Search for dissertations about: "self-sustained turbulence"

Found 3 swedish dissertations containing the words self-sustained turbulence.

  2. 1. Experimental study on turbulent boundary-layer flows with wall transpiration

    Author : Marco Ferro; Jens Fransson; Bengt Fallenius; Joseph Klewicki; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent boundary layer; boundary-layer suction; boundary-layer blowing; wall-bounded turbulent flows; self-sustained turbulence; Engineering Mechanics; Teknisk mekanik;

    Abstract : Wall transpiration, in the form of wall-normal suction or blowing through a permeable wall, is a relatively simple and effective technique to control the behaviour of a boundary layer. For its potential applications for laminar-turbulent transition and separation delay (suction) or for turbulent drag reduction and thermal protection (blowing), wall transpiration has over the past decades been the topic of a significant amount of studies. READ MORE

  4. 2. Analysis and control of transitional shear flows using global modes

    Author : Shervin Bagheri; Dan Henningson; Alessandro Bottaro; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; flow control; hydrodynamic stability; global modes; jet in crossflow; flat-plate boundary layer; laminar-turbulent transition; Arnoldi method; Koopman modes; balanced truncation; direct numerical simulations.; Fluid mechanics; Strömningsmekanik;

    Abstract : In this thesis direct numerical simulations are used to investigate two phenomenain shear flows: laminar-turbulent transition over a flat plate and periodicvortex shedding induced by a jet in cross flow. The emphasis is on understanding and controlling the flow dynamics using tools from dynamical systems and control theory. READ MORE

  5. 3. Improved Flutter Prediction for Turbomachinery Blades with Tip Clearance Flows

    Author : Tianrui Sun; Andrew R. Martin; Paul Petrie-Repar; Mihai Mihaescu; KTH; []
    Keywords : Steam turbine; Flutter; Aeroelastic stability; Tip clearance flow; Detached-Eddy Simulation; Energiteknik; Energy Technology;

    Abstract : Recent design trends in steam turbines strive for high aerodynamic loading and high aspect ratio to meet the demand of higher efficiency. These design trends together with the low structural frequency in last stage steam turbines increase the susceptibility of the turbine blades to flutter. READ MORE