Sökning: "vortex shedding"

Visar resultat 16 - 20 av 26 avhandlingar innehållade orden vortex shedding.

  1. 16. An experimental study on streamwise streaks in transitional boundary layers

    Författare :Shahab Shahinfar; Jens Fransson; Yury Kachanov; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The present experimental study focuses on two topics, a passive transition-delay method for different types of wave disturbances and the effect of free-stream turbulence characteristics on boundary layer transition over a at plate. In the investigations, hot-wire anemometry was employed and the experiments were performed in a well-controlled wind tunnel facility. LÄS MER

  3. 17. Active Flow Control for Aircrafts and Heavy Vehicles

    Författare :Mohammad El-Alti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trucks; Drag reduction; Bluff-body; Large-eddy Simulation; Wake; Tilt-rotor wing; optimization; Aircrafts; Heavy vehicles; Active and Passive Flow Control; Response surface methodology; Synthetic-jet Actuator;

    Sammanfattning : Bluff-body flows are dominated by large dissipative vortex-shedding wakes with low mean pressure compared to the high pressure on their frontal area. This induced pressure difference is the major contribution to the total aerodynamic drag. LÄS MER

  4. 18. Active Flow Control for Drag Reduction of Heavy Vehicles

    Författare :Mohammad El-Alti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active and Passive Flow Control; Tilt-rotor wing; Large-eddySimulation; Heavy vehicles; optimization; Full-scale road test; Trucks; Bluff-body; Wake; Drag reduction; Aircrafts; Response surface methodology; Synthetic-jet Actuator;

    Sammanfattning : This thesis considers the aerodynamics of trucks. The work focuses on the aerodynamic drag caused by the wake. Bluff-body flows are dominated by large dissipative vortex-shedding wakes with a low mean pressure compared to the high pressure on their frontal area. LÄS MER

  5. 19. Acoustic modeling and testing of exhaust and intake system components

    Författare :Yasser El Nemr; Hans Bodén; Antonio Torregrosa; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Intake and exhaust orifice noise contributes to interior and exterior vehicle noise. The order noise radiated from the orifice of the intake and exhaust systems is caused by the pressure pulses generated by the periodic charging and discharging process and propagates to the open ends of the duct systems. LÄS MER

  7. 20. Utilization of Decomposition Techniques for Analyzing and Characterizing Flows

    Författare :Christian Carlsson; Strömningsteknik; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER