Sökning: "flux tube simulations"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden flux tube simulations.

  1. 1. Transport Barriers in Plasmas and Fluids

    Författare :Robert Moestam; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DNS; transport barriers; Zonal flows; L-H mode transition; turbulence simulations; drift waves; flux tube simulations; nonlinear instabilities; linear instabilities;

    Sammanfattning : In the present work different mechanisms for generation and suppression of turbulence are studied. The suppression of nonlinearly generated turbulence stabilized by temperature boundary conditions as well as turbulence generated by linear instabilities and suppressed by nonlinearly generated secondary flows are treated. LÄS MER

  3. 2. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

    Författare :Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
    Nyckelord :Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. LÄS MER

  4. 3. Nonazeotropic mixtures as working fluids in large heat pumps - Heat transfer in a falling film evaporator and system simulations

    Författare :Karin Munch; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The thesis is divided into two main parts, the first onedealing with heat transfer in the evaporator and the secondone dealing with simulations of the whole heat pump cyclewith nonazeotropic mixtures. One of the aims with the heat transfer studies was to investigate if the additional mass transfer resistance, introduced when mixtures are used, can be reduced in a thin falling film with high turbulence compared with corresponding one for a horizontal tube. LÄS MER

  5. 4. Imaging spectropolarimetry of solar active regions

    Författare :Gautam Narayan; Göran Scharmer; Rolf Schlichenmaier; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; Spectropolarimetry; Solar magnetic fields; Sunspots; Plages; Solar physics; Solfysik; Astronomy; astronomi;

    Sammanfattning : Solar magnetic fields span a wide range of spatial scales from sunspots and plages to magnetic bright points. A clear understanding of the physical processes underlying the evolution of these magnetic features requires high-resolution spectropolarimetric observations of solar active regions and comparisons with synthetic data from simulations. LÄS MER

  7. 5. Coil Design and Related Studies for the Fusion-Fission Reactor Concept SFLM Hybrid

    Författare :Anders Hagnestål; Olov Ågren; Vladimir Moiseenko; Ladislav Bardos; Jan Scheffel; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fusion; Fission; Hybrid reactor; Actinides; Mirror Machine; Quadrupolar mirror; Coils; Fysik; Physics;

    Sammanfattning : A fusion-fission (hybrid) reactor is a combination of a fusion device and a subcritical fission reactor, where the fusion device acts as a neutron source and the power is mainly produced in the fission core. Hybrid reactors may be suitable for transmutation of transuranic isotopes in the spent nuclear fuel, due to the safety margin on criticality imposed by the subcritical fission core. LÄS MER