Search for dissertations about: "computational electromagnetic fields"

Showing result 1 - 5 of 24 swedish dissertations containing the words computational electromagnetic fields.

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

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

    Abstract : 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. READ MORE

  4. 2. Implementation of the spectral element method and iterative solution techniques for 3D controlled-source electromagnetic modelling

    Author : Michael Weiss; Thomas Kalscheuer; Michael Becken; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Controlled source electromagnetis; Electromagnetic theory; Numerical modelling; Applied geophysics; Geo-Electromagnetics; Spectral element method; Iterative solution methods; Preconditioning;

    Abstract : Controlled-source electromagnetic methods are imaging techniques applied at/on the surface of the Earth which record the electromagnetic field in order to assess the electrical conductivity distribution of the Earth’s subsurface, along with anomalies in this material property, as well as to characterise and interpret structures in Earth’s crust. Extracting information from the recorded electromagnetic data requires inverse modelling algorithms. READ MORE

  5. 3. Electromagnetic Interference in Distributed Outdoor Electrical Systems, with an Emphasis on Lightning Interaction with Electrified Railway Network

    Author : Nelson Theethayi; Rajeev Thottappillil; Farhad Rachidi; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Electromagnetic Compatibility EMC ; Lightning; Lightning Protection; Transmission Lines; Electromagnetic Wave Propagation; Underground Cables; Grounding; Electromagnetic Transients; Electromagnetic Interference; Shielding Effectiveness; Railway Systems; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : This thesis deals with the electromagnetic compatibility (EMC) problems of distributed electrical networks, especially that caused by lightning to electrified railway. Lightning transients were found to damage important devices that control train movements, causing traffic stoppage and delays. READ MORE

  6. 4. Boundary and Interface Conditions for Electromagnetic Wave Propagation using FDTD

    Author : Jon Häggblad; Björn Engquist; Olof Runborg; Thomas Rylander; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; Numerisk analys;

    Abstract : Simulating electromagnetic waves is of increasing importance, for example, due to the rapidly growing demand of wireless communication in the fields of antenna design, photonics and electromagnetic compatibility (EMC). Many numerical and asymptotic techniques have been developed and one of the most common is the Finite-Difference Time-Domain (FDTD) method, also known as the Yee scheme. READ MORE

  7. 5. Efficient Electromagnetic Induction Modelling : Adaptive mesh optimisation, advanced boundary methods and iterative solution techniques

    Author : Laura M. Buntin; Thomas Kalscheuer; Gunilla Kreiss; Zhengyong Ren; Klaus Spitzer; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Applied geophysics; Electromagnetic theory; Numerical Modelling; Geo-Electromagnetics; Magnetotellurics; Controlled-source electromagnetics; Goal-oriented adaptive mesh refinement; Perfectly-matched layers; Iterative solution methods; Preconditioning; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Abstract : Forward modelling of electromagnetic induction data simulates the electric and magnetic fields within a computational domain for a given distribution of electromagnetic material properties and a given source of the electromagnetic field. The quantities of interest are the fields at receiver locations at the Earth's surface. READ MORE