Search for dissertations about: "vortex breakdown"

Showing result 21 - 25 of 34 swedish dissertations containing the words vortex breakdown.

  2. 21. Unsteady Numerical Simulations of Flow around Heavy Vehicles, Trains and Passenger Cars

    Author : Jan Östh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large Eddy Simulation; fluid dynamics; bluff body flows; flow structures; vehicle aerodynamics; flow control; flow physics; truck aerodynamics; train aerodynamics; car aerodynamics;

    Abstract : In this thesis several simulations have been carried out aimed at improving the knowledgeof vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Four flows around different simplified vehicles have been considered. READ MORE

  4. 22. Studies of Gas Turbines Combustion Chambers: Use of New Fuels and Development of New Tools

    Author : Christophe Duwig; Strömningsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Termisk teknik; termodynamik; applied thermodynamics; Thermal engineering; Flamelets; LES; CFD; Gas Turbine; Combustion;

    Abstract : The growing world electricity demand and environmental concerns pushes toward new technology for electricity production. Within the thermal processes for electricity production, two axis of research are being developed to meet the needs of the industry, namely using renewable fuels and new generation burners technology. READ MORE

  5. 23. Linear and non-linear dynamics of non-autonomous flows

    Author : J. Simon Kern; Dan S. Henningson; Ardeshir Hanifi; Peter J. Schmid; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time-dependent flows; linear stability; non-linear dynamics; Floquet analysis; optimally time-dependent modes; Teknisk mekanik; Engineering Mechanics;

    Abstract : Fluid flows subject to time-dependent external forces or boundary conditions are ubiquitous in biology and technical applications. Whether one considers birds flying by flapping their wings or the gust response of wind turbines, the flow is non-autonomous. READ MORE

  6. 24. Utilization of Decomposition Techniques for Analyzing and Characterizing Flows

    Author : Christian Carlsson; Strömningsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Decomposition techniques; Proper orthogonal decomposition; Dynamic mode decomposition; Extended dynamic mode decomposition; Swirl switching; Swirling flow; Low swirl burner; Fluid-structure interaction;

    Abstract : This thesis presents the utilization of two different decomposition techniques, proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), for enhanced understanding of flow structures and their stability. The advantages of these techniques are shown for a range of flow situations, most of which are turbulent. READ MORE

  7. 25. CFD driven optimization of hydraulic turbine draft tubes using surrogate models

    Author : Daniel Marjavaara; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Abstract : The efficiency of a hydraulic reaction turbine is significantly affected by the performance of its draft tube. The shape and velocity distribution at the inlet are, in next turn, two main factors that affects the performance of the draft tube. READ MORE