By IANS,
Toronto : Researchers are currently developing wing designs that copy the amazing flight of birds by altering the planform of the wings in order to optimise the aerodynamics for a given flight stage.
“When you observe eagles in flight, you would notice that when they are high in the sky they soar and their wings are fully extended. They are gliding, attempting to increase lift and reduce drag,” explained Shaker Meguid from University of Toronto.
“This helps them to glide effortlessly and navigate for long durations in their search for a prey. However, they fold their wings and go on a fast attack when they dive to catch a prey,” he added.
After studying research on birds, in particular Apus apus (common swift), a bird whose wing-morphing ability makes it an especially versatile flyer and allows it to eat, sleep and mate in the air, Meguid began plans to develop a more effective alternative to the traditional fixed-wing aircraft.
“Morphing implies large seamless shape change. Right now we have aircraft control surfaces that allow discrete morphing such as ailerons and flaps. What we want to do is undergo changes in a seamless fashion, resulting in increased efficiency,” he said.
To achieve these seamless transitions in wing shape, Meguid and his research team are combining two types of advanced materials. The first is shape memory alloy (SMA), which contracts when heated above a certain temperature.
The second are piezoelectrics, which compress or extend when an electric field is applied to them. They plan on using these materials to allow the wing to change shape and respond to an aircraft’s changing mission with an overall reduced system complexity, according to a Toronto release.
This three-year project, which was launched in April, is focusing on developing morphing wings specifically for unmanned aerial vehicles (UAVs), aircraft that are often used for surveillance, imaging and operation in locations where human safety is at risk.