• 제목/요약/키워드: Numerical Computation

검색결과 1,367건 처리시간 0.03초

단이 진 2차원 벽면분류에 대한 수치 해석 (Numerical study on the two-dimensional stepped wall jet)

  • 윤순현;엄윤섭;정명균
    • 대한기계학회논문집
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    • 제12권4호
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    • pp.865-875
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    • 1988
  • 본 연구에서는 부정숙 등에 의한 실험결과를 토대로 하여, 단이 진 2차원 벽 면분류에 대한 수치해석으로 표준 K-.epsilon.모델과 LRM 그리고 PAM을 적용하고, upwind 및 skew-upwind scheme을 적용하여 그 결과를 검토하고자 한다.

Numerical Computations of Extreme Wave Load on a Cylinder Using Frequency-Focusing unidirectional waves

  • 경조현
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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    • pp.135-140
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    • 2006
  • Numerical computations are made to predict wave loads on a vertical cylinder in an extreme wave. To generate the extreme wave, a frequency-focused unidirectional wave is adopted in three-dimensional numerical wave tank. The mathematical formulation is wide in the scope of the potential theory with fully nonlinear free surface conditions. As a numerical method, finite element method based on variational principle is applied. Comparisons between the present numerical results and the previous computation data. show a good agreement.

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On the numerical computation of the matrix exponential

  • Yu, Dong-Won
    • 대한수학회지
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    • 제31권4호
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    • pp.633-643
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    • 1994
  • Let us consider the initial-value problem of dimension m: $$ \frac{d\tau}{d}y(\tau) = f(\tau, Y(\tau)), y(0) = y_0, \tau \geq 0, (1.1) $$ Where $ = (f_1, f_2, \cdots, f_m) and y = (y_1, y_2, \cdots, y_m)$.

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임피던스 경계 조건, 모멘트 법과 몬테 카를로 방법을 이용한 논의 산란계수 수치적 계산과 측정 데이터와의 비교 (Numerical Computation of the Backscattering Coefficients of Rice Fields Using the Impedance Boundary Condition, Moment Method and Monte Carlo Method)

  • 홍진영;오이석
    • 한국전자파학회논문지
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    • 제18권7호
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    • pp.819-827
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    • 2007
  • 본 논문은 논에 대한 전파 산란 특성을 측정하고, 수치적 계산 결과와 비교함으로써 벼의 수치적 모델링에 대한 전파 산란 알고리즘을 제시하고자 한다. 임피던스 경계 조건과 dyadic 그린함수로부터 임피던스 표면 위(수면)의 손실 있는 유전체(벼)에 대한 적분 방정식을 유도하였고, 모멘트 법을 이용하여 유전체의 체적 전류를 계산하였다. 또한, 몬테 카를로 방법을 적용하여 입사 각도 및 편파에 따른 후방 산란 계수를 수치적으로 계산하였다. 1.85 GHz의 측정 시스템을 이용하여 논의 후방 산란 계수를 측정하였으며, 본 논문에서 제시한 알고리즘의 계산 결과와 비교, 검증하였다.

A semi-analytical and numerical approach for solving 3D nonlinear cylindrical shell systems

  • Liming Dai;Kamran Foroutan
    • Structural Engineering and Mechanics
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    • 제87권5호
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    • pp.461-473
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    • 2023
  • This study aims to solve for nonlinear cylindrical shell systems with a semi-analytical and numerical approach implementing the P-T method. The procedures and conditions for such a study are presented in practically solving and analyzing the cylindrical shell systems. An analytical model for a nonlinear thick cylindrical shell (TCS) is established on the basis of the stress function and Reddy's higher-order shear deformation theory (HSDT). According to Reddy's HSDT, Hooke's law in three dimensions, and the von-Kármán equation, the stress-strain relations are developed for the thick cylindrical shell systems, and the three coupled nonlinear governing equations are thus established and discretized as per the Galerkin method, for implementing the P-T method. The solution generated with the approach is continuous everywhere in the entire time domain considered. The approach proposed can also be used to numerically solve and analyze the nonlinear shell systems. The procedures and recurrence relations for numerical solutions of shell systems are presented. To demonstrate the application of the approach in numerically solving for nonlinear cylindrical shell systems, a specific nonlinear cylindrical shell system subjected to an external excitation is solved numerically. In numerically solving for the system, the present approach shows higher efficiency, accuracy, and reliability in comparison with that of the Runge-Kutta method. The approach with the P-T method presented is practically sound especially when continuous and high-quality numerical solutions for the shell systems are considered.