• Title/Summary/Keyword: BiCGstab(l)

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Computational Complexity of BiCGstab(l) in Multi-Level Fast Multipole Method(MLFMM) and Efficient Choice of l (MLFMM(Multi-Level Fast Multipole Method) 방법에 적용된 BiCGstab(l)반복법의 l값에 따른 연산량 분석 및 효율적인 l값)

  • Lee, Hyunsoo;Rim, Jae-Won;Koh, Il-Suek;Seo, Seung-Mo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.3
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    • pp.167-170
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    • 2018
  • The method of moments(MoM) is one of the most popular integral-equation-based full-wave simulation methods, and the multi-level fast multipole method(MLFMM) algorithm can be used for its efficient calculation. When calculating the surface current on the large scatterer in the MoM or MLFMM, iterative methods for the final matrix inversion are used. Among them, BiCGstab(l) has been widely adopted due to its good convergence rate. The number of iterations can be reduced when l becomes larger, but the number of operations per iteration is increased. Herein, we analyze the computational complexity of BiCGstab(l) in the MLFMM method and propose an optimum choice of l.

Unstructured Finite-Volume Analysis of Vaporization Characteristics of Fuel Droplets in Laminar Flow Field (비정렬 유한체적법을 이용한 유동장 내의 연료액적 증발 특성 해석)

  • Kim, T.J.;Kim, Y.M.;Sohn, J.L.
    • Journal of ILASS-Korea
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    • v.5 no.1
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    • pp.13-22
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    • 2000
  • The present study has numerically analyzed the vaporization characteristics of fuel droplets in the high temperature convective flow field. The axisymmetric governing equations for mass, momentum, energy, and species are solved by an iterative and implicite unstructured finite-volume method. The moving boundary due to vaporization is handled by the deformable unstructured grid technique. The pressure-velocity coupling in the density-variable flows is treated by the SIMPLEC algorithm. In terms of the matrix solver, Bi-CGSTAB is employed for the numerically efficient and stable convergence. The n-decane is used as a liquid fuel and the initial droplet temperature is 300K. Computations are performed for the nonevaporating and evaporating droplets with the relative interphase velocity(25m/s). The unsteady vaporization process has been simulated up to the nondimensional time, 25. Numerical results indicate that the mathematical model developed in this study succesfully simulates the main features of the droplet vaporization process in the convective environment.

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