Sökning: "jet stream"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden jet stream.

  1. 1. Experimental studies in jet flows and zero pressure-gradient turbulent boundary layers

    Författare :Ramis Örlü; P. Henrik Alfredsson; Tim B. Nickels; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Axisymmetric jet; swirling jet; coaxial jet; heated jet; zero pressuregradient turbulent boundary layer; wall-bounded turbulent flows; overlap region; passive scalar mixing; hot-wire anemometry; spatial resolution.; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : This thesis deals with the description and development of two classical turbulent shear flows, namely free jet and flat plate turbulent boundary layer flows. In both cases new experimental data has been obtained and in the latter case comparisons are also made with data obtained from data bases, both of experimental and numerical origin. LÄS MER

  3. 2. On Turbulence Modelling for Bilge Vortices: A Test of Eight Models for Three Cases

    Författare :Urban Svennberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wake; turbulence modelling; nonlinear eddy-viscosity model; bilge vortices; ship flow; jet; Navier-Stokes equation; two-equation model; Reynolds stress model; vortex;

    Sammanfattning : This work is a test, in three steps, of turbulence models for the calculation of the flow field around ships. Eight models ranging from k-e and k-w models to a Reynolds-stress model (RSM) are tested. LÄS MER

  4. 3. Large Eddy Simulation for the Analysis of Supersonic Jet Noise Suppression Devices

    Författare :Markus Olander Burak; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluidic injection; mixer-ejector; jet noise; Kirchhoff; forward flight effects; LES; acoustic liner; supersonic turbulent jets; broadband time-domain impedance boundary condition; chevrons; shock-associated noise; CAA; aeroacoustics;

    Sammanfattning : Stricter noise regulations for commercial and military aircraft have increased interest in noise reduction techniques within the aerospace industry. To meet the requirements, new noise suppression technologies have to be developed and numerical methods need to be validated and possibly improved for the correct assessment of these technologies. LÄS MER

  5. 4. Experimental and Numerical Investigations of Confluent Round Jets

    Författare :Klas Svensson; Bahram Moshfegh; Patrik Rohdin; Bengt Sundén; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Confluent jets; Multiple jet array; Jet interactions; Confluent Core Zone CCZ ; Particle Image Velocimetry PIV ; Laser Doppler Velocimetry LDA ; Computational Fluid Dynamics CFD ; Response Surface Methodology;

    Sammanfattning : Unconfined multiple interacting confluent round jets are interesting from a purely scientific point of view, as interaction between neighboring jets brings additional complexity to the flow field. Unconfined confluent round jets also exist in various engineering applications, such as ventilation supply devices, sewage disposal systems, combustion burners, chemical mixing or chimney stacks. LÄS MER

  7. 5. Stability analysis and transition prediction of wall-bounded flows

    Författare :Ori Levin; KTH; []
    Nyckelord :Boundary layer; wall jet; algebraic growth; exponential growth; lift-up effect; streamwise streaks; Tollmien-Schlichting waves; free-stream turbulence; roughness element; transition prediction; Parabolized Stability Equations; Direct Numerical S;

    Sammanfattning : Disturbances introduced in wall-bounded .ows can grow andlead to transition from laminar to turbulent .ow. In order toreduce losses or enhance mixing in energy systems, afundamental understanding of the . LÄS MER