Analyse des Schlagfluges mit verformten Flügeln

von Nadine Buchmann

104 Seiten, Taschenbuch

Kurzbeschreibung des Verlags

Abstract
The present thesis covers the design of a birdlike aerofoil and three-dimensional wing. The ob-
jecitve of this work is to transfer two-dimensional aerofoil kinematics to this three-dimensional
wing retaining values of thrust and propulsive efficiency and to give a prospect of the efficiency
of realistic and natural wing kinematics. Furthermore the effect of variying wing motion on the
generation of thrust and propulsive efficiency is studied using computational fluid dynamics and
grid deforming technique.
Therefore well analysed two-dimensional airfoil kinematics are extended to three-dimensional
flapping wings. Three-dimensional effects decrease the effective angle of attack and result in re-
duced values of thrust and propulsive efficiency. The induced angles of attack on finite wings
are identified with a stationary vortex system method and taken into to account by defining
the wing flapping motion. The results in thrust and propulsive efficiency of the wing’s design
section of moderate motion deflection cases with high propulsive efficiency show good agreement
compared with equivalent two-dimensional values. For cases with larger amount of deflections
the three-dimensional simulation did come close to the two-dimensional results. This is due to
large tip vortices and a flow separation on the pressure side during upstroke.
Analysis of wing motion with large deviations demonstrate limitations of the stationary vortex
system to identify the induced angles of attack. This limits illustrate the need to consider un-
steady effects into the identification of induced angles of attack using non-linear methods with
high order polynomials.
The results of this work demonstrate the flapping motion’s sensitivity to parameter changes.

• Reihe: NFL-Forschungsberichte
• ISBN: 9783928628945
• Erscheinungsdatum: 01.01.2017
• Genre: Technik/Luftfahrttechnik, Raumfahrttechnik
• Verlag: Technische Uni Braunschweig NFL