Sökning: "Navier-Stokes"

Visar resultat 21 - 25 av 211 avhandlingar innehållade ordet Navier-Stokes.

  1. 21. 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

  3. 22. Initial-Boundary-Value Problems for the Stokes and Navier–Stokes Equations on Staggered Grids

    Författare :Jonas Nilsson; Bertil Gustafsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stokes equations; Navier-Stokes equations; boundary conditions; staggered grids; higher-order methods; Numerical Analysis; Numerisk analys;

    Sammanfattning : In the first part of the thesis various types of boundary conditions for the steady state Stokes equations are considered. We formulate the boundary conditions in a new way, such that the boundary value problem becomes non-singular, and derive estimates of the solution. LÄS MER

  4. 23. Modeling of Unsteady Flow Effects in Throughflow Calculations

    Författare :Magnus Stridh; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rotor-stator interaction; mixing-plane; linear Navier-Stokes; cascade; turbomachinery; transport equation; Linear harmonic; compressor; throughflow; turbine; Deterministic stress terms;

    Sammanfattning : In this work an evaluation of a deterministic stress transport model and a linearized Navier-Stokes harmonic approach for including unsteady effects in the steady mixing-plane computations of a multistage transonic compressor has been performed. The results of these two models are compared with those of time-average time-accurate solutions. LÄS MER

  5. 24. Modeling Unsteady flow Effects in 3D Throughflow Calculations

    Författare :Magnus Stridh; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughflow; turbomachinery; mixing-plane; rotor-stator interaction; cascade; Deterministic stress terms; Linear harmonic; compressor; preconditioned GMRES; Unsteady; linear Navier-Stokes; turbine;

    Sammanfattning : The flow field in a transonic multistage compressor is compressible, three-dimensional and highly unsteady and can be predicted in principle by the exact time-accurate Navier-Stokes equations. The high Reynolds number encountered in multistage turbomachinery together with the wall-bounded nature of the flow environment however prevent the use of DNS to solve the exact N-S equations. LÄS MER

  7. 25. High-order finite element methods for incompressible variable density flow

    Författare :Lukas Lundgren; Murtazo Nazarov; Anders Logg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite element method; artificial viscosity; Navier-Stokes equations; conservation properties; artificial compressibility; viscous regularization; variable density flow; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The simulation of fluid flow is a challenging and important problem in science and engineering. This thesis primarily focuses on developing finite element methods for simulating subsonic two-phase flows with varying densities, described by the variable density incompressible Navier-Stokes equations. LÄS MER