Sökning: "perforated domain"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden perforated domain.

1. 1. Homogenization in Perforated Domains

   Författare :Martin Strömqvist; Henrik Shahgholian; Scott Armstrong; KTH; []
   Nyckelord :Mathematics; Matematik;

   Sammanfattning : Homogenization theory is the study of the asymptotic behaviour of solutionsto partial differential equations where high frequency oscillations occur.In the case of a perforated domain the oscillations are due to variations in thedomain of the equation. LÄS MER

3. 2. Frequency Domain Linearized Navier-Stokes Equations Methodology for Aero-Acoustic and Thermoacoustic Simulations

   Författare :Wei Na; Gunilla Efraimsson; Susann Boij; Martinez Lera Paula; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. Some new results in homogenization of flow in porous media with mixed boundary condition

   Författare :Elena Miroshnikova; Andrey Piatnitski; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : The present thesis is devoted to derivation of Darcy’s Law for incompressible Newtonian fluid in perforated domains by means of homogenization techniques.The problem of describing flow in porous media occurs in the study of various physical phenomena such as filtration in sandy soils, blood circulation in capillaries etc. LÄS MER

5. 4. Homogenization of pseudoparabolic reaction-diffusion-mechanics systems : Multiscale modeling, well-posedness and convergence rates

   Författare :Arthur J. Vromans; Adrian Muntean; Claudia Timofte; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reaction-diffusion-mechanics system; parameter delimitation; parabolic-pseudoparabolic equations; weak solvability; Rothe method; periodic homogenization; corrector estimates; vanishing thin domains; Matematik; Mathematics;

   Sammanfattning : In this dissertation, parabolic-pseudoparabolic equations are proposed to couple chemical reactions, diffusion, flow and mechanics in heterogeneous materials using the framework of mixture theory. The weak solvability is obtained in a one dimensional setting for the full system posed in a homogeneous domain - a formulation which we have obtained using the classical mixture theory. LÄS MER

7. 5. Integral inequalities of Hardy and Friedrichs types with applications to homogenization theory

   Författare :Yulia Koroleva; Andrey Piatniski; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : This PhD thesis deals with some new integral inequalities of Hardy and Friedrichs types in domains with microinhomogeneous structure in a neighborhood of the boundary. The thesis consists of six papers (Paper A -- Paper F) and an introduction, which put these papers into a more general frame and which also serves as an overview of this interesting field of mathematics. LÄS MER