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Visar resultat 1 - 5 av 51 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Power and Wake Dynamics of Hawkmoth Flight

    Författare :Kajsa Warfvinge; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Insect flight; Aerodynamics; Wind tunnel; Particle Image Velocimetry PIV .; tomo-PIV; Power; Manduca sexta; Macroglossum stellatarum; Hawkmoth;

    Sammanfattning : Aerodynamic theory states that the power required to fly is related to flight speed with a ∪-shaped curve. This has been shown in vertebrates, but insects have been proposed to have a flat, or J-shaped power curve. LÄS MER

  3. 2. In the wake of a bird - Quantifying aerodynamic performance of avian flight

    Författare :Marco Klein Heerenbrink; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; animal flight; flight performance; gliding; powered flight; wing morphology; aerodynamics; biomechanics; birds; jackdaw; Corvus monedula; wind tunnel; PIV;

    Sammanfattning : Flight is an expensive form of locomotion, but also offers the ability to travel great distances at relatively low cost. Birds have developed various adaptations for optimizing flight performance. The main aim of this thesis is to identify how morphological variables in birds affect aerodynamic drag and flight performance. LÄS MER

  4. 3. Always on the wing - Fluid dynamics, flight performance and flight behavior of common swifts

    Författare :Per Henningsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Apus apus; aerodynamics; animal flight; kinematics; vortex wake; digital particle image velocimetry; DPIV; common swift; tracking radar; wind tunnel; migration; roosting flight;

    Sammanfattning : The aerodynamics and kinematics behind the flight of animals are relatively unknown. Although animal flight has been studied for several hundreds of years, it is only in recent time that we have the technical abilities to study the mechanistic basis of animal flight. LÄS MER

  5. 4. Power Extraction in Military Aircraft

    Författare :Daniel Rosell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; engine performance; mixed flow; turbofan engine; low bypass ratio; Fighter aircraft performance; power extraction;

    Sammanfattning : Military aircraft require more and more power. Pneumatic and hydraulic systems are being replaced by electrical equipment and new, power consuming equipmentis introduced in the aircraft. Increased power extraction brings new challenges for the aircraft jet engine, both in terms of operability and with regards to engine performance. LÄS MER

  7. 5. Feathers by day, membranes by night - Aerodynamic performance in bird and bat flight

    Författare :Florian Muijres; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; animal flight; aerodynamics; vortex wake; actuator disk; flight performance; span efficiency; bird; bat; wind tunnel; PIV; Pied Flycatcher; Glossophaga soricina; Leptonycteris yerbabuenae;

    Sammanfattning : The efficiency and performance of a flying animal is directly related to the aerodynamics around its body and flapping wings. Here, I have developed methods for quantifying the wake dynamics around a flying animal. The results are used to estimate the aerodynamic performance of flapping flight. LÄS MER