Search for dissertations about: "On Turbulence Modelling"

Showing result 1 - 5 of 107 swedish dissertations containing the words On Turbulence Modelling.

2. 1. The Influence of Atmospheric Turbulence on Barrier Sound Reduction

   Author : Jens Forssén; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; traffic noise; barrier; measurements; turbulence; scattering cross-section; substitute sources; outdoor sound propagation; parabolic equation method; random media; numerical modelling;

   Abstract : Numerical modelling and measurements are used for studying the reduced performance of a noise barrier, caused by a turbulent atmosphere. The turbulence scatters the sound, which leads to an increased noise level in the acoustic shadow region behind the barrier. READ MORE

4. 2. Time Spectral Methods - Towards Plasma Turbulence Modelling

   Author : Kristoffer Lindvall; Jan Scheffel; Carl Sovinec; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fusion; Turbulence; Micro-instabilities; Time-spectral; Navier-Stokes; MHD; Weiland model; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Energy comes in two forms; potential energy and kinetic energy. Energyis stored as potential energy and released in the form of kinetic energy. This process of storage and release is the basic strategy of all energy alternatives in use today. This applies to solar, wind, fossil fuels, and the list goes on. READ MORE

5. 3. On the modelling of turbulent flow and mixing in stirred reactors

   Author : Johan Revstedt; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; CFD; stirred reactors; impeller modelling; Energy research; mixing; LES; Energiforskning;

   Abstract : This thesis concerns the numerical simulations and modelling of the flow structure and scalar transport in stirred reactors. For this Large Eddy Simulations (LES) have been used. The flow situation in a stirred reactor includes several flow phenomena that are not well predicted by "standard" two-equation models, e.g. READ MORE

6. 4. Turbulence Modelling of Flows Related to Wall-Cooling Applications

   Author : Stefan Jansson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low-Reynolds number models; second-order-moment closures; turbulent heat transfer; two-equation models; film-cooling; near-wall models; turbulence modelling;

   Abstract : Engineering flows are generally characterised by complex strain field and turbulence structure arising from a combination of shear, curvature, separation and recirculation etc. Under such flow conditions, transport by turbulent velocity fluctuations can make a significant contribution to the transport of momentum, heat and mass. READ MORE

7. 5. Modelling and simulation of turbulence subject to system rotation

   Author : Olof Grundestam; Arne Johansson; Sharath Girimaji; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct numerical simulations; least-squares method; turbulence model; nonlinear modelling; system rotation; streamline curvature; high-lift aerodynamics; Fluid mechanics; Strömningsmekanik;

   Abstract : Simulation and modelling of turbulent flows under influence of streamline curvature and system rotation have been considered. Direct numerical simulations have been performed for fully developed rotating turbulent channel flow using a pseudo-spectral code. The rotation numbers considered are larger than unity. READ MORE