Sökning: "Euler equation"

Visar resultat 11 - 15 av 57 avhandlingar innehållade orden Euler equation.

1. 11. Topics in Simulation and Stochastic Analysis

   Författare :Mikael Signahl; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik; stochastic heat equation; stochastic wave equation; error rates; truncated Levy process; discontinuities; optimal decay rate; digital communication system;

   Sammanfattning : Paper A investigates how to simulate a differentiated mean in cases where interchanging differentiation and expectation is not allowed. Three approaches are available, finite differences (FD's), infinitesimal perturbation analysis (IPA) and the likelihood ratio score function (LRSF) method. LÄS MER

3. 12. Numerical Computations with Fundamental Solutions

   Författare :Per Sundqvist; Henrik Brandén; Sverker Holmgren; Alison Ramage; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fundamental solution; partial differential equation; partial difference equation; iterative method; preconditioner; boundary method; Numerical Analysis; Numerisk analys;

   Sammanfattning : Two solution strategies for large, sparse, and structured algebraic systems of equations are considered. The first strategy is to construct efficient preconditioners for iterative solvers. The second is to reduce the sparse algebraic system to a smaller, dense system of equations, which are called the boundary summation equations. LÄS MER

4. 13. 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

5. 14. High order difference approximations for the linearized Euler equations

   Författare :Stefan Johansson; Bernhard Müller; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The computers of today make it possible to do direct simulation of aeroacoustics, which is very computational demanding since a very high resolution is needed.In the present thesis we study issues of relevance for aeroacoustic simulations. Paper A considers standard high order difference methods. LÄS MER

7. 15. On some Nonlinear Aspects of Wave Motion

   Författare :Erik Wahlén; Partiella differentialekvationer; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; water waves; bifurcation; global existence; rod equation; wabve breaking;

   Sammanfattning : In the first part of this thesis we consider the governing equations for capillary water waves given by the Euler equations with a free surface under the influence of surface tension over a flat bottom. We look for two-dimensional steady periodic waves. The problem is first transformed to a nonlinear elliptic equation in a rectangle. LÄS MER