Sökning: "helmholtz ekvation"

Visar resultat 1 - 5 av 6 uppsatser innehållade orden helmholtz ekvation.

  1. 1. Moderling Acoustic Transmission in Towed Array Sonars : Computations of the coupled acoustic and elastic wave equations

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Bill Claesson; [2023]
    Nyckelord :;

    Sammanfattning : This thesis presents a method of solving the Helmholtz equation coupled with the Navier-Cauchy equation over a cross section of a Towed Array Sonar (TAS) modeled as a simplified cylindrical shell. The purpose of solving these equations is to estimate the transfer function of the pressure between the outside boundary and a position inside the TAS. LÄS MER

  3. 2. Computation of Underwater Acoustic Wave Propagation Using the WaveHoltz Iteration Method

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Paul Wall; [2022]
    Nyckelord :WaveHoltz iteration method; Helmholtz equation; Discontinuous Galerkin methods; Underwater acoustics.; WaveHoltziterativametod; Helmholtzekvation; DiskontinuerligaGalerkinmetoder; Undervattensakustik.;

    Sammanfattning : In this thesis, we explore a novel approach to solving the Helmholtz equation,the WaveHolz iteration method. This method aims to overcome some ofthe difficulties with solving the Helmholtz equation by providing a highlyparallelizable iterative method based on solving the time-dependent Waveequation. LÄS MER

  4. 3. Computation of Acoustic Wave Propagation Under Water

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Frida Thörn; [2022]
    Nyckelord :Wave equation; Helmholtz equation; Waveholtz iteration; finite difference method; summation by parts; energy method; point source; curvilinear coordinates; vågekvationen; helmholtz ekvation; waveholtz iteration; finita differens methoden; energimetoden; punktkälla; kurvlinjära koordinater; kroklinjiga koordinater; SBP;

    Sammanfattning : In this thesis we look at acoustic wave propagation under water. We look in particular at waves generated by a point source and what happens with the propagation when we model the bottom as flat or as curvilinear. We assume the source to be working at a certain frequency and therefore we model this problem by solving the Helmholtz equation. LÄS MER

  5. 4. Evaluation, adaption and implementations of Perfectly Matched Layers in COMSOL Multiphysics

    Master-uppsats, KTH/Numerisk analys, NA

    Författare :Simon Erlandsson; [2020]
    Nyckelord :Applied mathematics; computational mathematics; finite element method; FEM; perfectly matched layer; PML; COMSOL; Tillämpad matematik; beräkningsteknik; finita elementmetoden; FEM; PML; COMSOL;

    Sammanfattning : Perfectly matched layer (PML) is a commonly used method of absorbing waves at a computational boundary for partial differential equation (PDE) problems. In this thesis, methods for improving the usability of implementations in Comsol Multiphysics is addressed. LÄS MER

  7. 5. Efficient Quadrature Settings for Elliptic PDE’s using a Coupled FEM and BEM Solver in COMSOL Multiphysics

    Master-uppsats, KTH/Numerisk analys, NA

    Författare :Gustav Friberg; [2014]
    Nyckelord :;

    Sammanfattning : By using singular integral kernels based on the fundamental solution, a partial differential equation (PDE) can be rewritten as a boundary integral defined at the boundary of a domain. This requires a linear differential operator with coefficients that are isotropic and homogeneous in space. LÄS MER