Search for dissertations about: "Gunilla Kreiss"

Showing result 1 - 5 of 29 swedish dissertations containing the words Gunilla Kreiss.

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

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

    Abstract : 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. READ MORE

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

    Author : Kenneth Duru; Gunilla Kreiss; Jan Nordsröm; Ken Mattsson; Marcus Grote; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; 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;

    Abstract : 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. READ MORE

  3. 3. Perfectly matched layers for second order wave equations

    Author : Kenneth Duru; Gunilla Kreiss; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : Numerical simulation of propagating waves in unbounded spatial domains is a challenge common to many branches of engineering and applied mathematics. Perfectly matched layers (PML) are a novel technique for simulating the absorption of waves in open domains. READ MORE

  4. 4. Stable Numerical Methods with Boundary and Interface Treatment for Applications in Aerodynamics

    Author : Sofia Eriksson; Jan Nordström; Gunilla Kreiss; Thomas Hagstrom; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; summation by parts; simultaneous approximation term; accuracy; stability; finite difference methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : In numerical simulations, problems stemming from aerodynamics pose many challenges for the method used. Some of these are addressed in this thesis, such as the fluid interacting with objects, the presence of shocks, and various types of boundary conditions. READ MORE

  5. 5. Computer-Assisted Proofs and Other Methods for Problems Regarding Nonlinear Differential Equations

    Author : Oswald Fogelklou; Warwick Tucker; Gunilla Kreiss; Piotr Zgliczynski; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; computer-assisted proof; numerical verification; viscous Burgers’ equation; enclosure; existence; nonlinear boundary value problems; Euler equations; inverse problem; bicubic spline; interval analysis; heat equation; fluid limit; peer-to-peer networks; fixed points; stability; global stability; Mathematics; Matematik;

    Abstract : This PhD thesis treats some problems concerning nonlinear differential equations. In the first two papers computer-assisted proofs are used. The differential equations there are rewritten as fixed point problems, and the existence of solutions are proved. READ MORE