Sökning: "vortex-shedding"

Visar resultat 6 - 10 av 23 avhandlingar innehållade ordet vortex-shedding.

  1. 6. Numerical Study of Laminar, Transitional and Turbulent Flow Past Rectangular Cylinders

    Författare :Ahmad Sohankar Esfahani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; blockage; outlet boundary condition; rectangular cylinders; onset of vortex shedding; angle of incidence; incompressible flow; LES; DNS; transition; finite volumes; Reynolds number; numerical simulation; square cylinder;

    Sammanfattning : The subject of flow past slender bluff bodies is of relevance to technical problems associated with energy conservation, structural design and acoustic emissions. The present work is restricted to an important sub-class of slender bluff body flow --- the incompressible flow around a stationary cylinder having a rectangular cross section, the cylinder being exposed to a constant free stream velocity. LÄS MER

  3. 7. Approaching a practice for transient CFD simulations of vortex flow meters

    Författare :Olof Penttinen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laser doppler velocimetry; vortex flow meter model; synthetic inlet boundary condition; circular cylinder in cross-flow; large-eddy simulations;

    Sammanfattning : The usage of Large-Eddy Simulations (LES) in industrial applications makes it possibleto study transient phenomena. The aim of this work is to find a reliable and accurateapproach to transient studies of the internal flow field in a vortex flow meter. LÄS MER

  4. 8. Linear and non-linear dynamics of non-autonomous flows

    Författare :J. Simon Kern; Dan S. Henningson; Ardeshir Hanifi; Peter J. Schmid; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time-dependent flows; linear stability; non-linear dynamics; Floquet analysis; optimally time-dependent modes; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : Fluid flows subject to time-dependent external forces or boundary conditions are ubiquitous in biology and technical applications. Whether one considers birds flying by flapping their wings or the gust response of wind turbines, the flow is non-autonomous. LÄS MER

  5. 9. Slipstream and Flow Structures in the Near Wake of High-Speed Trains

    Författare :Tomas W. Muld; Gunilla Efraimsson; Dan S. Henningson; Chris Baker; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Train transportation is a vital part of the transportation system of today. Asthe speed of the trains increase, the aerodynamic effects become more impor-tant. One aerodynamic effect that is of vital importance for passengers’ andtrack workers’ safety is slipstream, i.e. LÄS MER

  7. 10. Measuring with pressure sensitive paint in time-varying flows

    Författare :Markus Pastuhoff; Henrik Henrk Alfredsson; Ulrich Henne; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pressure sensitive paint; fluid mechanics; internal flow; pulsating flow;

    Sammanfattning : Increasingly tougher legislation on internal combustion engine emissions drives the development towards smaller engines with higher efficiency where an important component is the gas-exchange system and especially the turbocharger. The flow in the gas-exchange system is inherently pulsating and unsteady and the present thesis aims at investigating if and how pressure sensitive paint (PSP) can be used for internal unsteady flows of relevance for engine applications. LÄS MER