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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. There and back again... An Earth magneto-tale : understanding plasma flows in the magnetotail

    Författare :Alexandre De Spiegeleer; Maria Hamrin; Herbert Gunell; Timo Pitkänen; Colin Forsyth; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma dynamics; Earth magnetosphere; magnetotail; plasma sheet flows; oscillatory flows; burst bulk flows; tailward flows; rymdfysik; Space Physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : On average, the Earth's magnetotail plasma sheet seems to be a calm region of the magnetosphere where the plasma moves slowly towards Earth. However, the plasma sheet actually hosts many phenomena, some of which can affect Earth. LÄS MER

  3. 2. Numerical study of dense particle flows under planar shear

    Författare :Junhao Dong; Beräkningskemi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dense suspension; granular flow; shear thickening; oscillatory flow; rheology; Discrete element method;

    Sammanfattning : In this thesis I conducted numerical simulations to study the flow behavior of dense particle flows composed of hard particles under planar shear using the discrete element method. The simulations were carried out in two dimensional systems, where the particles are modelled as circular discs. The discs are non-Brownian and neutrally buoyant. LÄS MER

  4. 3. A numerical study on orientational arrest and size segregation of dense particle flows using discrete element modeling

    Författare :Zakiyeh Yousefian; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; particle flows; dense suspensions; granular materials;

    Sammanfattning : The thesis focuses on studying dense particle flows, which are either dry or submerged in a Newtonian fluid through two dimensional numerical simulations using the discrete element method (DEM). The First paper deals with dense suspensions in viscous regime under oscillatory planar shear. LÄS MER

  5. 4. Numerical Modelling of Fuel Sprays

    Författare :Christer Bergström; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; Gas turbine.; Temperature fluctuations. Diesel engine; Counter rotating Vortex Pair; CVP; Large Eddy Simulation; Droplet Evaporation; Turbulent flows; LES; Spray; Modelling; Break-up; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; bränslen; sprängämnen;

    Sammanfattning : The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction beween the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. LÄS MER

  7. 5. Hydrodynamics and heat convection in channels with vibrating walls

    Författare :Fredrik Carlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this work a combined analytical and numerical study of the non-linear effects of transverse wall vibrations on fluid flows are presented. Streaming motions and their effect on heat and mass transfer are investigated for a viscous fluid confined in an infinite channel with flexible walls. LÄS MER