Some other cool things that make dragonflies the best fliers that scientist want to emulate. They have at least four distinct flight styles. They are; Odonata: counter-stroking (where fore- and hind-wings move up and down about 180 degrees out of phase), phased-stroking (where the hind-wings cycle about 90 degrees - a quarter cycle - before the fore-wings), synchronised-stroking (where fore- and hind-wings move in unison), and gliding.
Counter-stroking is the normal mode when they are hovering or flying very slowly. This is an efficient way of flying and generates a lot of lift.
Phased-stroking is used when flying about. This method generates more thrust but less lift than counter-stroking.
Synchronised-stroking is used when maximizing thrust to change direction quickly. It is also used as a display flight, showing off the colored wings.
Gliding is also used. Three kinds of gliding can be recognized:
- free gliding, where an animal just stops stroking with its wings and glides slowly down for a few seconds.
- updraft gliding at hill crests, where the animal adjusts its wing positioning to float in the air without the need to beat its wings.
- and gliding in towed females, where a female in the wheel position holds her wings out and glides while the male provides the motive force.
Thrust generating mechanisms in dragonflies are complex. Whereas aircraft use only two methods for generating lift (and one of these only for very short periods) dragonflies use at least four distinct physical processes:
- classical lift,
- super-critical lift,
- and vortex shedding.
Dragonfly wings are very dynamic structures. They are not simple planar objects. The corrugations in the wing hold an aerofoil of air around the physical wing, lowering friction, and the wings flex around several axes, responding both to muscle actions and to inertia effects. The pterostigma on the leading edge near the tip is a weight that causes the wing tip area to flex during a wing stroke, improving aerodynamic efficiency.
To make things more impressive, dragonflies can fly with different wings doing quite different things, even using different methods to generate thrust. Asymmetric wing stroking in damselflies permits wings on one side to drive forward, and the other side to drive back, spinning the animal on its axis in a single combined stroke. All dragonflies achieve their mastery of flight by varying what their wings are doing in a coordinated fashion. They can adjust wing shape, stroke length, angle of attack, move a wing forward (or backwards) of its "usual" position, stop one or two wings, adjust relationships between any two wings on either side of the body ... the list goes on.
Oh most of this is borrowed from this link: I ain't that geeky yet...
Here are Some Cool Pics.