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Visar resultat 1 - 5 av 36 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Turbulence Measurements in a Natural Convection Boundary Layer and a Swirling Jet

    Författare :Abolfazl Shiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swirl; constant current bridge; high Rayleigh number; natural convection; Jet; cold-wire thermometry; vertical cylinder; laser Doppler anemometry; turbulent boundary layers;

    Sammanfattning : Two sets of experimental measurement were carried out on an axisymmetric swirling jet flow and a natural convection boundary layer. In the first experiment, the far field of an incompressible swirling jet, discharged into a quiescent ambient has been studied using laser Doppler anemometry. LÄS MER

  3. 2. Creation and destruction of in-cylinder flows : Large eddy simulations of the intake and the compression strokes

    Författare :Martin Söder; Laszlo Fuchs; Angelo Onorati; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirl; Tumble; Compression; Engine; LES; CFD; engine turbulence; engine simulations; intake flow structures; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The aim of this thesis is to increase engine efficiency by studying the flow structures created in an engine cylinder during the intake phase and the effect of the subsequent compression.The invention of the combustion engine has enabled three centuries of economic growth fueled by energy stored as hydrocarbons. LÄS MER

  4. 3. Turbulent Shear Flow Experiments: Design of Natural Convection Rig and LDA Measurement in Swirling Jets

    Författare :Abolfazl Shiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Self-Similar Solution; Natural Convection Boundary Layer; Axisymmetric Jet; Laser Doppler Anemometry; Swirl Number;

    Sammanfattning : This work consist of two sections. In the first part, a facility has been installed and modified from an existing rig in order to measure velocity and temperature field of axisymmetric turbulent natural convection boundary layers. With using laser doppler anemometry and cold wire resistance thermometry. LÄS MER

  5. 4. Numerical Modeling of Flows Related to Gas Turbine Combustors

    Författare :Robert-Zoltán Szász; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plasma; fluid dynamics; plasmas; Gaser; fluiddynamik; Gases; vortex breakdown; swirl; CFD; gas turbine;

    Sammanfattning : The thesis focuses on the numerical simulation of the flow field in gas turbine burners. Due to tougher and tougher requirements on low levels of emission of pollutants there is a need for new combustion technologies. In gas turbines one method to attain low pollutant levels is the use of lean premixed combustion. LÄS MER

  7. 5. Turbulent Swirl Flow Modeling for Combustor Applications

    Författare :Andrej V. Smirnov; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Numerical simulations of three-dimensional confined swirl flows in a combustion chamber geometry are carried out with improved turbulence and combustion models. In the first part of the work a comparative study of six turbulence models is done in application to swirl flow. LÄS MER