Advanced search

Showing result 1 - 5 of 12 swedish dissertations matching the above criteria.

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

    Author : Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Summation-by-Parts Operators for High Order Finite Difference Methods

    Author : Ken Mattsson; Nordström Jan; Gunilla Kreiss; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dinite difference methods; accuracy; stability; dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Numerical Analysis;

    Abstract : High order accurate finite difference methods for hyperbolic and parabolic initial boundary value problems (IBVPs) are considered. Particular focus is on time dependent wave propagating problems in complex domains. Typical applications are acoustic and electromagnetic wave propagation and fluid dynamics. READ MORE

  5. 3. The Finite Difference Methods for Multi-phase Free Boundary Problems

    Author : Avetik Arakelyan; Henrik Shahgholian; John W. Barrett; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MATHEMATICS; MATEMATIK;

    Abstract : This thesis consist of an introduction and four research papers concerning numerical analysis for a certain class of free boundary problems. Paper I is devoted to the numerical analysis of the so-called two-phase membrane problem. Projected Gauss-Seidel method is constructed. READ MORE

  6. 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 : 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

  7. 5. Error Analysis and Smoothing Properties of Discretized Deterministic and Stochastic Parabolic Problems

    Author : Yubin Yan; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In this thesis we consider smoothing properties and approximation of time derivatives for parabolic equations and error estimates for stochastic parabolic partial differential equations approximated by the finite element method. In the first two papers, we study smoothing properties and approximation of the time derivative in time discretization schemes with constant and variable time steps for an abstract homogeneous linear parabolic problem. READ MORE