Study on Multiphase Optimization of Machine Tool Structures (공작기계구조물의 다단계 최적화에 관한 연구)

  • 이영우;성활경
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.42-45
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    • 2002
  • In this paper, multiphase optimization of machine Tool structure is presented. The final goal is to obtain 1) light weight, 2) statically and dynamically rigid. and 3) thermally stable structure. The entire optimization process is carried out in three phases. In the first phase, multiple static optimization problem with two objective functions is treated using Pareto genetic algorithm. where two objective functions are weight of the structure and static compliance. In the second phase, maximum receptance is minimized using simple genetic algorithm. And the last phase, thermal deflection to moving heat sources is analyzed using Predictor-Corrector Method. The method is applied to a high speed line center design which takes the shape of back-column structure.

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CONCERNING THE RADIUS OF CONVERGENCE OF NEWTON'S METHOD AND APPLICATIONS

  • Argyros, Ioannis K.
    • Journal of applied mathematics & informatics
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    • v.6 no.3
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    • pp.685-696
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    • 1999
  • We present local and semilocal convergence results for New-ton's method in a Banach space setting. In particular using Lipschitz-type assumptions on the second Frechet-derivative we find results con-cerning the radius of convergence of Newton's method. Such results are useful in the context of predictor-corrector continuation procedures. Finally we provide numerical examples to show that our results can ap-ply where earlier ones using Lipschitz assumption on the first Frechet-derivative fail.

Application of TVD-McCormack Scheme to Analysis of Dam-Break Problems (댐붕괴 문제의 해석에 관한 TVD-McCormack기법의 적용)

  • Lee, Jong-Kyu;Kim, Tae-Kwan
    • Journal of Korea Water Resources Association
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    • v.36 no.3 s.134
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    • pp.365-374
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    • 2003
  • This is a study on application of a TVD-Mccormack scheme for the computation of one-dimensional dam-break flows. The TVD scheme not only has the ability to damp out oscillations, but also does not contain terms with adjustable parameters. Moreover, the TVD-McCormack scheme does not cause any additional difficulty when dealing with the source term of the equation and retains second-order accuracy in both space and time. In this study, by appropriately designing the limiter functions, the TVD property can be achieved, and numerical oscillations near a jump discontinuities can be eliminated or reduced. Also, this numerical scheme has less computational errors when the direction of the predictor-corrector step is in the same direction as the shock wane propagation.

Surf Zone Wave Transformations Simulated by a Fully Nonlinear Boussinesq Equation (완전비선형 Boussinesq방정식을 이용한 쇄파대의 파랑변형 모의)

  • 윤종태;김종무
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.4
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    • pp.296-308
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    • 2001
  • A fully nonlinear Boussinesq equation of Wei et al. is finite differenced by Adams predictor-corrector method. A spatially distributed source function and sponge layers are used to reduce the reflected waves in the domain and wale breaking mechanism is included in the equation. The generated waves are found to be good and the corresponding wale heights are very close to the target values. The shoaling of solitary wave and transformation of regular wave over submerged shelf were simulated successfully. The characteristics of breaking mechanism was identified through the numerical experiment and the results of two dimensional wave propagation test over the spherical shoal showed the importance of nonlinear wave model.

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