Sökning: "electromagnetics"

Visar resultat 1 - 5 av 44 avhandlingar innehållade ordet electromagnetics.

  1. 1. Computational electromagnetics : software development and high frequency modeling of surface currents on perfect conductors

    Författare :Sandy Sefi; Jesper Oppelstrup; Francisco Saez de Adana; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High frequency approximations; Maxwell’s equations; Method of Moments; Physical Optics; Geometrical Theory of Diffraction; Extraction Extrapolation; Numerical analysis; Numerisk analys;

    Sammanfattning : In high frequency computational electromagnetics, rigorous numerical methods be come unrealistic tools due to computational demand increasing with the frequency. Instead approximations to the solutions of the Maxwell equations can be employed to evaluate th electromagnetic fields. LÄS MER

  3. 2. Hybrid methods for computational electromagnetics in the frequency domain

    Författare :Stefan Hagdahl; KTH; []
    Nyckelord :Computational Electromagnetics; Hybrid Methods; Boundary Element Method; Geometrical Theory of Diffraction;

    Sammanfattning : In this thesis we study hybrid numerical methods to be usedin computational electromagnetics. We restrict the methods tospectral domain and scattering problems. The hybrids consist ofcombinations of Boundary Element Methods and Geometrical Theoryof Diffraction.In the thesis three hybrid methods will be presented. LÄS MER

  4. 3. Material distribution-based topology optimization for wave propagation problems

    Författare :Ahmad Hasnain Bokhari; Eddie Wadbro; Martin Berggren; Roland Herzog; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; topology optimization; material distribution; wave propagation problems; Helmholtz equation; acoustics; electromagnetics; plasmonics;

    Sammanfattning : This thesis employs material distribution-based topology optimization for wave propagation problems. In the material distribution approach, we define a material indicator function that models the presence and absence of material in a design domain. LÄS MER

  5. 4. Weld Pool Simulations

    Författare :Marcus Edstorp; Högskolan Väst; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Arc Welding; Weld Pool; Multiphysics Simulations; Moving Boundaries; Free Surfaces; Mesh Motion; Two-Phase Flow; Incompressible Flow; Electromagnetics; Finite Element Methods; Applied mathematics; Tillämpad matematik; Manufacturing engineering; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik; Arc Welding; Weld Pool; Multiphysics Simulations; Moving Boundaries; Free Surfaces; Mesh Motion; Two-Phase Flow; Incompressible Flow; Electromagnetics; Finite Element Methods;

    Sammanfattning : This investigation is devoted to the study of welding and its effect on the workpiece, focusing on the thermo and fluid dynamical phenomena occuring during a autogenous or nonautogenous arc fusion welding process. Its aim is to simulate the behaviour of the weld pool and analyze the consequence of the solid-liquid phase change, thus obtaining a methodology for predicting the appearance of weld defects related to solidification and cooling. LÄS MER

  7. 5. Adaptive methods in computational electromagnetics

    Författare :Pär Ingelström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite elements; hybris methods; finite-difference time-domain; error estimation; mesh refinement; Padé approximation;

    Sammanfattning : .... LÄS MER