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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. On Steady Water Waves and Flows with Vorticity in Three Dimensions

    Författare :Douglas Svensson Seth; Partiella differentialekvationer; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; The steady Euler equations; the water wave problem; fluid dynamics; partial differential equations;

    Sammanfattning : In this thesis we study the steady Euler equations in three dimensions where the solution is assumed to have nonvanishing vorticity. The thesis is based on three research papers. LÄS MER

  3. 2. Steady waves in local and nonlocal models for water waves

    Författare :Tien Truong; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics;

    Sammanfattning : We study the steady Euler equations for inviscid, incompressible, and irrotational water waves of constant density. The thesis consists of three papers. The first paper approaches the Euler equations through a famous nonlocal model equation for gravity waves, namely the Whitham equation. LÄS MER

  4. 3. A Linearized Euler Method for Unsteady Flow in Axial-Flow Turbomachines

    Författare :J. Pieter Groth; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : A linear Euler method for analysing unsteady inviscid compressible quasi three- dimensional flows in oscillating cascades is developed. It is applicable to both blade flutter and forced response problems. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER

  7. 5. Convergence Acceleration for Flow Problems

    Författare :Henrik Brandén; Sverker Holmgren; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational fluid dynamics; convergence acceleration; semicirculant preconditioning; fundamental solutions; Numerical Analysis; Numerisk analys;

    Sammanfattning : Convergence acceleration techniques for the iterative solution of system of equations arising in the discretisations of compressible flow problems governed by the steady state Euler or Navier-Stokes equations is considered. The system of PDE is discretised using a finite difference or finite volume method yielding a large sparse system of equations. LÄS MER