Sökning: "transition plane"

Visar resultat 1 - 5 av 121 avhandlingar innehållade orden transition plane.

  1. 1. Spectral-element simulations of turbulent wall-bounded flows including transition and separation

    Författare :Johan Malm; Dan Henningson; Philipp Schlatter; Suad Jakirlic; KTH; []
    Nyckelord :spectral-element method; direct numerical simulation DNS ; large-eddy simulation LES ; turbulence; transition; over-integration; three-dimensional separation; massively parallel simulations; proper orthogonal decomposition POD ; Koopman modes; vorticity stretching; coherence; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ;

    Sammanfattning : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. LÄS MER

  3. 2. 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

  4. 3. Hydrodynamics of plane liquid jets aimed at applications in paper manufacturing

    Författare :Daniel Söderberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; liquid jet; transition; break-up; stability; wavelet; free surface; waves; streamwise streaks; fibre suspension; headbox; forming; shadowgraph; hot-film; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Process industries are in general depending, in one way or the other, on fluid mechanics.Specifically, paper manufacturing, which probably is the dominant processindustry in Sweden, is depending on the flow of cellulose fibres suspended in water. LÄS MER

  5. 4. Stability and transition of three-dimensional boundary layers

    Författare :Seyed Mohammad Hosseini; Ardeshir Hanifi; Vassilios Theofilis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; stability; optimal growth; three-dimensional boundary layers; crossflow instability; roughness control; freestream turbulence; secondary instability;

    Sammanfattning : A focus has been put on the stability characteristics of different flow types existing on air vehicles. Flow passing over wings and different junctions on an aircraft face numerous local features, ranging from different pressure gradients, to interacting boundary layers. LÄS MER

  7. 5. Direct numerical simulation of turbulent flow in plane and cylindrical geometries

    Författare :Jukka Komminaho; KTH; []
    Nyckelord :turbulence; plane Couette flow; pipe flow; laminar-turbulent transition; direct numerical simulation; spectral methods;

    Sammanfattning : This thesis deals with numerical simulation of turbulentflows in geometrically simple cases. Both plane and cylindricalgeometries are used. The simplicity of the geometry allows theuse of spectral methods which yield a very high accuracy usingrelatively few grid points. A spectral method for planegeometries is implemented on a parallel computer. LÄS MER