Sökning: "fluid and plasma"

Visar resultat 1 - 5 av 323 avhandlingar innehållade orden fluid and plasma.

  1. 1. Drift-Type Waves in Rotating Tokamak Plasma

    Detta är en avhandling från Uppsala : Institutionen för astronomi och rymdfysik

    Författare :Elina Asp; Vladimir Pavlenko; Hans Nordman; [2003]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; fusion; plasma; tokamak; rotation; drift; ship; ITG; TE; Landau; Te Ti; hot-electron; confinement; stiffness; Weiland; Rymd- och plasmafysik; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik; Space and Plasma Physics; rymd- och plasmafysik;

    Sammanfattning : The concept of energy production through the fusion of two light nuclei has been studied since the 1950’s. One of the major problems that fusion scientists have encountered is the confinement of the hot ionised gas, i.e. the plasma, in which the fusion process takes place. LÄS MER

  2. 2. Gravitational perturbations in plasmas and cosmology

    Detta är en avhandling från Umeå : Institutionen för Fysik

    Författare :Mats Forsberg; Gert Brodin; Michael Bradley; Christopher Clarkson; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; general relativity; cosmology; gravitational waves; plasma; electromagnetic waves; nonlinear waves; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Plasma physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Plasmafysik; NATURAL SCIENCES Physics Other physics Theory of relativity; gravitation; NATURVETENSKAP Fysik Övrig fysik Relativitetsteori; gravitation; NATURAL SCIENCES Physics Astronomy and astrophysics Cosmology; NATURVETENSKAP Fysik Astronomi och astrofysik Kosmologi; teoretisk fysik; Theoretical Physics;

    Sammanfattning : Gravitational perturbations can be in the form of scalars, vectors or tensors. This thesis focuses on the evolution of scalar perturbations in cosmology, and interactions between tensor perturbations, in the form of gravitational waves, and plasma waves. LÄS MER

  3. 3. Plasma Arc Welding Simulation with OpenFOAM

    Detta är en avhandling från Umeå : Institutionen för Fysik

    Författare :Margarita Sass-Tisovskaya; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A simulation tool that is valid within the field of tandem arc welding(unsteady, three dimensional thermal plasma flow) has been developed,based on the open source CFD package OpenFOAM. The validation of the electromagnetic part of the solver has been done separately using a problem with a known solution. LÄS MER

  4. 4. Modelling of cathode-plasma interaction in short high-intensity electric arc - Application to Gas Tungsten Arc Welding

    Detta är en avhandling från Umeå : Institutionen för Fysik

    Författare :Alireza Javidi-Shirvan; [2016]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; sheath; Gas Tungsten Arc simulation; doped refractory cathode; Knudsen layer; electric arc discharge; OpenFOAM.; pre-sheath; arc-cathode coupling;

    Sammanfattning : In arc welding the quality of the weld is strongly influenced by the thermal history of the workpiece which is itself governed by the electric arc heat source. The models for predicting weld properties thus need a good evaluation of the distribution of the heat input from the arc to the workpiece. LÄS MER

  5. 5. Gyrokinetic simulations of turbulent transport in tokamak plasmas

    Detta är en avhandling från Umeå : Institutionen för Fysik

    Författare :Andreas Skyman; [2014]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; fusion; TEM; ITG; tokamaks; e-science; Joint European Torus; turbulence; gyrokinetics; plasma physics; impurity transport;

    Sammanfattning : With the enormous growth of high performance computing (HPC) over the last few decades, plasma physicists have gained access to a valuable instrument for investigating turbulent plasma behaviour. In this thesis, these tools are utilised for the study of particle transport in fusion devices of the tokamak variety. LÄS MER