We examine the fluid-mechanical interactions that occur between arrays of flapping wings when operating in close proximity at a moderate Reynolds number (Re≈100-1000). Pairs of flapping wings are oscillated sinusoidally at frequency f, amplitude θ_{M}, phase offset ϕ, and wing separation distance D^{*}, and outflow speed v^{*} is measured. At a fixed separation distance, v^{*} is sensitive to b...

It is predicted that the Hα emission line at the early nebular epoch of type II-P supernovae may display robust observational effects of radiation damping wings. Monte Carlo simulations demonstrate that the Hα line with the optical depth typical of the early nebular epoch acquires extended wings and redshift and becomes broader compared to the Sobolev approximation case. The strength of these e...

1. Summary Nonplanar wings offer the possibility of reduced drag compared with planar wings of the same span and lift. However, aircraft are not compared on the basis of drag with fixed span and lift, making the integration and assessment of nonplanar wing concepts complex. This paper deals with some of these issues. A brief review of several concepts from winglets to ring wings is followed by ...

Control of ornithopters is challenging due to the unsteady flow generated by the flapping wings. The research presented in this paper is aimed at developing a sensor-based control methodology. Specifically, a distributed pressure sensing system embedded in the flapping wing surfaces is utilized to provide real-time aerodynamic force estimates to facilitate the development of feedback for an orn...

Detailed morphological investigation, mechanical testing and high-speed cinematography and stroboscopic examination of desert locusts, Schistocerca gregaria, in flight show that their hind wings are adapted to deform cyclically and automatically through the wing stroke and that the deformations are subtly dependent on the wings' structure: their shape, venation and vein design and the local pro...

(21) App1_ NO_; 14/068,235 A micro aerial vehicle capable of controlled transitory or _ sustained gliding ?ight. The vehicle includes a fuselage. A (22) Flled: 0d“ 31’ 2013 pair of articulated Wings are forward of a center of gravity of Related US Application Data the vehicle, the Wings being articulated and having trailing _ _ _ _ edge ?aps, and having actuators for controlling the dihedral (6...

Eleven objects that have been reported as proto-planetary nebula or as young planetary nebulae that show very extended Hα wings are presented. The extension of these wings is larger than 800 km s . Data for two symbiotic stars that show this same characteristic is also presented. Raman scattering is the mechanism that best explains the wings in 10 of the PNe and in the 2 symbiotic stars. In the...

Butterfly wing color patterns are determined during the late larval and early pupal stages. Characterization of wing epithelial cells at these stages is thus critical to understand how wing structures, including color patterns, are determined. Previously, we successfully recorded real-time in vivo images of developing butterfly wings over time at the tissue level. In this study, we employed sim...

Abstract— Evolutionary Algorithms are often used as an optimization tool. We use this ability here to help explore, analyse and, on this basis, propose a controller for a complex robotics system: a flapping wings aircraft. A multi-objective optimization is performed to find the best parameters of sinusoidal wings kinematics. The obtained results are not the end of the process, but rather the be...

Theoretical analyses are presented for the stability of symmetric and asymmetric vortex pairs over slender conical wings and bodies under small perturbations in an inviscid incompressible flow at high angles of attack and sideslip. The three-dimensional problem of a pair of vortices over slender conical wings and bodies is reduced to a problem in two dimensions by using the conical flow assumpt...