This paper presents an experimental investigation of the evolution of the leading-edge vortex and spanwise flow generated by an insect-like flappingwing at a Reynolds number relevant to flapping-wing micro air vehicles (FMAVs) (Re =∼ 15000). Experiments were accomplished with a firstof-its-kind flapping-wing apparatus. Dense pseudo-volumetric particle image velocimetry (PIV) measurements from 1...

In the “modified quasi-steady” approach, two-dimensional (2D) aerodynamic models of flapping wing motions are analyzed with focus on different types of wing rotation and different positions of rotation axis to explain the force peak at the end of each half stroke. In this model, an additional velocity of the mid chord position due to rotation is superimposed on the translational relative veloci...

I nsects and hummingbirds remain unmatched in their aerodynamic ability to hover in place in addition to other acrobatic feats such as flying backward and sideways by exploiting flapping-wing motion [1]. Although this remarkable ability is key to making small-scale aircraft, flapping-hovering behavior has been difficult to reproduce artificially because of the challenging stability, power, and ...

While biological flyers often display deformed wing structures, the effects of flexibility on the flapping wing aerodynamics remain inadequately understood. We investigate the lift generation and phase dynamics of a flapping flexible wing in hover, between Reynolds number of 100 and 1000 corresponding to small insects, using fully coupled Navier-Stokes equation and linear beam model. The γ scal...

Aerodynamic performance and agility during flapping flight are determined by the combination of wing shape and kinematics. The degree of morphological and kinematic optimisation is unknown and depends upon a large parameter space. Aimed at providing an accurate and computationally inexpensive modelling tool for flapping-wing aerodynamics, we propose a novel CFD (computational fluid dynamics)-in...

Fidicina mannifera Fab. (mass 3 g) can fly at a body temperature of 22 °C, but take-off is usually preceded by an endothermic warm-up that elevates Tth to 28 °C or higher. Warm-up is accompanied by slow, almost imperceptible, wing movements, gentle abdominal pumping and an increase in V02 to about 16 times the resting level. During wing-flapping in fixed flight, V02 increases explosively to abo...

Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results f...

The morphology, kinematics and stiffness properties of lifting surfaces play a key role in the aerodynamic performance of vertebrate flight. These surfaces, as a result of their flexible nature, may move both actively, owing to muscle contraction, and passively, in reaction to fluid forces. However, the nature and implications of this fluid-structure interaction are not well understood. Here, w...

A diversity of efficient solutions for flapping flight have evolved in nature; however, it is often difficult to isolate the key characteristics of efficient flapping flight from biological constraints. Rather than base micro aerial vehicle (MAV) design on natural flyers alone, we propose a multi-fidelity computational approach for analysis and design. At the lowest fidelity level, we use a wak...

Miniature flapping flight systems hold great promise in matching the agility of their natural counterparts, bees, flies, and hummingbirds. Characterized by reciprocating wing motion, unsteady aerodynamics, and the ability to hover, insect-like flapping flight presents an interesting locomotion strategy capable of functioning at small size scales and is still a current focus of research. A vehic...