Sökning: "direct numerical simulation"

Visar resultat 1 - 5 av 123 avhandlingar innehållade orden direct numerical simulation.

  1. 1. 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

  3. 2. Direct numerical simulation of turbulent flow in plane and cylindrical geometries

    Författare :Jukka Komminaho; KTH; []
    Nyckelord :turbulence; plane Couette flow; pipe flow; laminar-turbulent transition; direct numerical simulation; spectral methods;

    Sammanfattning : This thesis deals with numerical simulation of turbulentflows in geometrically simple cases. Both plane and cylindricalgeometries are used. The simplicity of the geometry allows theuse of spectral methods which yield a very high accuracy usingrelatively few grid points. A spectral method for planegeometries is implemented on a parallel computer. LÄS MER

  4. 3. Studies of turbulent boundary layer flow throughdirect numerical simulation

    Författare :Martin Skote; KTH; []
    Nyckelord :Turbulence; direct numerical simulation; boundary layer; separation; parallel computers; turbulence modelling;

    Sammanfattning : .... LÄS MER

  5. 4. Direct numerical simulation of turbulent premixed flames at high Karlovitz numbers: structure and modelling

    Författare :Thommie Nilsson; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct numerical simulation; Computational fluid dynamics; Combustion model; Premixed flame; Turbulence; Karlovitz number;

    Sammanfattning : There has been recent increased interest in premixed flames and in particular for use in gas turbines for power generation. This is a development that follows from increasing demands for high efficiency and low emissions of NOx, which can be achieved by using premixed flames and lean pre-heated mixtures, often close to the lean flammability limit. LÄS MER

  7. 5. Fundamental studies of non-premixed combustion in turbulent wall jets using direct numerical simulation

    Författare :Zeinab Pouransari; V. Arne Johansson; Christer Fureby; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; non-premixed combustion; global reaction; direct numerical simulation; wall-jet; heat release; mixing scales; heat transfer; Other engineering mechanics; Övrig teknisk mekanik;

    Sammanfattning : The present thesis deals with the fundamental aspects of turbulent mixingand non-premixed combustion in wall-jet flows. Direct numerical simulations(DNS) of compressible turbulent flows are performed in a wall-jet configura-tion, which has a close resemblance to many industrial combustion applica-tions. LÄS MER