Sökning: "turbulence properties"

Visar resultat 1 - 5 av 113 avhandlingar innehållade orden turbulence properties.

1. 1. Dynamic properties of two-dimensional and quasi-geostrophic turbulence

   Författare :Andreas Vallgren; Erik Lindborg; Guido Boffetta; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; two-dimensional turbulence; decaying turbulence; quasi-geostrophic turbulence; direct numerical simulation DNS ; coherent vortices; energy cascade; enstrophy cascade; intermittency; massively parallel simulations; locality iii; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos;

   Sammanfattning : Two codes have been developed and implemented for use on massively parallelsuper computers to simulate two-dimensional and quasi-geostrophic turbulence.The codes have been found to scale well with increasing resolution and width ofthe simulations. LÄS MER

3. 2. Structures, Properties and Dynamics of Turbulent Vortices

   Författare :Farideh Ghasempour; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES.; Vortex structure; Turbulence; Vortex properties; Vortex dynamics;

   Sammanfattning : The development of models for several phenomena that occur in turbulent single- and multi-phase flows requires improved descriptions and quantifications of turbulent vortices. In many engineering applications, the time scale of these phenomena is equal to or smaller than the lifetime of turbulent vortices; consequently, they are not adequately described by using average turbulence properties. LÄS MER

4. 3. Droplet growth in atmospheric turbulence : A direct numerical simulation study

   Författare :Xiang-Yu (李翔宇) Li; Gunilla Svensson; Axel Brandenburg; Wojciech Grabowski; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cloud micro-physics; turbulence; inertial particles; DNS; condensation; collision; coalescence; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : This Ph.D. thesis examines the challenging problem of how turbulence affects the growth of cloud droplets in warm clouds. Droplets grow by either condensation or collision. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

7. 5. The Influence of Atmospheric Turbulence on Barrier Sound Reduction

   Författare :Jens Forssén; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER