Sökning: "subgrid modelling"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden subgrid modelling.

  1. 1. Modelling of Turbulent Flow and Heat Transfer for Building Ventilation

    Författare :Peng Shia-Hui; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; large eddy simulation; turbulent buoyant convection; ventilation performance assessment; purging flow rate; SGS modelling; ventilation flow; stochastic Markov chain model; turbulence modelling; LRN k-w model; two-equation models; building ventilation; transfer probability; transition regime; modified SGS buoyancy model; energy backscatter;

    Sammanfattning : This thesis contributes to studies on the assessment of building ventilation performance and the development of turbulence models accounting for Low-Reynolds-number (LRN) effects and buoyant convection with heat transfer. Assessments of building ventilation performance are discussed with respect to indoor air distribution and passive contaminant dispersion. LÄS MER

  3. 2. Anisotropy-resolving subgrid-scale modelling using explicit algebraic closures for large eddy simulation

    Författare :Amin Rasam; Arne Johansson; Bernard Geurts; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; large eddy simulation; explicit algebraic subgridscale model; passive scalar; stochastic modelling; periodic hill flow; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The present thesis deals with the development and performance analysis ofanisotropy-resolving models for the small, unresolved scales (”sub-grid scales”,SGS) in large eddy simulation (LES). The models are characterised by a descriptionof anisotropy by use of explicit algebraic models for both the subgridscale(SGS) stress tensor (EASSM) and SGS scalar flux vector (EASSFM). LÄS MER

  4. 3. Subgrid-scale modelling for large-eddy simulation including scalar mixing in rotating turbulent shear flows

    Författare :Linus Marstorp; Arne Johansson; Lars-Erik Eriksson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; large-eddy simulation; subgrid-scale model; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : The aim of the present study is to develop subgrid-scale models that are relevant for complex flows and combustion. A stochastic model based on a stochastic Smagorinsky constant with adjustable variance and time scale is proposed. LÄS MER

  5. 4. Multiscale Simulation Methods for Thermoelectric Generators

    Författare :Olle Högblom; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Exhaust gas heat recovery; subgrid modelling; CFD; Thermoelectrics; Contact resistances;

    Sammanfattning : Rising energy prices and greater environmental awareness, along with stringent emissions legislation, in the automotive industry make it possible to introduce techniques in the aftertreatment system that have previously been unprofitable. One such technique, studied here, is heat recovery from exhaust gases using thermoelectric generators. LÄS MER

  7. 5. Modelling of subgrid-scale stress and passive scalar flux in large eddy simulations of wall bounded turbulent flows

    Författare :Linus Marstorp; Arne V. Johansson; Pierre Comte; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; large-eddy simulation; subgrid-scale model; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : The aim of the thesis is to develop and validate subgrid-scale models that are relevant for large eddy simulations of complex flows including scalar mixing. A stochastic Smagorinsky model with adjustable variance and time scale is developed by adding a stochastic component to the Smagorinsky constant. LÄS MER