Soaring towards greater UAV endurance using urban updrafts

Most people who have cast their eyes skyward – or seen a nature documentary or two – will have seen lazily circling birds soaring to greater heights without flapping their wings. These soaring birds are catching a ride on rising air currents to save energy, and now researchers at RMIT University in Melbourne, Australia, are aiming to develop bio-inspired UAVs capable of doing the same thing.
Working in collaboration with the Australian Department of Defence's Defence Science and Technology Organisation (DSTO), the RMIT research team is aiming to develop a small fixed-wing unmanned aircraft that is able to autonomously take advantage of rising air currents around buildings to save energy and improve endurance.
"Birds make soaring look easy, but when we try to mimic what they know by instinct, we realize just how far advanced nature is in its designs," says Dr Reece Clothier, who is the lead researcher on the project.
Although the long-term goal is to design a soaring UAV, the researchers will first focus on proving the feasibility of "urban" soaring. This will involve the use of real-time wind-sensing systems and complex flow models to identify the location of possible updrafts around large buildings.

"Small aircraft used for communications relay or surveillance and reconnaissance could greatly benefit by having a means of exploiting naturally occurring updrafts and avoiding the deleterious effects of turbulence in urban environments," says Dr Jennifer Palmer, a Senior Research Scientist in the Aerospace Division of DSTO.