Sökning: "vortex model"

Visar resultat 1 - 5 av 102 avhandlingar innehållade orden vortex model.

  1. 1. Fluid Mechanics of Vertical Axis Turbines Simulations and Model Development

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Anders Goude; Uppsala universitet.; [2012]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind power; Marine current power; Vertical axis turbine; Wind farm; Channel flow; Simulations; Vortex model; Streamtube model; Control system; Graphics processing unit; CUDA; Fast multipole method; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Two computationally fast fluid mechanical models for vertical axis turbines are the streamtube and the vortex model. The streamtube model is the fastest, allowing three-dimensional modeling of the turbine, but lacks a proper time-dependent description of the flow through the turbine. LÄS MER

  2. 2. Vortex fluctuations in superconductors

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Peter Olsson; Umeå universitet.; [1992]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Superconductor; Two dimensions; vortex; coulomb gas; XY model; Kosterlitz-Thouless transition; high-Tc.;

    Sammanfattning : The vortex fluctuations have proved to be responsible for the onset of dissipation in thin type-II superconducting Aims. There is also growing evidence that dissipation in high- temperature superconductors exhibits the same kind of two-dimensional (2D) behavior. LÄS MER

  3. 3. Wind turbine wakes controland vortex shedding

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Davide Medici; KTH.; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Energy; Power Optimisation; Active Control; Yaw; Vortex; TECHNOLOGY Engineering mechanics Mechanical and thermal engineering Mechanical energy engineering; TEKNIKVETENSKAP Teknisk mekanik Mekanisk och termisk energiteknik Mekanisk energiteknik;

    Sammanfattning : Wind tunnel studies of the wake behind a model wind turbine have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry as well as particle image velocimetry (PIV) have been used to map the flow field. LÄS MER

  4. 4. Analytical vortex solutions to Navier-Stokes equation

    Detta är en avhandling från Växjö : Växjö University Press

    Författare :Henrik Tryggeson; Växjö universitet.; [2007]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; conical vortex; Navier-Stokes equation; analytical solution; 2-D vortices; turbulence; vortex ring; stretched vortex; coherent structures; TECHNOLOGY Engineering mechanics Fluid mechanics; TEKNIKVETENSKAP Teknisk mekanik Strömningsmekanik;

    Sammanfattning : Fluid dynamics considers the physics of liquids and gases. This is a branch of classical physics and is totally based on Newton's laws of motion. Nevertheless, the equation of fluid motion, Navier-Stokes equation, becomes very complicated to solve even for very simple configurations. LÄS MER

  5. 5. Vortex generator modeling and its application to optimal control of airflow in inlet

    Detta är en avhandling från Stockholm : KTH

    Författare :Adam Jirásek; KTH.; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vortex generator; vortex generator model; flow control; design and optimization; DOE; CFD; UAV; inlet; S-duct; pressure distortion; pressure recovery; TECHNOLOGY Engineering mechanics Vehicle engineering; TEKNIKVETENSKAP Teknisk mekanik Farkostteknik;

    Sammanfattning : This dissertation deals with the development of the vortex generator model and its use for the optimization study of vortex generator flow control in high-offset-ed inlets. In the first part, the overview of use of vortex generators and their mechanism is outlined. LÄS MER