Sökning: "Flame instabilities"

Visar resultat 6 - 10 av 13 avhandlingar innehållade orden Flame instabilities.

  1. 6. Swirl stabilized premixed flame analysis using of LES and POD

    Författare :Piero Iudiciani; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Precessing Vortex Core; Swirl stabilization; Lean Premixed Combustion; Proper Orthogonal Decomposition; Large Eddy Simulation;

    Sammanfattning : For environmental and human health reasons, the regulations on the emissions from combustion devices are getting more and more strict. In particular, it is important to abate the emission of pollutants deriving from combustion in gas turbines. A solution is the use of swirl stabilized, lean premixed combustion. LÄS MER

  3. 7. A Linearized Navier-Stokes Equations Methodology for Aeroacoustic and Thermoacoustic Simulations

    Författare :Wei Na; Susann Boij; Gunilla Efraimsson; Niklas Andersson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Linearized Navier-Stokes Equations LNSE ; frequency domain; tube row heat exchanger; hybrid liner; thermoacoustic instabilities; entropy waves; Rijke-tube; nozzle; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : Aeroengine noise is one of the dominating noise sources in today’s aircraft. Reduction of the aeroengine noise is related to multiphysics phenomena, and that is subject to different mechanisms, e.g., the coupling between turbulence, flame and sound waves. LÄS MER

  4. 8. Entrained flow gasification of biomass: soot formation and flame stability

    Författare :Burak Göktepe; Kevin Whitty; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy Engineering; Energiteknik;

    Sammanfattning : Entrained flow gasification (EFG) is a well-proven, commercially available technology for large scale coal gasification processes, with a production of a high quality syngas (a mixture of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), methane (CH4) and other compounds). For biomass, the process is still under development and there are several hurdles that must be cleared before it can become commercial. LÄS MER

  5. 9. Analysis of flow dynamics and flame stabilization in gas turbine related combustors

    Författare :Erdzan Hodzic; Strömningsteknik; []
    Nyckelord :LES; gas turbine; bluff-body; blow-off; swirl; POD; DMD; wavelet;

    Sammanfattning : The regulations on the emissions from combustion devices are getting more and more strict for environmental and human health reasons. Modern combustion research faces two major challenges; reduction of the pollutants, such as CO, NOx and unburnt hydro- carbons and increase of the combustion efficiency. LÄS MER

  7. 10. Large Eddy Simulation of Turbulent Premixed and Partially Premixed Combustion

    Författare :Eric Baudoin; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In this thesis, a computational fluid dynamics (CFD) approach is used to study turbulent premixed and partially premixed combustion. The CFD approach is based on large eddy simulation (LES) in which the large-scale structures of the flow are resolved on a grid, leaving only the small-scale structures (subgrid scales) to be modeled. LÄS MER