Sökning: "Euler flow"

Visar resultat 1 - 5 av 42 avhandlingar innehållade orden Euler flow.

1. 1. 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

3. 2. 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

4. 3. Data Assimilation in Fluid Dynamics using Adjoint Optimization

   Författare :Johan Lundvall; Vladimir Kozlov; Per Weinerfelt; Matts Karlsson; Anders Szepessy; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Data assimilation; Inverse problem; Adjoint optimization; Burgers equation; nonlinear; Landweber; Initial pressure; Euler flow; Applied mathematics; Tillämpad matematik;

   Sammanfattning : Data assimilation arises in a vast array of different topics: traditionally in meteorological and oceanographic modelling, wind tunnel or water tunnel experiments and recently from biomedical engineering. Data assimilation is a process for combine measured or observed data with a mathematical model, to obtain estimates of the expected data. LÄS MER

5. 4. Realistic simulations of delta wing aerodynamics using novel CFD methods

   Författare :Stefan Görtz; Arthur Rizzi; Miguel Visbal; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; CFD; aerodynamics; flow physics; steady; unsteady; delta wing; vortical flow; Rymd- och plasmafysik; Space physics; Rymdfysik;

   Sammanfattning : The overall goal of the research presented in this thesis is to extend the physical understanding of the unsteady external aerodynamics associated with highly maneuverable delta-wing aircraft by using and developing novel, more efficient computational fluid dynamics (CFD) tools. More specific, the main purpose is to simulate and better understand the basic fluid phenomena, such as vortex breakdown, that limit the performance of delta-wing aircraft. 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