• Title/Summary/Keyword: analytical solutions

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A photo-thermal interaction in semi-conductor medium with cylindrical cavity by analytical and numerical methods

  • Abbas, Ibrahim A.
    • Geomechanics and Engineering
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    • v.25 no.4
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    • pp.267-273
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    • 2021
  • In this work, we compare the analytical solutions with the numerical solutions for photothermal interactions in semiconductor medium containing cylindrical cavity. This paper is devoted to a study of the photothermal interactions in semiconductor medium in the context of the coupled photo-thermal model. The basic equations are formulated in the domain of Laplace transform and the eigenvalue scheme are used to get the analytical solutions. The numerical solution is obtained by using the implicit finite difference method (IFDM). A comparison between the analytical solution and the numerical solutions are obtained. It is found that the implicit finite difference method (IFDM) is applicable, simple and efficient for such problems.

A Theoretical Study on the Analytical Solutions for Laterally Loaded Pile (횡방향 하중을 받는 말뚝의 해석해에 대한 이론적 고찰)

  • Lee, Seung-Hyun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.111-116
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    • 2011
  • Analytical solutions for laterally loaded piles were derived. Critical pile length which can be considered as the length for behaving as long pile was investigated varying with densities of sandy soils. Lateral behaviors obtained from analytical solution and numerical solution were also investigated. Non-dimensional critical pile lengths obtained from analytical solutions for three types of pile head boundary conditions were 2.3~3.2. By comparing analytical solutions with numerical solutions, distribution of pile deflection and that of moment were similar and it can be seen that pile head deflection obtained by analytical method is conservative. And the values of moments were not too different between analytical solution and numerical solution.

Nonlinear vibration analysis of a type of tapered cantilever beams by using an analytical approximate method

  • Sun, Weipeng;Sun, Youhong;Yu, Yongping;Zheng, Shaopeng
    • Structural Engineering and Mechanics
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    • v.59 no.1
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    • pp.1-14
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    • 2016
  • In this paper, an alternative analytical method is presented to evaluate the nonlinear vibration behavior of single and double tapered cantilever beams. The admissible lateral displacement function satisfying the geometric boundary conditions of a single or double tapered cantilever beam is derived by using Rayleigh-Ritz method. Based on the Lagrange method and the Newton Harmonic Balance (NHB) method, analytical approximate solutions in closed and explicit form are obtained. These approximate solutions show excellent agreement with those of numeric method for small as well as large amplitude. Moreover, due to brevity of expressions, the present analytical approximate solutions are convenient to investigate effects of various parameters on the large amplitude vibration response of tapered beams.

Quasi-3D analysis of Axial Flux Permanent Magnet Rotating Machines using Space Harmonic Methods (공간고조파법을 이용한 축 자속 영구자석 회전기기의 준(準)-3D 특성 해석)

  • Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.942-948
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    • 2011
  • This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

CONFORMABLE FRACTIONAL SENSE OF FOAM DRAINAGE EQUATION AND CONSTRUCTION OF ITS SOLUTIONS

  • DARVISHI, MOHAMMAD T.;NAJAFI, MOHAMMAD;SHIN, BYEONG-CHUN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.25 no.3
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    • pp.132-148
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    • 2021
  • The modified F-expansion method is used to construct analytical solutions of the foam drainage equation with time- and space-fractional derivatives. The conformable derivatives are considered as spacial and temporal ones. As a result, some analytical exact solutions including kink, bright-dark soliton, periodic and rational solutions are obtained.

New analytical solutions to water wave diffraction by vertical truncated cylinders

  • Li, Ai-jun;Liu, Yong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.2
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    • pp.952-969
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    • 2019
  • This study develops new analytical solutions to water wave diffraction by vertical truncated cylinders in the context of linear potential theory. Three typical truncated surface-piercing cylinders, a submerged bottom-standing cylinder and a submerged floating cylinder are examined. The analytical solutions utilize the multi-term Galerkin method, which is able to model the cube-root singularity of fluid velocity near the edges of the truncated cylinders by expanding the fluid velocity into a set of basis function involving the Gegenbauer polynomials. The convergence of the present analytical solution is rapid, and a few truncated numbers in the series of the basis function can yield results of six-figure accuracy for wave forces and moments. The present solutions are in good agreement with those by a higher-order BEM (boundary element method) model. Comparisons between present results and experimental results in literature and results by Froude-Krylov theory are conducted. The variation of wave forces and moments with different parameters are presented. This study not only gives a new analytical approach to wave diffraction by truncated cylinders but also provides a reliable benchmark for numerical investigations of wave diffraction by structures.

Analytical Prediction for the Cogging Torque of the Permanent Magnet Machines With Multi-Pole Rotor (다극회전자를 갖는 영구자석기기의 코깅토크에 대한 해석적 예측)

  • Jang, Seok-Myeong;Choi, Jang-Young;Ko, Kyoung-Jin;Park, Ji-Hoon
    • Proceedings of the KIEE Conference
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    • 2007.04c
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    • pp.56-58
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    • 2007
  • This paper deals with analytical prediction for the cogging torque of permanent magnet machines with multi-pole rotor First. open-circuit field solutions are derived using a magnetic vector potential and a two-dimensional (2-d) polar coordinate systems. On the basis of derived open-circuit field solutions and 2-d permeance functions. we also derive the analytical solutions for the open-circuit field considering stator slotting effects and cogging torque. All analytical results are shown in goof agreement with those obtained from finite element (FE) analyses.

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Analytical solutions for skewed thick plates subjected to transverse loading

  • Chun, Pang-Jo;Fu, Gongkang;Lim, Yun Mook
    • Structural Engineering and Mechanics
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    • v.38 no.5
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    • pp.549-571
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    • 2011
  • This paper presents analytical solutions for skewed thick plates under transverse loading that have previously been unreported in the literature. The thick plate solution is obtained in a framework of an oblique coordinate system. The governing equation is first derived in the oblique coordinate system, and the solution is obtained using deflection and rotation as partial derivatives of a potential function developed in this research. The solution technique is applied to three illustrative application examples, and the results are compared with numerical solutions in the literature and those derived from the commercial finite element analysis package ANSYS 11. These results are in excellent agreement. The present solution may also be used to model skewed structures such as skewed bridges, to facilitate efficient routine design or evaluation analyses, and to form special elements for finite element analysis. At the same time, the analytical solution developed in this research could be used to develop methods to address post-buckling and dynamic problems.

Improved Analytical Modeling of a Ellipse Shape Permanent Magnet Rotor in Ultra-High-Speed Brushless DC motor for the Reduction of Torque Ripple

  • Sung, So-Young;Jeong, Jae-Hoon;Choi, Ji-Hwan;Park, Hyung-Il;Jang, Seok-Myeong
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.945-950
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    • 2013
  • This paper deals with the ellipse permanent magnet machines for the minimization of torque ripple based on electromagnetic field theory. On the basis of a magnetic vector potential and a two dimensional (2-D) polar system, analytical solutions for flux density due to permanent magnet (PM) and current are obtained. In particular, the analytical solutions for mathematical expressions of magnets with different circumferential thicknesses can be solved introducing improved magnetization modeling techniques. The analytical results are validated extensively be nonlinear finite element solutions, a reduction of torque ripple can be achieved.

Analytical solutions for buckling of simply supported rectangular plates due to non-linearly distributed in-plane bending stresses

  • Jana, Prasun;Bhaskar, K.
    • Structural Engineering and Mechanics
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    • v.26 no.2
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    • pp.151-162
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    • 2007
  • Rigorous analytical solutions are obtained for the plane stress problem of a rectangular plate subjected to non-linearly distributed bending loads on two opposite edges. They are then used in a Galerkin type solution to obtain the corresponding convergent buckling loads. It is shown that the critical bending moment depends significantly on the actual edge load distribution and further the number of nodal lines of the buckled configuration can also be different from that corresponding to a linear antisymmetric distribution of the bending stresses. Results are tabulated for future use while judging approximate numerical solutions.