Search for dissertations about: "turbulence"

Showing result 36 - 40 of 691 swedish dissertations containing the word turbulence.

2. 36. Transport, Turbulence and Instabilities in Cosmic Magnetic Fields

   Author : Giuseppe Di Bernardo; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cosmic Rays; Interstella Medium; Galactic Magnetic Fields; Magnetohydrodynamics Turbulence; Accretion Discs;

   Abstract : This decade has seen a large number of space missions, which, alongside ground-based radio, optical and gamma-ray telescopes, have enabled a deep insight into the non-thermal astrophysical environments. Interstellar Medium (ISM), Supernovae Remnants (SNRs) and Black-Hole (BH) accretion discs (ADs) are only a few examples of natural habitat of interaction of relativistic particles and magnetic fields, largely mediated by the action of the turbulence. READ MORE

4. 37. 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

5. 38. Numerical Modelling of Diesel Spray Injection and Turbulence Interaction

   Author : Fabian Kärrholm Peng; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational Fluid Dynamics; Spray; Cavitation; Cavitation; Turbulence Model; AtomizationTurbulence Model; Diesel; Atomization;

   Abstract : It has been established by many authors that numerical simulations ofDiesel sprays, using a Lagrangian description for the liquid phase,are particularly sensitive to the scale of the computational cellscompromising the mesh. There have been many suggestions regardingmeans to reduce the dependency on the mesh by improving the componentsubmodels, but few have addressed the gas phase turbulence modelling. READ MORE

6. 39. 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

7. 40. The age of transported scalars in fluid mechanics

   Author : Federico Ghirelli; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; grate furnace; velocity correlation; fluid age; scalar age; turbulence model; residence time; energy spectrum; turbulence age;

   Abstract : Computational fluid dynamics (CFD) is applied to the reacting flow in the freeboard of a 30MW biofuel fired grate furnace and results are validated by comparison with data from an extensive measurement campaign. The influence of the fuel bed model on the results of the freeboard model is investigated. READ MORE