Search for dissertations about: "numerical scheme"

Showing result 21 - 25 of 298 swedish dissertations containing the words numerical scheme.

  2. 21. Stable High-Order Finite Difference Methods for Aerodynamics

    Author : Magnus Svärd; Jan Nordström; Thomas Hagstrom; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite difference methods; high-order accuracy; summation-by-parts; stability; energy estimates; finite volume methods; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Numerical Analysis;

    Abstract : In this thesis, the numerical solution of time-dependent partial differential equations (PDE) is studied. In particular high-order finite difference methods on Summation-by-parts (SBP) form are analysed and applied to model problems as well as the PDEs governing aerodynamics. READ MORE

  4. 22. Weak Boundary and Interface Procedures for Wave and Flow Problems

    Author : Qaisar Abbas; Jan Nordström; Peter Eliasson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; weak boundary conditions; multiple penalty; finite difference methods; summation-by-parts; high order scheme; hybrid methods; MUSCL scheme; shocks; stability; energy estimate; steady-state; non-reflecting; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : In this thesis, we have analyzed the accuracy and stability aspects of weak boundary and interface conditions (WBCs) for high order finite difference methods on Summations-By-Parts (SBP) form. The numerical technique has been applied to wave propagation and flow problems. READ MORE

  5. 23. Runge–Kutta Time Step Selection for Flow Problems

    Author : Karl Hörnell; Per Lötstedt; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Runge-Kutta; stepsize selection; optimization; flow problems; numerical analysis; Numerical Analysis; Numerisk analys;

    Abstract : Optimality is studied for Runge-Kutta iteration for solving steady-state and time dependent flow problems. For the former type an algorithm for determining locally optimal time steps is developed, based on the fact that the squared norm of the residual produced by an m-stage scheme is a 2m-degree polynomial, the coefficients of which can be computed from scalar products of Krylov subspace vectors. READ MORE

  6. 24. Numerical methods for quantum molecular dynamics

    Author : Katharina Kormann; Sverker Holmgren; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : The time-dependent Schrödinger equation models the quantum nature of molecular processes. Numerical simulations of these models help in understanding and predicting the outcome of chemical reactions. READ MORE

  7. 25. Development of Numerical Methods for Accurate and Efficient Scale-Resolving Simulations

    Author : Magnus Carlsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-order gradient reconstruction; Hybrid RANS-LES; Scale-resolving simulation; Synthetic Turbulence; Numerical methods; Turbulence modelling;

    Abstract : Hybrid RANS (Reynolds-Averaged Navier-Stokes)-LES (Large-Eddy Simulation) techniques are considered to be sufficiently accurate and computationally affordable for the aeronautical industry. Scale-resolving simulations is a powerful tool that can accurately predict complex unsteady compressible high-Reynolds-number turbulent flows, as often encountered aeronautical applications. READ MORE