Sökning: "cylindrical coordinates"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden cylindrical coordinates.

  1. 1. Cylindrical Waveguide Slot Antenna Analysis

    Författare :Johan Wettergren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; basis function; mutual admittance; cylinder; MPIE; slot; integral equation; waveguide; antenna; mutual coupling; moment method; EFIE;

    Sammanfattning : Waveguide slot antennas with longitudinal and transverse slots are analyzed using a rigorous method. The antennas are divided into regions, which are analyzed separately and matched by a moment method procedure. At the apertures between the regions, the electric fields are expanded in trigonometric basis functions. LÄS MER

  3. 2. Wave Splitting and Effective Boundary Conditions for Structural Elements

    Författare :Martin Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; approximate boundary condition; Mindlin plate; Timoshenko beam; thin plates; cylindrical coordinates; series approximation; wave splitting; dispersion; fluid-loaded plate; Biot;

    Sammanfattning : The subject of this thesis is twofold. The first part concerns the wave splitting of structural elements. The second part concerns approximate boundary conditions for fluid-loaded thin plates. Wave splitting is a mathematical tool for the formulation of scattering problems in the time domain that aims at solving inverse problems, e. LÄS MER

  4. 3. Moment Method Analysis of Antennas in Reverberation Chambers and Cylindrical Structures

    Författare :Ulf Carlberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cavity; spectral domain method; cylindrical structure; Ewald summation; Green s function; absorption cross section; moment method; reverberation chamber; antenna;

    Sammanfattning : This thesis is a collection of papers using the method of moments for numerical analysis. The papers can be divided into two main groups; a study of antennas in reverberationchambers, and a study of antennas in cylindrical structures.The reverberation chamber is a metal cavity for measuring antennas and other devices. LÄS MER

  5. 4. Moment Method Analysis of Antennas in Reverberation Chambers and Cylindrical Structures

    Författare :Ulf Carlberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna; spectral domain method; reverberation chamber; Ewald summation; moment method; cavity; cylindrical structure; Green s function; absorption cross section;

    Sammanfattning : This thesis is a collection of papers using the method of moments for numerical analysis. The papers can be divided into two main groups; a study of antennas in reverberation chambers and a study of antennas in cylindrical structures.The reverberation chamber is a metal cavity for measuring antennas and other devices. LÄS MER

  7. 5. Modelling crack-induced ultrasonic scattering in a thick-walled pipe

    Författare :Jacob Rubenson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cylindrical pipes; Non-Destructive Testing; Crack; Ultrasonic waves; Hypersingular integral method;

    Sammanfattning : Ultrasonic testing is used in several industries where there are high demands on safety, e.g. nuclear power and aerospace industries. In the nuclear industry and elsewhere there are many pipes that need to be tested. LÄS MER