Sökning: "perfectly matched layer"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden perfectly matched layer.

  1. 1. Perfectly Matched Layers and High Order Difference Methods for Wave Equations

    Författare :Kenneth Duru; Gunilla Kreiss; Jan Nordsröm; Ken Mattsson; Marcus Grote; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elastic waves; Surface waves; Perfectly matched layers; High order difference methods; Stability; Summation-by-parts operators; Boundary treatments; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The perfectly matched layer (PML) is a novel technique to simulate the absorption of waves in unbounded domains. The underlying equations are often a system of second order hyperbolic partial differential equations. In the numerical treatment, second order systems are often rewritten and solved as first order systems. LÄS MER

  3. 2. Absorbing Layers and Non-Reflecting Boundary Conditions for Wave Propagation Problems

    Författare :Daniel Appelö; Prof. Gunilla Kreiss; Eliane Becache; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PML; perfectly matched layer; Numerical analysis; Numerisk analys;

    Sammanfattning : The presence of wave motion is the defining feature in many fields of application,such as electro-magnetics, seismics, acoustics, aerodynamics,oceanography and optics. In these fields, accurate numerical simulation of wave phenomena is important for the enhanced understanding of basic phenomenon, but also in design and development of various engineering applications. LÄS MER

  4. 3. High Order Finite Difference Methods with Artificial Boundary Treatment in Quantum Dynamics

    Författare :Anna Nissen; Gunilla Kreiss; Sverker Holmgren; Magnus Svärd; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Schrödinger equation; finite difference methods; perfectly matched layer; summation-by-parts operators; adaptive discretization; stability; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The investigation of the dynamics of chemical reactions, both from the theoretical and experimental side, has drawn an increasing interest since Ahmed H. Zewail was awarded the 1999 Nobel Prize in Chemistry for his work on femtochemistry. LÄS MER

  5. 4. Absorbing boundary techniques for the time-dependent Schrödinger equation

    Författare :Anna Nissen; Gunilla Kreiss; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Chemical dissociation processes are important in quantum dynamics. Such processes can be investigated theoretically and numerically through the time-dependent Schrödinger equation, which gives a quantum mechanical description of molecular dynamics.This thesis discusses the numerical simulation of chemical reactions involving dissociation. LÄS MER

  7. 5. Non-reflecting Boundary Conditions for Wave Propagation Problems

    Författare :Daniel Appelö; KTH; []
    Nyckelord :;

    Sammanfattning : We consider two aspects of non-reflecting boundaryconditions for wave propagation problems. First we evaluate aproposed Perfectly Matched Layer (PML) method for thesimulation of advective acoustics. It is shown that theproposed PML becomes unstable for a certain combination ofparameters. A stabilizing procedure is proposed andimplemented. LÄS MER