Abstract Multi-element wing tips based on bird wings appear attractive in soaring flight, where a minimal sink velocity is the design goal. The present study aims to reproduce flight observed from white storks (ciconia ciconia) biomimetic computational model order visualize and investigate flow around through tip cascade. RANS hybrid RANS–LES computations have been performed allowing access all...

Research in the field of Flapping Wing Micro Air Vehicle (FMAV) is an ongoing quest to master the natural flyers by mechanical means. The field is characterized by unsteady aerodynamics, whose knowledge is still developing. Birds and insects have different methods of producing lift and thrust for hovering and forward flight. Most birds, however, cannot hover. Wing tips of birds follow simple pa...

In this article, numerical and experimental analyzes were made by adding winglet endless blade to the tip of airfoil improve wind turbine performance. Similarly, change in performance was investigated making notches at different sizes distances on trailing edge wing structure, inspired creatures nature. First all, designed structures analyzed analysis as a fixed wing, lift drag forces examined ...

The aerodynamic interference effects on tiltrotor performance in cruise are investigated using comprehensive calculations, to better understand the physics and to quantify the effects on the aircraft design. Performance calculations were conducted for 146,600-lb conventional and quad tiltrotors, which are to cruise at 300 knots at 4000 ft/95 deg F condition. A parametric study was conducted to ...

Birds have frequently evolved to exploit insular environments by becoming adapted to a terrestrial lifestyle and losing the ability to fly, usually via reducing the wings and pectoral girdle. The enigmatic flightless ibis Xenicibis xympithecus (Threskiornithidae) from the Quaternary of Jamaica provides a rare example of flight loss in ibises. We report on previously undescribed fossils of Xenic...

Whiteness, although frequently apparent on the wings, legs, antennae, or bodies of many species of moths and butterflies, along with other colors and shades, has often escaped our attention. Here, we investigate the nanostructure and microstructure of white spots on the wings of Carystoides escalantei, a dusk-active and shade-inhabiting Costa Rican rain forest butterfly (Hesperiidae). On both m...

Flapping wings continuously create and send vortices into their wake, while imparting downward momentum into the surrounding fluid. However, experimental studies concerning the details of the three-dimensional vorticity distribution and evolution in the far wake are limited. In this study, the three-dimensional vortex wake structure in both the near and far field of a dynamically scaled flappin...

In modern birds (Neornithes), the wing is composed of a layer of long, asymmetrical flight feathers overlain by short covert feathers. It has generally been assumed that wing feathers in the Jurassic bird Archaeopteryx and Cretaceous feathered dinosaurs had the same arrangement. Here, we redescribe the wings of the archaic bird Archaeopteryx lithographica and the dinosaur Anchiornis huxleyi and...

The present work contains theoretical considerations and computational results on the nature of using winglets on wind turbines. The theoretical results presented show that the power augmentation obtainable with winglets is due to a reduction of tip-effects, and is not, as believed up to now, caused by the downwind vorticity shift due to downwind winglets. The numerical work includes optimizati...

SUMMARY Pressure measurements, flow visualisation tests and force measurements have been made on 45' swept half wings, to examine the flow conditions which prevail, particularly in relation to the effectiveness of an upper surface spoiler as a roll control. Tests were made on l/10 scale half-models in the 3ft x 3ft wind tunnel over a Mach number range 0.5 to 0.9. The wing flow is characterised ...