We give an explanation for the onset of fluid-flow-induced flutter in a flag. Our theory accounts for the various physical mechanisms at work: the finite length and the small but finite bending stiffness of the flag, the unsteadiness of the flow, the added mass effect, and vortex shedding from the trailing edge. Our analysis allows us to predict a critical speed for the onset of flapping as wel...

Flying animals exhibit remarkable degrees of both stability and manoeuvrability. Our understanding of these capabilities has recently been improved by the identification of a source of passive damping specific to flapping flight. Examining how this damping effect scales among different species and how it affects active manoeuvres as well as recovery from perturbations provides general insights ...

Using a dynamically scaled robotic wing, we studied the aerodynamic torque generation of flapping wings during roll, pitch, and yaw rotations of the stroke plane. The total torque generated by a wing pair with symmetrical motions was previously known as flapping counter-torques (FCTs). For all three types of rotation, stroke-averaged FCTs act opposite to the directions of rotation and are colli...

flapping-wing robotic insects are small, highly maneuverable flying robots inspired by biologicalinsects and useful for a wide range of tasks, including exploration, environmental monitoring, searchand rescue, and surveillance. recently, robotic insects driven by piezoelectric actuators have achievedthe important goal of taking off with external power; however, fully autonomous operation requir...

Numerical simulations have been used to examine the performance of flapping foils. It is envisioned that these flapping foils will be employed as pectoral fins in a bio-robotic AUV (BAUV) and a detailed parametrization of the hydrodynamic performance of these foils will allow for the development of a high-fidelity dynamical model of the BAUV. In the long term, it is expected that this dynamical...

[1] Fast vertical flapping oscillations of the plasma sheet have been observed by Cluster on September 26, 2001. The flapping motion had vertical speeds exceeding 100 km/s, an amplitude in excess of 1 RE and a quasiperiod of 3 min. The current sheet was mostly tilted in the Y-Z plane (with the tilt sometimes exceeding 45 ). The waves had the properties of a kink mode and propagated toward the d...

Recent developments in millimeter-scale fabrication processes have led to rapid progress towards creating airborne flapping wing robots based on Dipteran (two winged) insects. Previous work to regulate forces and torques generated by flapping wings has focused on controlling wing trajectory. An alternative approach uses underactuated mechanisms with tuned dynamics to passively regulate these fo...

A power estimation approach for calculating the of a flapping-wing air vehicle (FWAV) in forward flight is proposed this paper. One challenges and essential points FWAVs endurance. In order to optimize FWAVs, it necessary analyze required addition kinematic aerodynamic analyses prototype. Previously, birds was limited their average power, which assumed lift usually same as gravitational force. ...

1 General Introduction A Flapping Micro Air Vehicle (FMAV) is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Basic open-loop flight control is possible through a radio frequency remote controller with joystick [1]. ...

Most biological flyers undergo orderly deformation in flight, and the deformations of wings lead to complex fluid-structure interactions. In this paper, an aerodynamic-structural coupling method of flapping wing is developed based on ANSYS to simulate the flapping of flexible wing. Firstly, a three-dimensional model of the cicada’s wing is established. Then, numerical simulation method of unste...