Sökning: "Magnetohydrodynamics"

Hittade 5 uppsatser innehållade ordet Magnetohydrodynamics.

  1. 1. SECOND-ORDER DIVERGENCE-FREE FEM FOR MAGNETOHYDRODYNAMICS USING LAGRANGE POLYNOMIALS

    Kandidat-uppsats, Uppsala universitet/Institutionen för informationsteknologi

    Författare :Erik Björklund; Peter Mårtensson; Noah Waltman; [2023]
    Nyckelord :;

    Sammanfattning : AbstractMaxwell’s laws state that the divergence of a magnetic field always remains zero. In thecontinuous setting this is true for the magnetohydrodynamics equations. However, in thediscrete setting, the solution does not always remain divergence-free. LÄS MER

  3. 2. Concept investigation into Metal Plasma Source for High Powered Space Applications

    Master-uppsats, Luleå tekniska universitet/Rymdteknik

    Författare :Ludvig Borg; [2023]
    Nyckelord :High-powered; Electric Propulsion; Vacuum Arc Thruster; VASIMR; Metal Plasma; Magnetohydrodynamics; COMSOL Multiphysics;

    Sammanfattning : This thesis explores the potential of utilizing metal-based plasma sources as a sustainable solution for high-powered electric propulsion and its implications for future interplanetary travel. Focusing on the Vacuum Arc Thruster and the Variable Specific Impulse Magnetoplasma Rocket engine, the study encompasses numerical simulations, analytical comparisons, and performance analyses to assess the feasibility of metal plasma fuels in space missions. LÄS MER

  4. 3. Electron heating in collisionless shocks observed by the MMS spacecraft

    Master-uppsats, Luleå tekniska universitet/Rymdteknik

    Författare :Martin Svensson; [2018]
    Nyckelord :shocks; MMS; electron; heating; gradient; quasi-perpendicular; scaling; plasma; space;

    Sammanfattning : Shock waves are ubiquitous in space and astrophysics. Shocks transform directed particle flow energy into thermal energy. As the major part of space is a collisionless medium, shocks in space physics arises through wave-particle interactions with the magnetic field as the main contributor.The heating processes are scale dependent. LÄS MER

  5. 4. Inference of chromospheric magnetic fields with the Ca II 8542 line

    Master-uppsats, Uppsala universitet/Teoretisk astrofysik

    Författare :Filip Jennerholm Hammar; [2014]
    Nyckelord :Sun: chromosphere; Sun: magnetic topology; polarization; weak field approximation;

    Sammanfattning : Several techniques exist for retrieving and studying information about the properties of the Solar atmosphere from the polarization state of spectral lines. These are commonly called spectral diagnostics. LÄS MER

  7. 5. Hydrodynamic simulations with a radiative surface

    Master-uppsats, Institutionen för astronomi

    Författare :Atefeh Barekat; [2013]
    Nyckelord :The Sun; Magnetohydrodynamics; radiative transfer;

    Sammanfattning : We solve the equations of radiation hydrodynamics to compute the time evolution toward one-dimensional equilibrium solutions using ageneralized Kramers opacity, κ=κ0 ρa Tb, with adjustable prefactor κ0 and exponents a and b on density ρ and temperature T, respectively. We choose our initial conditions to be isothermal and find that the early time evolution away from the isothermal state is fastest near the height where the optical depth is unity, and is slower both above and below it. LÄS MER