Sökning: "Beräkningsvetenskap med inriktning mot numerisk analys"

Visar resultat 1 - 5 av 41 avhandlingar innehållade orden Beräkningsvetenskap med inriktning mot numerisk analys.

  1. 1. Hybrid Methods for Unsteady Fluid Flow Problems in Complex Geometries

    Författare :Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hybrid methods; finite difference methods; finite volume methods; coupling procedure; stability; efficiency; artificial dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Beräkningsvetenskap med inriktning mot numerisk analys;

    Sammanfattning : In this thesis, stable and efficient hybrid methods which combine high order finite difference methods and unstructured finite volume methods for time-dependent initial boundary value problems have been developed. The hybrid methods make it possible to combine the efficiency of the finite difference method and the flexibility of the finite volume method. LÄS MER

  3. 2. Stable and High-Order Finite Difference Methods for Multiphysics Flow Problems

    Författare :Jens Berg; Jan Nordström; Per Lötstedt; David Zingg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Summation-by-parts; Simultaneous Approximation Term; Stability; High-order accuracy; Finite difference methods; Dual consistency; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Partial differential equations (PDEs) are used to model various phenomena in nature and society, ranging from the motion of fluids and electromagnetic waves to the stock market and traffic jams. There are many methods for numerically approximating solutions to PDEs. LÄS MER

  4. 3. Efficient Simulation of Wave Phenomena

    Författare :Martin Almquist; Ken Mattsson; Gianluca Iaccarino; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite difference method; high-order accuracy; stability; summation by parts; simultaneous approximation term; quantum mechanics; Dirac equation; local time-stepping; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Wave phenomena appear in many fields of science such as acoustics, geophysics, and quantum mechanics. They can often be described by partial differential equations (PDEs). As PDEs typically are too difficult to solve by hand, the only option is to compute approximate solutions by implementing numerical methods on computers. LÄS MER

  5. 4. On Numerical Solution Methods for Block-Structured Discrete Systems

    Författare :Petia Boyanova; Maya Neytcheva; Oleg Iliev; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Preconditioning techniques; Finite element method; Two-by-two block matrices; Optimal order methods; AMLI method; Cahn-Hilliard equation; Multiphase flow; Inexact Newton method; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The development, analysis, and implementation of efficient methods to solve algebraic systems of equations are main research directions in the field of numerical simulation and are the focus of this thesis. Due to their lesser demands for computer resources, iterative solution methods are the choice to make, when very large scale simulations have to be performed. LÄS MER

  7. 5. 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