Sökning: "vortex"

Visar resultat 6 - 10 av 257 avhandlingar innehållade ordet vortex.

  1. 6. Resistive studies of vortices and fluctuations in single crystal YBa2Cu3O7-

    Författare :Therese Björnängen; KTH; []
    Nyckelord :condensed matter physics; high temperature superconductors; YB2Cu3O7-d; untwinned YBCO; oxygen deficiency; superconducting fluctuations; magnetoconductivity; in-plane anisotropy; vortex liquid; vortex solid; vortex correlation;

    Sammanfattning : High-temperature superconductors have been intensely studiedsince the discovery, almost 20 years ago. Their layeredstructure, extreme type-II behavior, large anisotropy, andstrong fluctuations have led to a large number of new andinteresting problems. LÄS MER

  3. 7. Structures, Properties and Dynamics of Turbulent Vortices

    Författare :Farideh Ghasempour; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES.; Vortex structure; Turbulence; Vortex properties; Vortex dynamics;

    Sammanfattning : The development of models for several phenomena that occur in turbulent single- and multi-phase flows requires improved descriptions and quantifications of turbulent vortices. In many engineering applications, the time scale of these phenomena is equal to or smaller than the lifetime of turbulent vortices; consequently, they are not adequately described by using average turbulence properties. LÄS MER

  4. 8. Adaptive Mesh Refinement and Simulations of Unsteady Delta-Wing Aerodynamics

    Författare :Yann Le Moigne; KTH; []
    Nyckelord :delta wing; high angle of attack; vortex; pitching; mesh refinement; UCAV; vortex sensor; tensor ofvelocity gradients;

    Sammanfattning : This thesis deals with Computational Fluid Dynamics (CFD)simulations of the flow around delta wings at high angles ofattack. These triangular wings, mainly used in militaryaircraft designs, experience the formation of two vortices ontheir lee-side at large angles of attack. LÄS MER

  5. 9. Resonant switching and vortex dynamics in spin-flop bi-layers

    Författare :Sergiy Cherepov; Vladislav Korenivski; Thomas Silva; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-dynamics; MRAM; vortex; switching; Condensed matter physics; Kondenserade materiens fysik; Magnetism; Magnetism; Mesoscopic physics; Mesoskopisk fysik;

    Sammanfattning : This thesis is a study of the static and dynamic behavior of the magne-tization in spin-flop bi-layers, which consist of two soft ferromagnetic layerscoupled by dipolar forces through a thin nonmagnetic spacer. The focus ofthe work is three fold: collective spin dynamics in the anti-parallel groundstate; resonant switching in the presence of thermal agitation; and static anddynamic behavior of the system in the vortex-pair state, with a particularemphasis on the interlayer core-core interaction. LÄS MER

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

    Författare :Adam Jirásek; Arthur Rizzi; John W Slater; KTH; []
    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; Vehicle engineering; 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