Search for dissertations about: "stokes equations"

Showing result 1 - 5 of 158 swedish dissertations containing the words stokes equations.

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

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

   Abstract : 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. READ MORE

4. 2. Boundary integral methods for Stokes flow : Quadrature techniques and fast Ewald methods

   Author : Oana Marin; Anna-Karin Tornberg; Anita Layton; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; boundary integral; Stokes flow; quadrature rule; Ewald decomposition;

   Abstract : Fluid phenomena dominated by viscous effects can, in many cases, be modeled by the Stokes equations. The boundary integral form of the Stokes equations reduces the number of degrees of freedom in a numerical discretization by reformulating the three-dimensional problem to two-dimensional integral equations to be discretized over the boundaries of the domain. READ MORE

5. 3. A Linearized Navier-Stokes Equations Methodology for Aeroacoustic and Thermoacoustic Simulations

   Author : Wei Na; Susann Boij; Gunilla Efraimsson; Niklas Andersson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Linearized Navier-Stokes Equations LNSE ; frequency domain; tube row heat exchanger; hybrid liner; thermoacoustic instabilities; entropy waves; Rijke-tube; nozzle; Engineering Mechanics; Teknisk mekanik;

   Abstract : Aeroengine noise is one of the dominating noise sources in today’s aircraft. Reduction of the aeroengine noise is related to multiphysics phenomena, and that is subject to different mechanisms, e.g., the coupling between turbulence, flame and sound waves. READ MORE

6. 4. Accuracy, efficiency and robustness for rigid particle simulations in Stokes flow

   Author : Anna Broms; Anna-Karin Tornberg; Mattias Sandberg; Eric Keaveny; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Stokes flow; rigid particles; accuracy; fundamental solutions; method of images; multiblob; contact avoiding; complementarity problem; barrier method; elliptic PDE; grid optimisation; pair-correction; boundary integral equations; Stokesflöde; noggrannhet; stela partiklar; fundamentallösningar; randintegralekvation; reflektionspunkter; multiblob; kontaktundvikande algoritmer; komplementaritetsproblem; barriärmetod; elliptisk PDE; gridoptimering; parkorrektion; Numerical Analysis; Numerisk analys;

   Abstract : The thesis concerns simulation techniques for systems of nano- to micro-scaled rigid particles immersed in a viscous fluid, ubiquitous in nature and industry. With negligible fluid inertia, the set of PDEs known as the Stokes equations can be used to model the hydrodynamics. READ MORE

7. 5. Frequency Domain Linearized Navier-Stokes Equations Methodology for Aero-Acoustic and Thermoacoustic Simulations

   Author : Wei Na; Gunilla Efraimsson; Susann Boij; Martinez Lera Paula; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Linearized Navier-Stokes Equations; frequency domain; fluid equivalent model; hybrid liner; thermoacoustic instabilities; Rijke-tube; Engineering Mechanics; Teknisk mekanik;

   Abstract : The first part of the thesis focuses on developing a numerical methodology to simulate the acoustic properties of a hybrid liner consisting of a perforated plate, a porous layer and a Helmholtz cavity. Liners are always a standard way to reduce noise in today’s aeroengines, e.g. READ MORE