Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

Alejandro Ortega Ancel; Rodney Eastwood; Daniel Vogt; Carter Ithier; Michael Smith; Rob Wood; Mirko Kovač

doi:10.1098/rsfs.2016.0087

Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

Interface Focus. 2017 Feb 6;7(1):20160087. doi: 10.1098/rsfs.2016.0087.

Authors

Alejandro Ortega Ancel¹, Rodney Eastwood², Daniel Vogt³, Carter Ithier³, Michael Smith³, Rob Wood³, Mirko Kovač¹

Affiliations

¹ Department of Aeronautics , Imperial College London , London , UK.
² Museum of Comparative Zoology , Harvard University , Cambridge, MA , USA.
³ Wyss Institute for Biologically Inspired Engineering , Harvard University , Cambridge, MA , USA.

Abstract

Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s^-1. The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested.

Keywords: butterfly wings; computational fluid dynamics; gliding; micro-robots; wind tunnel.