Sökning: "plasma turbulence"

Visar resultat 11 - 15 av 56 avhandlingar innehållade orden plasma turbulence.

  1. 11. Turbulence and scalar flux modelling applied to separated flows

    Författare :Johan Gullman-Strand; Arne V. Johansson; Suad Jakirlic; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; fluid physics; plasma physics; applied mechanics; aerospace; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : The turbulen flow in an asymmetric diffuser has been en studied by the means of Reynold average Navier-Stokes equations with both differential and explict algebraic expressions to model the Reynolds stress tensor. Modifications to the differential stress model have been derived, using the inverse turbulence timescale to obtain the dissipation of turbuence kinetic energy. LÄS MER

  3. 12. Solitary waves and enhanced incoherent scatter ion lines

    Författare :Jonas Ekeberg; Lars Eliasson; Kristof Stasiewicz; Jan Trulsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasma waves and instabilities; nonlinear phenomena; solitons and solitary waves; ionosphere; Sun: corona; incoherent scatter radar; MHD; plasmavågor och instabiliteter; ickelinjära fenomen; solitoner och solitära vågor; jonosfär; solen: korona; inkoherent spridningsradar; MHD; Geocosmophysics and plasma physics; Geokosmofysik och plasmafysik; Space physics; Rymdfysik; Plasma physics; Plasmafysik; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos; fysik; Physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : This thesis addresses solitary waves and their significance for auroral particle acceleration, coronal heating and incoherent scatter radar spectra. Solitary waves are formed due to a balance of nonlinear and dispersive effects. LÄS MER

  4. 13. Energy Conversion and Particle Acceleration at Turbulent Plasma Jet Fronts

    Författare :Louis Richard; Yuri V. Khotyaintsev; Daniel B. Graham; Andris Vaivads; Emiliya Yordanova; Vassilis Angelopoulos; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma jets; Magnetic reconnection; Particle acceleration; Magnetosphere; Magnetospheric Multiscale; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : High-speed plasma flows (jets) are ubiquitous phenomena in the visible Universe. When the fast plasma flow encounters the ambient plasma at rest, it forms a front where its kinetic energy is dissipated. At the jet front, charged particles gain energy from the electromagnetic fields through heating and acceleration. LÄS MER

  5. 14. Time Spectral Methods - Towards Plasma Turbulence Modelling

    Författare :Kristoffer Lindvall; Jan Scheffel; Carl Sovinec; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fusion; Turbulence; Micro-instabilities; Time-spectral; Navier-Stokes; MHD; Weiland model; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Energy comes in two forms; potential energy and kinetic energy. Energyis stored as potential energy and released in the form of kinetic energy. This process of storage and release is the basic strategy of all energy alternatives in use today. This applies to solar, wind, fossil fuels, and the list goes on. LÄS MER

  7. 15. Magnetic Reconnection in Space Plasmas : Cluster Spacecraft Observations

    Författare :Alessandro Retinò; Mats André; Andris Vaivads; Bengt U. Ö. Sonnerup; Uppsala universitet; []
    Nyckelord :Space and plasma physics; space physics; plasma astrophysics; plasma physics; transport processes; boundary layers; magnetic reconnection; turbulence; particle acceleration; solar system; magnetospheres; Rymd- och plasmafysik;

    Sammanfattning : Magnetic reconnection is a universal process occurring at boundaries between magnetized plasmas, where changes in the topology of the magnetic field lead to the transport of charged particles across the boundaries and to the conversion of electromagnetic energy into kinetic and thermal energy of the particles. Reconnection occurs in laboratory plasmas, in solar system plasmas and it is considered to play a key role in many other space environments such as magnetized stars and accretion disks around stars and planets under formation. LÄS MER