Search for dissertations about: "periodic boundary condition"

Showing result 1 - 5 of 22 swedish dissertations containing the words periodic boundary condition.

2. 1. Optimisation and control of boundary layer flows

   Author : Antonios Monokrousos; Dan S. Henningson; Per Lötstedt; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; control; estimation; optimal disturbances; Lagrange method; Engineering mechanics; Teknisk mekanik;

   Abstract : Both optimal disturbances and optimal control are studied by means of numerical simulations for the case of the flat-plate boundary-layer flow. The optimisation method is the Lagrange multiplier technique where the objective function is the kinetic energy of the flow perturbations and the constraints involve the linearised Navier–Stokes equations. READ MORE

4. 2. Moisture Transport in Porous Media. Modelling Based on Kirchhoff Potentials

   Author : Jesper Arfvidsson; Avdelningen för Byggnadsfysik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moisture distribtion; wood drying; wood; diffusion coefficient; numerical modelling; moisture flow; Moisture; transient measurements; periodic boundary condition; penetration depth; sorption coefficient; non-linear moisture flow; calculation model; anisitropy; Kirchhoff potentials; evaluation; moisture transport; Building construction; Byggnadsteknik;

   Abstract : The work presented in this thesis is focused on the development of the new concept to describe isothermal moisture transport using Kirchhoff potentials. The first four papers deal with moisture transport in porous media using Kirchhoff potentials. The last three papers deal with wood. READ MORE

5. 3. Scattering and propagation of electromagnetic waves in planar and curved periodic structures - applications to plane wave filters, plane wave absorbers and impedance surfaces

   Author : Ola Forslund; KTH; []
   Keywords : electromagnetic scattering; periodic structure; frequency selectiove structure; frequency selective surface;

   Abstract : The subject of this thesis is scattering of electromagneticwaves from planar and curved periodic structures. The problemspresented are solved in the frequency domain.Scattering from planar structures with two-dimensionalperiodic dependence of constitutive parameters is treated. READ MORE

6. 4. Scaling effects and homogenization of reaction-diffusion problems with nonlinear drift

   Author : Vishnu Raveendran; Adrian Muntean; Irina Pettersson; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; homogenization; asymptotic expansion with drift; two-scale convergence with drift; effective transmission condition; dimension reduction; two-scale system; nonlinear dispersion; Matematik; Mathematics;

   Abstract : We study the periodic homogenization of reaction-diffusion problems with nonlinear drift describing the transport of interacting particles in composite materials. The microscopic model is derived as the hydrodynamic limit of a totally asymmetric simple exclusion process for a population of interacting particles crossing a domain with obstacles. READ MORE

7. 5. A structural study into the boundary surface and associated curvature of three-dimensional mesoporous silica crystals

   Author : Keiichi Miyasaka; Osamu Terasaki; Reinhard Nesper; Stockholms universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mesoporous crystal; electron crystallography; electrostatic potential map; equi-potential surface; curvature; multiplly-twinned particle; Chemistry; Kemi; Structural Chemistry; strukturkemi;

   Abstract : Since their first discovery in the early 1990s, mesoporous crystals (MCs) have fascinated researchers in various fields because of their interesting structures and their potential uses. Electron crystallography (EC) gives the direct three-dimensional (3D) realization of a crystal as a reconstructed electrostatic potential map (EPM). READ MORE