Sökning: "waveguide finite element"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden waveguide finite element.

  1. 1. Waveguide Finite Elements Applied on a Car Tyre

    Författare :Carl-Magnus Nilsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave equation; wave solution; waveguide; finite element; spectral finite element; tyre noise; tyre vibration; input power; shells; pre stress; fluid shell coupling; axi--symmetric;

    Sammanfattning : Structures acting as waveguides are quite common withexamples being, construction beams, fluid filled pipes, railsand extruded aluminium profiles. Curved structures like cartyres and pipe-bends may also be considered as waveguides. Wavesolutions in such structures may be found by a method calledthe Waveguide Finite Element Method or WFEM. LÄS MER

  3. 2. Numerical methods for waveguide modelling

    Författare :Christer Johansson; Björn Engquist; Per Lötstedt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Waveguide; finite element; hp-adaptivity; helmholtz; maxwell; Numerical analysis; Numerisk analys;

    Sammanfattning : Waveguides are used to transmit electromagnetic signals. Their geometry is typically long and slender. This particular shape can be used in the design of efficient computational methods. Only special modes are transmitted and eigenvalue and eigenvector analysis becomes important. LÄS MER

  4. 3. Direct and Inverse Methods for Waveguides and Scattering Problems in the Time Domain

    Författare :Erik Abenius; Per Lötstedt; Mats Gustafsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; FDTD; finite-element; hybrid; thin sheet; waveguide; PML; inverse scattering; adjoint; gradient-based; minimization; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Numerical simulation is an important tool in understanding the electromagnetic field and how it interacts with the environment. Different topics for time-domain finite-difference (FDTD) and finite-element (FETD) methods for Maxwell's equations are treated in this thesis. LÄS MER

  5. 4. Modern numerical methods in electromagnetics applied to the design of reflector antennas and horn feeds

    Författare :Martin Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reflector antenna; cluster feed; offset; dual-reflector feed; mode matching; very long baseline interferometry; circular waveguide; diffraction; physical optics; corrugated horn; coaxial waveguide; VLBI; dual-frequency; low noise; finite element method; ray tracing; dual-band;

    Sammanfattning : .... LÄS MER

  7. 5. Effective vibro-acoustical modelling of rubber isolators

    Författare :Michael Coja; Leif Kari; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; Rubber isolator; Bush mounting; Dynamic stiffness; Waveguide; Fractional derivatives; Mode-matching; Pre-compressed; Prestrain; Preload; Predeformation; Viscoelasticity; Dispersion; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : This thesis, gathering four papers, concerns the enhancement in understanding and modelling of the audible dynamic stiffness of vibration rubber isolators including experimental measurements. Paper A studies the performances of three different types of vibration isolator using an indirect measurement technique to estimate the blocked dynamic transfer stiffness of each specimen. LÄS MER