Sökning: "SGS model"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden SGS model.

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. Large-Eddy Simulation for Computing the Flow Around Vehicles

   Författare :Sinisa Krajnovic; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; LES; Subgrid scale model; Bus; SGS model; Car; Vehicle; Large eddy simulation;

   Sammanfattning : The feasibility of the use of large-eddy simulation (LES) in external vehicle aerodynamics is investigated. The computational requirement for LES of the full size car at road conditions is beyond the capability of computers in the near future. Since LES cannot be used for quantitative prediction of this flow, i.e. LÄS MER

4. 3. Large Eddy Simulation of Turbulent Flows in Combustor Related Geometries

   Författare :Jessica Gullbrand; Institutionen för energivetenskaper; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; Energiforskning; Energy research; Cartesian grid; high order wall treatment; SGS models; turbulence; subgrid scale models; LES; Large Eddy Simulation; akustik; vibrationer; vakuumteknik; hydraulik; vibration and acoustic engineering; Maskinteknik; vacuum technology; hydraulics;

   Sammanfattning : Numerical simulations using Large Eddy Simulation (LES) are applied to turbulent swirling flow fields. The swirling motion is often introduced into combustors to act as flame holders or enhance the mixing between species. Different turbulence models capture the swirling motion more or less accurately. LÄS MER

5. 4. Numerical and modelling aspects of large-eddy and hybrid simulations of turbulent flows

   Författare :Matteo Montecchia; Arne V. Johansson; Gert Brethouwer; Stefan Wallin; Dominic Von Terzi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; wall-bounded flows; large-eddy simulation; SGS modelling; OpenFOAM; hybrid RANS-LES; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : In this study, the explicit algebraic sub-grid scale (SGS) model (EAM) has been extensively validated in wall-resolved large-eddy simulations (LES) of wall-bounded turbulent flows at different Reynolds numbers and a wide range of resolutions. Compared to eddy-viscosity based models, the formulation of the EAM is more consistent with the physics and allows to accurately capture SGS anisotropy,which is relevant especially close to walls. LÄS MER

7. 5. Large Eddy Simulation of Turbulent Swirling Flows and Turbulent Premixed Combustion

   Författare :Ping Wang; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid dynamics; Gases; flamelet model; flame wrinkle; large eddy simulation; vortex breakdown; turbulent premixed combustion; level set G-equation; swirling flow; plasmas; Gaser; fluiddynamik; plasma; Energy research; Energiforskning;

   Sammanfattning : With the increasing concerns about our environment and human health, more and more stringent emission limits have been specified. These adopted and still coming emission limits require and promote more accurate, less experiential methods to design and develop the combustors. LÄS MER