• Title/Summary/Keyword: Runge-Kutta

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Analysis of Capsizing Phenomena of a Shop in Waves (파도중 선박의 전복 현상 해석)

  • 안창구;고창두
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.1 no.1
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    • pp.27-38
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    • 1995
  • In this paper, a program for the calculation of GZ curve for a ship in waves is developed and GZ curves for a ferry in the still water and in waves are calculated. And the added mass, damping, restoring forces and wave exciting forces are calculated by using the strip theory given by Salvesen, Tuck, Faltinsen. Capsizing simulations are perfoned in consideration if the nonlinear restoring forces of the ship in waves by using the Runge-Kutta 4-th method.

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CENTRAL SCHEMES WITH LAX-WENDROFF TYPE TIME DISCRETIZATIONS

  • Shin, Su-Yeon;Hwang, Woon-Jae
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.4
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    • pp.873-896
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    • 2011
  • The semi-discrete central scheme and central upwind scheme use Runge-Kutta (RK) time discretization. We do the Lax-Wendroff (LW) type time discretization for both schemes. We perform numerical experiments for various problems including two dimensional Riemann problems for Burgers' equation and Euler equations. The results show that the LW time discretization is more efficient in CPU time than the RK time discretization while maintaining the same order of accuracy.

Detachment of Vane Tip in a Positive Displacement Vane Pump (베인 이간 현상에 관한 연구)

  • 문호지;조명래;한동철
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.04a
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    • pp.204-209
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    • 1997
  • This paper reports on the theoretical study of the vane motions in a positive displacement vane pump. Vane detachment cause the pressure fluctuation, noise, wear in cam ring, and decrease the volumetric efficiency. Dynamic equation of vane motion and flow continuity equation have been modeled and solved simultaneously using 4th order Runge-Kutta method. As results of analysis, vane detachment occurs due to pressure overshoot by excess compression in the pumping chamber. Amount of vane detachment has been reduced by decreasing the pressure overshoot.

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Motions of Asymmetric Particles in A Periodic Cellular Flowfield (주기적인 Cellular 유동장내에 놓여진 비대칭형 입자의 운동에 관한 연구)

  • 김윤제
    • The Korean Journal of Rheology
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    • v.8 no.2
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    • pp.139-146
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    • 1996
  • 2차원 비점성 Euler 방정식의 Stuart 해에 의하여 주어지는 주기적인 유동장, 소위 말하여 Stuart와동장내에 놓여있는 아주 작은 비대칭성 입자의 다양한 부력 변수에 따른 침 강운동을 고찰하엿다. 본 연구에서 사용한 수치방법은 매질의 준전적인 Stokes 방정식과 입 자의 평형방정식을 연계하였다. 다양한 초기 배향각 또는 형상비에 따른 궤적이나 각변화를 예측하기 위하여 힘과 토오크 관계식을 입자의 운동방정식에 적용하였으며 4차 Runge-Kutta 방정식을 이용하여 입자의 운동을 규명하였다.

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Incompressible Viscous Analysis on Unstructured Meshes using Artificial Compressibility Method (가압축성 기법을 이용한 비정렬 격자상에서의 비압축성 점성해석)

  • Moon Young J.
    • 한국전산유체공학회:학술대회논문집
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    • 1995.10a
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    • pp.113-117
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    • 1995
  • Viscous analysis on incompressible flows is performed using unstructured triangular meshes. A two-dimensional and axisymmetric incompressible Navier-Stokes equations are solved in time-marching form by artificial compressibility method. The governing equations are discretized by a cell-centered based finite-volume method. and a centered scheme is used for inviscid and viscous fluxes with fourth order artificial dissipation. An explicit multi-stage Runge-Kutta method is used for the time integration with local time stepping and implicit residual smoothing. Convergence properties are examined and solution accuracies are also validated with benchmark solution and experiment.

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NUMERICAL INVESTIGATION OF INTERACTION BEHAVIOR BETWEEN CAVITATION BUBBLE AND SHOCK WAVE

  • Shin, Byeong-Rog;An, Young-Joon
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03a
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    • pp.215-220
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    • 2008
  • A numerical method for gas-liquid two-phase flow is applied to solve shock-bubble interaction problems. The present method employs a finite-difference Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. By this method, a Riemann problem for shock tube was computed for validation. Then, shock-bubble interaction problems between cylindrical bubbles located in the liquid and incident liquid shock wave are computed.

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NUMERICAL INVESTIGATION OF INTERACTION BEHAVIOR BETWEEN CAVITATION BUBBLE AND SHOCK WAVE

  • Shin, Byeong-Rog;An, Young-Joon
    • 한국전산유체공학회:학술대회논문집
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    • 2008.10a
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    • pp.215-220
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    • 2008
  • A numerical method for gas-liquid two-phase flow is applied to solve shock-bubble interaction problems. The present method employs a finite-difference Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. By this method, a Riemann problem for shock tube was computed for validation. Then, shock-bubble interaction problems between cylindrical bubbles located in the liquid and incident liquid shock wave are computed.

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Dynamic bucking of orthotropic cylindrical shells (직교이방성 원통쉘의 동적좌굴)

  • Lu, Sung Y.;Kim, Chon w
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.4
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    • pp.266-273
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    • 1981
  • 갑자기 작용하는 외압을 받는 직교이방성원통쉘의 동적좌굴을 해석하였다. Donnell-Karnam 형의 비선형방정식을 유도하였으며 쉘의 초기불완전성도 고려하였다. Galerkin의 방법을 사용하여 운동방정식을 구하고 Runge-Kutta 수직해법으로 비선형방정식을 풀었다. 쉘의 직교이방성특성이 처짐-하중 관계식의 비선형성에 미치는 영향을 검토하였으며 동적산출하중의 판별법을 정의하였다. 본 연구의 결과, 직교이방성원통쉘은 쉘의 초기불완전성에 그리 민감하지 않음을 보여주었다.

Nonlinear vibration of oscillatory systems using semi-analytical approach

  • Bayat, Mahmoud;Bayat, Mahdi;Pakar, Iman
    • Structural Engineering and Mechanics
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    • v.65 no.4
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    • pp.409-413
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    • 2018
  • In this paper, He's Variational Approach (VA) is used to solve high nonlinear vibration equations. The proposed approach leads us to high accurate solution compared with other numerical methods. It has been established that this method works very well for whole range of initial amplitudes. The method is sufficient for both linear and nonlinear engineering problems. The accuracy of this method is shown graphically and the results tabulated and results compared with numerical solutions.

HOPF BIFURCATION IN NUMERICAL APPROXIMATION FOR DELAY DIFFERENTIAL EQUATIONS

  • Zhang, Chunrui;Liu, Mingzhu;Zheng, Baodong
    • Journal of applied mathematics & informatics
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    • v.14 no.1_2
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    • pp.319-328
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    • 2004
  • In this paper we investigate the qualitative behaviour of numerical approximation to a class delay differential equation. We consider the numerical solution of the delay differential equations undergoing a Hopf bifurcation. We prove the numerical approximation of delay differential equation had a Hopf bifurcation point if the true solution does.