title: The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.
abstract: Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.
authors.affiliation: Department of Biology, Lund University, Lund, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Henningsson
authors.affiliation: LaVision GmbH, Göttingen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Michaelis
authors.affiliation: Structure and Motion Laboratory, Royal Veterinary College, University of London, London, UK.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nakata
authors.affiliation: German Aerospace Centre (DLR), Göttingen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schanz
authors.affiliation: German Aerospace Centre (DLR), Göttingen, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Geisler
authors.affiliation: German Aerospace Centre (DLR), Göttingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schröder
authors.affiliation: Structure and Motion Laboratory, Royal Veterinary College, University of London, London, UK rbomphrey@rvc.ac.uk.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bomphrey
mesh_terms: D000818:Animals; D005426:Flight, Animal / Q000502:physiology*; D006110:Grasshoppers / Q000502:physiology*; D008954:Models, Biological; D012212:Rheology; D014921:Wings, Animal / Q000502:physiology*
keywords: aerodynamics; animal flight; desert locust; span efficiency; tomographic particle image velocimetry; wake deformation