Sökning: "separated flows"

Visar resultat 1 - 5 av 41 avhandlingar innehållade orden separated flows.

  1. 1. Large Eddy Simulations of Separated Compressible Flows around Wing Sections

    Författare :Jörgen Held; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; subgrid-scale; shock-boundary layer interaction; wing section; transonic; subsonic; compressible; separated; Large eddy simulation; LES; PVM; Mechanical engineering; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik;

    Sammanfattning : This thesis concerns numerical calculations of compressible separated flows, with and without shocks, around wing sections using Large Eddy Simulations (LES). The considered geometries are the NACA 0012 wing section and the ONERA AT15A wing section. LÄS MER

  3. 2. Optimisation and control of shear flows

    Författare :Antonios Monokrousos; Dan S. Henningson; Laurette Tuckerman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shear flows; flow control; optimal disturbances; Lagrange method; transition to turbulence; non-linear dynamics; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Transition to turbulence and flow control are studied by means of numerical simulations for different simple shear flows. Linear and non-linear optimisation methods using the Lagrange multiplier technique are employed. LÄS MER

  4. 3. Spectral-element simulations of separated turbulent internal flows

    Författare :Johan Ohlsson; Dan Prof Henningson; Jesper Oppelstrup; KTH; []
    Nyckelord :spectral element method; direct numerical simulations DNS ; turbulence; dealiasing; three-dimensional separation; massively parallel simulations;

    Sammanfattning : .... LÄS MER

  5. 4. 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

  7. 5. Models of porous, elastic and rigid materials in moving fluids

    Författare :Ugis Lacis; Shervin Bagheri; Fredrik Lundell; Lakshminarayanan Mahadevan; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid-structure-interaction; flow control; passive appendages; homogenization; poroelastic coatings; separated flows; surface-fluid interface; fluid-struktur-interaktion; flödeskontroll; passiva utväxter; homogenisering; ytbeläggning; separerade strömning; ytbeläggning-strömning gränssnitt; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : Tails, fins, scales, and surface coatings are used by organisms for various tasks, including locomotion. Since millions of years of evolution have passed, we expect that the design of surface structures is optimal for the tasks of the organism. These structures serve as an inspiration in this thesis to identify new mechanisms for flow control. LÄS MER