Sökning: "numerical stability"

Visar resultat 16 - 20 av 350 avhandlingar innehållade orden numerical stability.

  1. 16. 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. 17. Numerical analyses of stability of a gradually raised tailings dam

    Författare :Muhammad Auchar Zardari; Daichao Sheng; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tailings dams; consolidation; rockfill berms; slope stability; corner; internal erosion; finite element analysis; Soil Mechanics; Geoteknik;

    Sammanfattning : Numerical analyses are presented in this thesis to address potential stability problems that may occur during gradual raisings and under seismic loading conditions of Aitik tailings dam in northern Sweden. The dam is mainly raised using upstream construction method. It is planned to raise the dam gradually in several stages. LÄS MER

  4. 18. High Order Finite Difference Methods in Space and Time

    Författare :Wendy Kress; Bertil Gustafsson; Gerald Warnecke; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite difference methods; Navier-Stokes equations; high order time discretization; deferred correction; stability; Numerical Analysis; Numerisk analys;

    Sammanfattning : In this thesis, high order accurate discretization schemes for partial differential equations are investigated. In the first paper, the linearized two-dimensional Navier-Stokes equations are considered. LÄS MER

  5. 19. Numerical simulation of the dynamics of a trapped molecular ion

    Författare :Avazeh Hashemloo; Claude Dion; Michael Drewsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diatomic molecular ion; linear Paul trap; rigid rotor; quantum rotational dynamics; wave-packet dynamics; time-dependent Schrödinger equation; stability;

    Sammanfattning : This thesis explores the dynamics of a heteronuclear diatomic molecular ion, possessing a permanent electric dipole moment, µ, which is trapped in a linear Paul trap and can interact with an off-resonance laser field. To build our model we use the rigid-rotor approximation, where the dynamics of the molecular ion are limited to its translational and rotational motions of the center-of-mass. LÄS MER

  7. 20. Numerical study on instability and interaction of wind turbine wakes

    Författare :Sasan Sarmast; Dan S. Henningson; Per-Åge Krogstad; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Turbines; CFD; EllipSys3D; Actuator Line; Stability; Wake; Vortex Model; SRA - E-Science SeRC ; SRA - E-vetenskap SeRC ;

    Sammanfattning : The optimization of new generation of the wind farms is dependent on our understanding of wind turbine wake development, wake dynamics and the interaction of the wakes. The overall goal of the optimization is decreasing the fatigue loading and increasing the power production of the wind farms. LÄS MER