Abstract. In this work an alternative beam finite element for rapid time-domain flutter analysis of wings equipped with trailing edge control surfaces, generally distributed along the span, is presented. The aeroelastic proposed based on Euler-Bernoulli theory, De St. Venant torsion theory and two-dimensional unsteady aerodynamics. developed model attractive preliminary aero-servo-elastic analy...

Human pilots have the extraordinary ability to remotely maneuver small Unmanned Aerial Vehicles (UAVs) far outside the flight envelope of conventional autopilots. Given the tremendous thrustto-weight ratio available on these small machines [1, 2], linear control approaches have recently produced impressive demonstrations that come close to matching this agility for a certain class of aerobatic ...

Linear modal instabilities of flow over finite-span untapered wings have been investigated numerically at Reynolds number 400, a range angles attack and sweep on two having aspect ratios 4 8. Base flows generated by direct numerical simulation, marching the unsteady incompressible three-dimensional Navier-Stokes equations to steady state, or using selective frequency damping obtain stationary l...

Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast,...

The wings of many insect species including crane flies and damselflies are petiolate (on stalks), with the wing planform beginning some distance away from the wing hinge, rather than at the hinge. The aerodynamic impact of flapping petiolate wings is relatively unknown, particularly on the formation of the lift-augmenting leading-edge vortex (LEV): a key flow structure exploited by many insects...

BACKGROUND Candidate genes for color pattern formation in butterfly wings have been known based on gene expression patterns since the 1990s, but their functions remain elusive due to a lack of a functional assay. Several methods of transferring and expressing a foreign gene in butterfly wings have been reported, but they have suffered from low success rates or low expression levels. Here, we de...

The fore wings of scale insect males possess reduced venation compared with other insects and the homologies of remaining veins are controversial. The hind wings are reduced to hamulohalterae. When adult males are prepared using the standard methods adopted to females and nymphs, i.e. using KOH to clear the specimens, the wings become damaged or deformed, an so these structures are not usually ...

Today, Flapping Micro Aerial Vehicles (MAV) are used in many different applications. Reynolds Number for this kind of aerial vehicle is about 104 ~ 105 which shows dominancy of inertial effects in comparison of viscous effects in flow field except adjacent of the solid boundaries. Due to periodic flapping stroke, fluid flow is unsteady. In addition, these creatures have some complexities in kin...

Abstract A nonlinear static aeroelastic methodology based on the coupled CFD/CSD approach has been developed to study geometrical behaviors of high-aspect-ratio or multi-material flexible aerial vehicles under aerodynamic loads. The Reynolds-averaged Navier–Stokes solver combined with three-dimensional finite-element is used perform fluid-structure coupling simulation. interpolation technique f...

Abstract Butterfly wings are closely related to the premature failure of rolling element bearings. In this study, butterfly formation is investigated using developed semi-analytical three-dimensional (3D) contact model incorporating inclusion and material property degradation. The 3D elastic field introduced by inhomogeneous solved numerical approaches, which include equivalent method (EIM) con...