Ignazio Maria Viola from University of Edinburgh
28 April 2021. 13.00 CEST
Imagine if we could fly small drones that remain airborne for days, monitoring the environment, searching for pollutants, and tracking airborne coronaviruses. Unfortunately, this is not yet possible,
because when we try flying insect-scale drones, they can remain airborne only few minutes. Insects, in fact, are inefficient flyers that need to spend most of their time eating to power their flight. But there are in nature flyers, as small as insects, that are very efficient. One of the most extraordinary examples is the dandelion seed. It takes off from 30 cm from the ground, and travels for hundreds of kilometres powered only by the wind. We found that the dandelion uses a porous wing made of a bundle of bristles, known as the pappus, which enhances the drag to slow down its descent. When the dandelion falls, the air flows through the pappus and forms a bubble of recirculating flow. This bubble, which we named the separated vortex ring, sits stably just above the dandelion, like a halo. This discovery suggests the existence in nature of a new way of flying, through virtual wings that are made only of few hairs. This should remind us that nature can be a tremendous source of inspiration, that can underpin future disruptive technologies that do not exploit it, but learn from it.
- A Separated Vortex Ring Underlies the Flight of the Dandelion
- The Effect of Permeability on the Flow Past Permeable Disks at Low Reynolds Numbers
Ignazio Maria Viola
Dr Ignazio Maria Viola is Reader (Associate Professor) at the School of Engineering of the University of Edinburgh and a Fellow of the Royal Institution of Naval Architects. His research group, the Vortex Interaction Laboratory (VOILAb, https://voilab.eng.ed.ac.uk), focuses on how vortical flow structures interact with wings, blades, and sails. Vortex-dominated flow is frequent in nature, which is a key source of inspiration for his research. Ignazio has written more than 100 peer-reviewed conference and journal articles, for which he has been awarded two Medals of Distinction and one Medal of Exceptional Merit by the Royal Institution of Naval Architects. He has contributed to securing research grants in the excess of £15M and is currently leading an ERC Consolidator Grant project on dandelion-inspired flyers (https://edin.ac/2K0WiXD), and an EPSRC project on bio-inspired morphing blades for tidal turbines (https://edin.ac/3agYAMm).