Sökning: "Multiscale"

Visar resultat 26 - 30 av 182 avhandlingar innehållade ordet Multiscale.

1. 26. Experimental validation and numerical upscaling of linear network models for simulation of paper

   Författare :Morgan Görtz; Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik (FCC); []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bending; paper model; multiscale; network model; local orthogonal decomposition; paper simulation;

   Sammanfattning : Paper modeling results in complex geometries that lead to enormous numerical problems. The complexity lies in the material's microstructure. Individual paper fibers must be considered for useful material simulations in paper development, where wood composition and other fiber-based parameters are essential. LÄS MER

3. 27. Dynamics of bubbles across scales

   Författare :Niklas Hidman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DNS; multiscale; lift force; scalar mixing; Bubbly flows; multiphase;

   Sammanfattning : This thesis presents numerical investigations of bubbly flow phenomena across a wide range of relevant spatial and temporal scales. The aim is to increase our understanding of a great variety of underlying phenomena and to facilitate improved predictions of bubbly flows at all relevant scales. LÄS MER

4. 28. Homogenization of Some Selected Elliptic and Parabolic Problems Employing Suitable Generalized Modes of Two-Scale Convergence

   Författare :Jens Persson; Anders Holmbom; Liselott Flodén; Marianne Lindberg; Mårten Gulliksson; Peter Wall; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; H-convergence; G-convergence; homogenization; multiscale analysis; two-scale convergence; multiscale convergence; elliptic partial differential equations; parabolic partial differential equations; monotone operators; heterogeneous media; non-periodic media; Mathematical analysis; Analys;

   Sammanfattning : The present thesis is devoted to the homogenization of certain elliptic and parabolic partial differential equations by means of appropriate generalizations of the notion of two-scale convergence. Since homogenization is defined in terms of H-convergence, we desire to find the H-limits of sequences of periodic monotone parabolic operators with two spatial scales and an arbitrary number of temporal scales and the H-limits of sequences of two-dimensional possibly non-periodic linear elliptic operators by utilizing the theories for evolution-multiscale convergence and λ-scale convergence, respectively, which are generalizations of the classical two-scale convergence mode and custom-made to treat homogenization problems of the prescribed kinds. LÄS MER

5. 29. On Computational Homogenization of Flow in Porous Media

   Författare :Carl Sandström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiscale; porous media; stokes flow; FE2; computational homogenization; darcy flow;

   Sammanfattning : Porous materials are present in many natural as well as engineered structures. Engineering examples of porous materials include sandstone in which oil can be stored, earth dams, composite materials, air filters and sanitary products with fiber networks (e.g. diapers). LÄS MER

7. 30. Numerical homogenization of network models and micro-mechanical simulation of paperboard

   Författare :Morgan Görtz; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; domain decomposition; paper model; local orthogonal decomposition; Bending; paper simulation; network model; multiscale;

   Sammanfattning : Micro-mechanical simulations of paper products involve complex geometries and challenging numerical problems. This work considers micro-mechanical simulations where individual paper fibers are modeled and resolved. This level of detail is useful in paper-product development, where wood composition and other fiber-based parameters are essential. LÄS MER