Search for dissertations about: "fluid and plasma"

Showing result 1 - 5 of 367 swedish dissertations containing the words fluid and plasma.

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

    Author : Alireza Javidi Shirvan; Isabelle Choquet; Håkan Nilsson; Armelle Vardelle; Högskolan Väst; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Electric arc discharge; sheath; pre-sheath; Knudsen layer; doped refractory cathode; arc-cathode coupling; Gas Tungsten Arc simulation; OpenFOAM.; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Abstract : 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 thearc to the workpiece. READ MORE

  4. 2. Gravitational perturbations in plasmas and cosmology

    Author : Mats Forsberg; Gert Brodin; Michael Bradley; Christopher Clarkson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; general relativity; cosmology; gravitational waves; plasma; electromagnetic waves; nonlinear waves; Plasma physics; Plasmafysik; Theory of relativity; gravitation; Relativitetsteori; gravitation; Cosmology; Kosmologi; teoretisk fysik; Theoretical Physics;

    Abstract : 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. READ MORE

  5. 3. Plasma Arc Welding Simulation with OpenFOAM

    Author : Margarita Sass-Tisovskaya; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : 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. READ MORE

  6. 4. Drift-Type Waves in Rotating Tokamak Plasma

    Author : Elina Asp; Vladimir Pavlenko; Hans Nordman; Uppsala universitet; []
    Keywords : 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; Space physics; Rymdfysik; Space and Plasma Physics; rymd- och plasmafysik;

    Abstract : 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. READ MORE

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

    Author : Andreas Skyman; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE