Sökning: "large-eddy simulation LES"

Visar resultat 6 - 10 av 127 avhandlingar innehållade orden large-eddy simulation LES.

  1. 6. Investigating aerosol effects on stratocumulus clouds through large-eddy simulation

    Författare :Ines Bulatovic; Annica Ekman; Caroline Leck; Ilona Riipinen; Daniel Grosvenor; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerosol particles; stratocumulus; mixed-phase clouds; cloud microphysics; cloud radiative effects; Arctic; Arctic amplification; LES; aerosolpartiklar; stratusmoln; underkylda vattendroppar och iskristaller; molnmikrofysik; molnstrålningseffekter; Arktis; ”large-eddy simulation”; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

    Sammanfattning : Clouds have a large impact on Earth’s radiative budget by reflecting, absorbing and re-emitting radiation. They thus play a critical role in the climate system. Nevertheless, cloud radiative effects in a changing climate are highly uncertain. LÄS MER

  3. 7. Large Eddy Simulation of Turbulent Flows in Combustor Related Geometries

    Författare :Jessica Gullbrand; Institutionen för energivetenskaper; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; Energiforskning; Energy research; Cartesian grid; high order wall treatment; SGS models; turbulence; subgrid scale models; LES; Large Eddy Simulation; akustik; vibrationer; vakuumteknik; hydraulik; vibration and acoustic engineering; Maskinteknik; vacuum technology; hydraulics;

    Sammanfattning : Numerical simulations using Large Eddy Simulation (LES) are applied to turbulent swirling flow fields. The swirling motion is often introduced into combustors to act as flame holders or enhance the mixing between species. Different turbulence models capture the swirling motion more or less accurately. LÄS MER

  4. 8. Large Eddy Simulation of an Oscillating Cylinder

    Författare :Andreas Feymark; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical simulation; hydrodynamics; LES; subgrid modeling; forced oscillation;

    Sammanfattning : In this thesis Large Eddy Simulation of an Oscillating Cylinder is carried out studying the governing flow physics and modeling aspects such as effect of grid resolution and subgrid model. This also involves validation of the predictions with experimental data in terms of Fourier analysis, magnitude and characteristic shape of drag and lift force profiles. LÄS MER

  5. 9. 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

  7. 10. Large eddy simulation of combustion using linear-eddy subgrid modeling

    Författare :Salman Arshad; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES-LEM; splicing; turbulent combustion; super-grid LES-LEM; CFD; linear eddy model; reaction-rate closure; large eddy simulation;

    Sammanfattning : As emissions regulations are getting stricter and efficiency requirements of internal combustion engines (ICE) are increasing, different concepts to improve combustion are being investigated. For example lean stratified premixed combustion, homogeneous charge compression ignition (HCCI), use of more exhaust gas recirculation (EGR) to reduce NOx etc. LÄS MER