Search for dissertations about: "vortex breakdown"

Showing result 16 - 20 of 34 swedish dissertations containing the words vortex breakdown.

  2. 16. On the Aerodynamic Design of the Boxprop

    Author : Alexandre Capitao Patrao; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Open Rotors; Wake Analysis Method; Propeller Design; Propellers; CROR; Optimization; Tip vortex; Propfans;

    Abstract : Economic factors and environmental awareness are driving the evolution of aircraft engines towards increasingly lower fuel consumption and emissions. The Counter-Rotating Open Rotor (CROR) is actively being researched around the world, promising a significantly increased propulsion efficiency relative to existing turbofans by employing two, unducted, counter-rotating propeller blade rows, thereby increasing the bypass ratio of the engine and decreasing nacelle drag. READ MORE

  4. 17. Realistic simulations of delta wing aerodynamics using novel CFD methods

    Author : Stefan Görtz; Arthur Rizzi; Miguel Visbal; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; CFD; aerodynamics; flow physics; steady; unsteady; delta wing; vortical flow; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Abstract : The overall goal of the research presented in this thesis is to extend the physical understanding of the unsteady external aerodynamics associated with highly maneuverable delta-wing aircraft by using and developing novel, more efficient computational fluid dynamics (CFD) tools. More specific, the main purpose is to simulate and better understand the basic fluid phenomena, such as vortex breakdown, that limit the performance of delta-wing aircraft. READ MORE

  5. 18. Numerical study on instability and interaction of wind turbine wakes

    Author : Sasan Sarmast; Dan. S. Henningson; Per-Åge Krogstad; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind turbine wakes; Stability; interaction; POD; DMD; Teknisk mekanik; Engineering Mechanics;

    Abstract : Numerical simulations of the Navier-Stokes equations are conducted to achieve a better understanding of the behavior of wakes generated by the wind turbines. The simulations are performed by combining the in-house developed code EllipSys3D with the actuator line technique. READ MORE

  6. 19. Northern Hemispheric Cold Spells and their Tropospheric-Stratospheric Link

    Author : Kathrin Finke; Abdel Hannachi; Jörg Gumbel; Alexey Karpechko; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

    Abstract : Cold spells have severe consequences for society. They require early warnings for elaborate mitigation strategies on sub-seasonal to seasonal time-scales. READ MORE

  7. 20. Unsteady Numerical Simulations and Reduced-Order Modelling of Flows around Vehicles

    Author : Jan Östh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduced-Order Modelling; Numerical Simulations; Large Eddy Simulation; Vehicle Aerodynamics;

    Abstract : In this thesis several simulations have been carried out aimed at improving the knowledge of vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Five flows around different simplified vehicle models have been considered in five appended publications. READ MORE