Sökning: "turbulence modification"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden turbulence modification.

  1. 1. Experimental study of passive scalar mixing in swirling jet flows

    Detta är en avhandling från Stockholm : KTH

    Författare :Ramis Örlü; KTH.; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; swirling jet; turbulence; passive scalar; mixing; hot-wire anemometry; cold-wire; TECHNOLOGY Engineering mechanics Fluid mechanics; TEKNIKVETENSKAP Teknisk mekanik Strömningsmekanik;

    Sammanfattning : Despite its importance in various industrial applications there is still a lack of experimental studies on the dynamic and thermal field of swirling jets in the near-field region. The present study is an attempt to close this lack and provide new insights on the effect of rotation on the turbulent mixing of a passive scalar, on turbulence (joint) statistics as well as the turbulence structure. LÄS MER

  2. 2. A Particle Image Velocimetry Study of Bubbly Gas-Liquid Flow

    Detta är en avhandling från Xiaoyun Tu, Division of Food Engineering, Department of Food Technology, Engineering and Nutrition

    Författare :Xiaoyun Tu; Lunds universitet.; Lund University.; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulent dispersion; Food and drink technology; Livsmedelsteknik; turbulence; Rushton turbine; stirred tank; slip velocity; bubbly gas liquid two-phase flow; coherent structure; CCD camera; PIV; POD;

    Sammanfattning : The aim of this work is to build a framework that can be used for characterizing the bubbly gas liquid turbulent flow in the stirred bioreactor tank. To this end we have developed and modified techniques with which to measure the velocity of both dispersed gas and carrier liquid phases by the optical measurement technique, a 2-CCD camera Particle Image Velocimetry (PIV) system; and to characterize the turbulence by the wavelets tool, Proper Orthogonal Decomposition (POD). LÄS MER

  3. 3. Secondary Electromagnetic Radiation Generated by HF Pumping of the Ionosphere

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Lars Norin; Uppsala universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; space physics; ionospheric modification experiments; plasma turbulence; stimulated electromagnetic emission; ionospheric irregularities; radio waves; parametric processes; thermal parametric instability; transient dynamics; wave-wave interactions; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik;

    Sammanfattning : Electromagnetic waves can be used to transmit information over long distances and are therefore often employed for communication purposes. The electromagnetic waves are reflected off material objects on their paths and interact with the medium through which they propagate. LÄS MER

  4. 4. CFD Modeling of Turbulent Flows in Industrial Applications with Emphasis on Premixed Combustion in Gas Turbines

    Detta är en avhandling från Department of Heat and Power Engineering, Lund university

    Författare :Ulf Engdar; Lunds universitet.; Lund University.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Motorer; turbulence and premixed combustion modeling ; CFD modeling ; level-set flamelet library approach ; emissions ; gas turbine ; compressor washing ; spray modeling ; Technological sciences; Teknik; Energy research; Energiforskning; Thermal engineering; applied thermodynamics; Termisk teknik; Motors and propulsion systems; termodynamik;

    Sammanfattning : Increasing restrictions on hazardous emissions combined with demands for good profitability from the operators in the energy market have contributed strongly to the development of innovations in which the emphasis is on low emissions and high efficiency. For gas turbine-based power plants, emission of NOx in particular is governed by stringent legislation. LÄS MER

  5. 5. Enhanced Radar Backscatter from the Ionosphere

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Nicola Schlatter; KTH.; [2013]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Incoherent scatter radars are powerful ground based instruments for ionospheric measurements. By analysis of the Doppler shifted backscatter spectrum, containing the signature of electrostatic plasma waves, plasma bulk properties are estimated. LÄS MER