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

  1. 1. Stability analysis of channel flow laden with small particles

    Författare :Joy Klinkenberg; Luca Brandt; Cristian Marchioli; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transition; modal analysis; non-modal analysis; Direct Numerical Simulations; multi-phase flow; heavy particles; light particles; particle-laden;

    Sammanfattning : This thesis deals with the stability of particle laden flows. Both modal and non-modal linear analyses have been performed on two-way coupled particleladen flows, where particles are considered spherical, solid and either heavy or light. When heavy particles are considered, only Stokes drag is used as interaction term. LÄS MER

  3. 2. Global stability analysis of complex fluids

    Författare :Iman Lashgari; Luca Brandt; Francois Gallaire; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-Newtonian flow; Carreau model; Oldroyd-B model; FENE-P model; modal analysis; nonmodal analysis; sensitivity analysis;

    Sammanfattning : The main focus of this work is on the non-Newtonian effects on the inertial instabilities in shear flows. Both inelastic (Carreau) and elastic models (Oldroyd-B and FENE-P) have been employed to examine the main features of the non-Newtonian fluids; shear-thinning, shear-thickening and elasticity. LÄS MER

  4. 3. Transition in Particle-laden Flows

    Författare :Joy Klinkenberg; Luca Brandt; Shuisheng He; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transition; modal analysis; non-modal analysis; multi-phase flow; particle-laden; heavy particles; light particles;

    Sammanfattning : This thesis presents the study of laminar to turbulent transition of particle laden flows. When a flow becomes turbulent, the drag increases one order of magnitude compared to a laminar flow, therefore, much research is devoted to understand and influence the transition. LÄS MER

  5. 4. Stability analysis and inertial regimes in complex  flows

    Författare :Iman Lashgari; Luca Brandt; Anke Lindner; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-Newtonian flow; global stability analysis; inertial suspensions; particle dynamics;

    Sammanfattning : In this work we rst study the non-Newtonian effects on the inertial instabilities in shear flows and second the inertial suspensions of finite size rigid particles by means of numerical simulations.In the first part, both inelastic (Carreau) and elastic models (Oldroyd-B and FENE-P) have been employed to examine the main features of the non-Newtonian fluids in several congurations; flow past a circular cylinder, in a lid-driven cavity and in a channel. LÄS MER

  7. 5. Stability analysis and transition prediction of wall-bounded flows

    Författare :Ori Levin; KTH; []
    Nyckelord :Boundary layer; wall jet; algebraic growth; exponential growth; lift-up effect; streamwise streaks; Tollmien-Schlichting waves; free-stream turbulence; roughness element; transition prediction; Parabolized Stability Equations; Direct Numerical S;

    Sammanfattning : Disturbances introduced in wall-bounded .ows can grow andlead to transition from laminar to turbulent .ow. In order toreduce losses or enhance mixing in energy systems, afundamental understanding of the . LÄS MER