Sökning: "direct numerical simulation"

Visar resultat 6 - 10 av 123 avhandlingar innehållade orden direct numerical simulation.

  1. 6. Numerical study of flame dynamics

    Författare :Arkady Petchenko; Vitaly Bychkov; Leonid Kagan; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; combustion; Direct Numerical Simulation DNS ; turbulence; flame-vortex interaction; flame acceleration; flame-acoustic interaction; Physics; Fysik;

    Sammanfattning : Modern industrial society is based on combustion with ever increasing standards on the efficiency of burning. One of the main combustion characteristics is the burning rate, which is influenced by intrinsic flame instabilities, external turbulence and flame interaction with walls of combustor and sound waves. LÄS MER

  3. 7. Modelling Cavitation Mechanisms Using Large Eddy Simulation

    Författare :Nai Xian Lu; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrodynamics; Cavitation; cavitation erosion; cavitation mechanisms; numerical simulation; LES;

    Sammanfattning : Cavitation often brings negative effects such as performance degradation, noise and vibration, and material damage, being one of the limiting factors when designing propulsion systems. On the other hand, cavitation must be endured for an efficiently propelled system. LÄS MER

  4. 8. Detailed Numerical Simulations of Turbulent Premixed Flames at Moderate and High Karlovitz Numbers

    Författare :Henning Carlsson; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct numerical simulation; Large eddy simulation; Turbulent premixed combustion; Flow-flame interaction; High Karlovitz number;

    Sammanfattning : In generally accepted and applied flamelet combustion models, a turbulent flame is mainly assumed distorted by the large-scale turbulence eddies, whereas small-scale turbulence effects on the local flamelet structures are neglected. However, in a lot of industrial applications rather high turbulent intensities are often imposed, which induce turbulence scales at ranges smaller than the flame thickness. LÄS MER

  5. 9. Large eddy simulation of cavitating and non-cavitating flow

    Författare :Tobias Huuva; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high Reynolds number; Cavitation; turbulence; RANS; hydrodynamics; numerical simulation; modelling; DES; LES;

    Sammanfattning : Most marine configurations are subject to a number of complex and important hydrodynamic phenomena affecting the overall performance of the vessel, both regarding resistance and propulsive efficiency. In this thesis, the possibility of numerically simulating some of these phenomena is investigated. LÄS MER

  7. 10. Numerical studies of turbulent flames in wall-jet flows

    Författare :Zeinab Pouransari; Arne V. Johansson; Yves D'Angelo; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; combustion; direct numerical simulation; wall-jet; heat release effects; mixing scales; non-premixed flame; wall heat transfer; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : The present thesis deals with the fundamental aspects of turbulent mixing and non-premixed combustion in the wall-jet flow, which has a close resemblance to many industrial applications. Direct numerical simulations (DNS) of turbulent wall-jets with isothermal and exothermic reactions are performed. LÄS MER