The paper reviews recent achievements in the application of smart-materials actuation to counteract aeroelastic and vibration effects in helicopters and fixed wing aircraft. A brief review of the induced-strain actuation principles and capabilities is done first. Attention is then focused on the smart rotor blade applications. Induced twist, active blade tip, and active blade flap are presented...

The paper reviews recent achievements in the application of smart-materials actuation to counteract aeroelastic and vibration effects in helicopters and fixed wing aircraft. A brief review of the induced-strain actuation principles and capabilities is done first. Attention is then focused on the smart rotor blade applications. Induced twist, active blade tip, and active blade flap are presented...

This paper deals with the boundary control problem of a nonhomogeneous flexible wing evolving under unsteady aerodynamic loads. The wing is actuated at its tip by flaps and is modeled by a distributed parameter system consisting in two coupled partial differential equations. Based on the proposed boundary control law, the well-posedness of the underlying Cauchy problem is first investigated by ...

Elliptic differential equations are derived for the generation of structured meshes and difference equations for the generation of smooth hybrid meshes from metric identity. A parabolic procedure is used to march the solution of the difference equations simultaneously for both types of meshes away from surface patches meshed by quads or triangles. An aerodynamic application for the ONERA M6 win...

For an airborne optical system carried by a helicopter, aero-optic aberrations originate primarily from blade tip vortices that pass through the system field of view; these aberrations result from the reduced pressure and density in the vortex cores and the associated variations in the index-of-refraction. Using the weakly compressible model (WCM) previously developed at Notre Dame, aero-optic ...

A flying insect generates aerodynamic forces through the active manipulation of the wing and the “passive” properties of deformability and wing shape. To investigate these “passive” properties, the flexural stiffness of dried forewings belonging to 10 butterfly species was compared to the butterflies’ gross morphological parameters to determine allometric relationships. The results show that fl...

The dynamic, three-dimensional shape of flapping insect wings may influence many aspects of flight performance. Insect wing deformations during flight are largely passive, and are controlled primarily by the architecture and material properties of the wing. Although many details of wing structure are well understood, the distribution of flexural stiffness in insect wings and its effects on wing...

Insects perform fast rotational manoeuvres during flight. While two insect orders use flapping halteres (specialized organs evolved from wings) to detect body dynamics, it is unknown how other insects detect rotational motions. Like halteres, insect wings experience gyroscopic forces when they are flapped and rotated and recent evidence suggests that wings might indeed mediate reflexes to body ...

All natural flyers equip flexible wings. It’s widely thought that the wing flexibility can play important roles in flight aerodynamics. In the current work, a combined experimental and computational method is developed to study the role of morphing wing in hovering dragonfly aerodynamic performance. We start with taking high-speed images of a freely flying dragonfly. Next, a surface reconstruct...

Urophora merzisp. n. reared from flower heads of Centaurea behen Linnaeus is described from Iran. It is similar to Urophora campestris, Urophora sachalinensis, Urophora stylata, Urophora tsoii and Urophora vera in wing pattern with 3 well developed crossbands and indistinct subbasal crossband, differing in aculeus tip with two pairs of diminished preapical steps and different host plants.