Sökning: "Turbulence modelling"

Visar resultat 1 - 5 av 118 avhandlingar innehållade orden Turbulence modelling.

  1. 1. 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

  3. 2. Turbulence Modelling of Flows Related to Wall-Cooling Applications

    Författare :Stefan Jansson; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Modelling and simulation of turbulence subject to system rotation

    Författare :Olof Grundestam; Arne Johansson; Sharath Girimaji; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  5. 4. 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

  7. 5. Experimental and computational studies of turbulent separating internal flows

    Författare :Olle Törnblom; Arne V. Johansson; Michel Stanislas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; turbulence; flow separation; turbulence modelling; asymmetric diffuser; boundary layer; PIV; vortex generator; separation control; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : The separating turbulent flow in a plane asymmetric diffuser with 8.5 degrees opening angle is investigated experimentally and computationally. The considered flow case is suitable for fundamental studies of separation, separation control and turbulence modelling. LÄS MER