• Title/Summary/Keyword: 갈라킨 법

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Numerical prediction of shell-side flow with inclined baffles (경사진 배플이 있는 셀측의 수치적 해석)

  • 김은필
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.5
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    • pp.119-124
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    • 2000
  • A finite element method is applied to investigate the characteristics of the fluid flow and heat transfer performance in a channel in terms of the various effects of baffle cuts, baffle angles, and leakages. The results show that the decrease of a baffle cut gives a good heat transfer enhancement. However, it also increases pressure drop. In the case of an inclined baffle, the result shows that the pressure drop decreases with a reasonable heat transfer performance. But a steeply inclined baffle gives adverse effects on the performance of the channel. The clearances between baffle-to-shell and tube-to-baffle affect the overall performance. The effects of these parameters are discussed in details.

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Block and Extraction of Wave Energy Using a Rolling Porous Pendulum Plate (횡 방향으로 운동하는 투과성 진자판을 이용한 파랑에너지 차단과 추출)

  • Cho, Il-Hyoung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.4
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    • pp.180-190
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    • 2018
  • The preliminary study was carried out to utilize the rolling porous pendulum plate as a hybrid system combining blocking and extracting of wave energy. The Galerkin method suggested by Porter and Evans (1995) was used to solve the diffraction and radiation problems to obtain reflection and transmission coefficient, roll displacement, extracted power. The Galerkin method provides better convergence than the matched eigenfunction expansion method (MEEM), which improves the accuracy of the analytical solution even if the CPU time is shorter. The porous plate can not be said to be more effective than the impermeable plate in terms of wave energy extraction and wave blocking, but it has the advantage of reducing the wave load and exchanging seawater.

Study of a Mixed Finite Element Model for the Analysis of a Geometrically Nonlinear Plate (기하학적 비선형 판재 해석을 위한 혼합형 FE Model 연구)

  • Kim, Woo-Ram;Choi, Youn-Dae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.10
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    • pp.1427-1435
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    • 2010
  • A mixed finite element model was developed using the classical plate theory to analyze the nonlinear bending of a plate. The appropriate weight functions for the constraints integrated over the domain were determined by the Lagrange multiplier method by using the principle of minimum virtual energy; which provides the constitutive relations between force-like variables and strains. All of detail terms of element wise coefficient matrices and associate tangent matrices to be used in the Newton iterative method are presented. Then, the linear solutions of the current model and those of the traditional displacement model under the SS (simple support) boundary conditions were compared with the existing analytical solution. The post-processed images of the nonlinear results of the force-like variables are presented to show the continuity of the solutions at the joint of the element boundaries. Finally, the converged nonlinear finite element solutions of the current model are compared with those of existing traditional displacement model.