The butterfly Pierella luna (Nymphalidae) shows an intriguing rainbow iridescence effect: the forewings of the male, when illuminated along the axis from the body to the wing tip, decompose a white light beam as a diffraction grating would do. Violet light, however, emerges along a grazing angle, near the wing surface, while the other colors, from blue to red, exit respectively at angles progre...

Various configurations of aircraft wing tip devices have been investigated by performing 3D aerodynamics analysis. The wing tip device in this study was derived from the wing tips of a soaring bird, featuring three smoothly blended elements. Each multi-winglet configuration was integrated into a complete wing-tail-body aircraft configuration. Geometry of each of the three elements in the multi-...

Conceptual wing design analysis methods are combined with numerical optimization to find minimum drag wings subject to constraints on lift, weight, pitching moment, and stall speed. Minimum drag tip extensions and winglets are compared using nonlinear optimization. The minimum drag trapezoidal tip device depends on the ratio of the maneuver lift coefficient to the cruise lift coefficient, altho...

Experiments have been carried out at sub-critical Reynolds number to investigate free-to-roll motions induced by forebody and/or wings complex flow on a 30° swept back nonslender wings-slender body-model for static and dynamic (pitch-up) cases. For the dynamic (pitch-up) case it has been observed that roll amplitude decreases and lag increases with increase in pitching speed. Decrease in roll a...

Flapping-wing kinematics for insect flight has been studied for decades, especially since engineers became interested in flapping-wing micro air vehicles (FWMAVs). Previous work mainly focused on understanding kinematic patterns employed by different insects from the perspective of their trajectories and aerodynamics, and on optimization of kinematic parameters to enhance the understanding. How...

Recent studies have demonstrated that a quasi-steady model closely matches the instantaneous force produced by an insect wing during hovering flight. It is not clear, however, if such methods extend to forward flight. In this study we use a dynamically scaled robotic model of the fruit fly Drosophila melanogaster to investigate the forces produced by a wing revolving at constant angular velocit...

We describe an algorithm for automated generation of multi-parted airplane wings from a cross-section given by a point cloud and the top view of the wing. The relative thickness of the wing (thickness/chord) can be varied from section to section. A rounded tip with two design parameters and GC1-continuity at the crossing to the wing is automatically computed. Constrained approximation and fairi...