Stroke plane angle controls leading edge vortex in a bat-inspired flapper

The present interest in micro air vehicles has given the research on bat flight a new impulse. With the use of high speed cameras and improved PIV techniques, the kinematics and aerodynamics of bats have been studied in great detail. A robotic flapper makes it possible to do measurements by systematically changing only one parameter at a time and investigate the parameter space outside the natural flight envelope of bats without risking animal safety. For this study, a robotic flapper (RoBat), inspired by Leptonycteris yerbabuenae was developed and tested over the speed range 1-7 m/s, with variable maximum angles of attacks (AoA(max) = 55 degrees and 15 degrees, respectively) and constant AoA(max). = 55 degrees. These measurements show the presence of a leading edge vortex (LEV) for low speeds and a fully attached flow for high speeds at low AoA(max), which is in line with natural bat flight. A LEV occurs for AoA(max) = 55 degrees throughout the complete flight speed range, and throughout which the LEV circulation coefficient remains rather constant. This implies that bats and micro air vehicles could use LEVs for high load maneuvers also at relatively high flight speeds. However, at high flight speeds the LEV bursts, which causes increased drag, most likely due to a decrease in Strouhal number. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Muijres, FlorianLund University,Lunds universitet,Evolutionär ekologi,Biologiska institutionen,Naturvetenskapliga fakulteten,Evolutionary ecology,Department of Biology,Faculty of Science(Swepub:lu)teor-fim (författare)
Johansson, ChristofferLund University,Lunds universitet,Evolutionär ekologi,Biologiska institutionen,Naturvetenskapliga fakulteten,Evolutionary ecology,Department of Biology,Faculty of Science(Swepub:lu)teor-cjo (författare)
Stuiver, Melanie (författare)
van Oudheusden, Bas W. (författare)
Hedenström, AndersLund University,Lunds universitet,Evolutionär ekologi,Biologiska institutionen,Naturvetenskapliga fakulteten,Evolutionary ecology,Department of Biology,Faculty of Science(Swepub:lu)ekol-ahe (författare)
Evolutionär ekologiBiologiska institutionen (creator_code:org_t)

Ingår i:Comptes Rendus. Mecanique: Elsevier BV340:1-2, s. 95-1061873-72341631-0721

Av författaren/redakt...: Koekkoek, Gide; Muijres, Florian; Johansson, Chris ...; Stuiver, Melanie; van Oudheusden, ...; Hedenström, Ande ...

Om ämnet

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.