New PhD thesis from Animal Flight Lab

Florian Muijres has received his thesis from the printer and is busy distributing them. The thesis contains seven different studies about aerodynamic performance in bats and birds. Two papers describe a high lift mechanism - Leading Edge Vortex - used by bats and pied flycatchers when flying slowly. This vortex enhances lift by 40% or more in these vertebrates, and before Florians work it was thought to be a typical insect mechanism. In other papers time-resolved PIV is used to work out aerodynamic efficiency of bats and birds, and to evaluate an adaptation of the classic actuator concept of flapping flight. Florian is to be congratulated to marvelous thesis, which is not only interesting on the inside but also beautiful on the outside. The public defense will take place on 28 April at 10:00 am, in the Blue Lecture Hall, Ecology Building, Lund. As faculty opponent we are very glad to welcome Professor Tom Daniel, University of Washington, Seattle.

Animal Flight Lab on Bat Conference, Prague

Members of the Animal Flight Lab are currently attending the 15^th International Bat Research Conference in Prague. This is the main outlet for bat science, being the biggest assemblage of bat scientists ever at 550 individuals. In the afternoon on Monday (23 August) we had the flight symposium, organised by Anders H and Sharon Swartz, Brown University. Members of both the Lund and Brown labs gave excellent presentations, showing how kinematics and PIV data could be used to get lots of information (Florian Muijres and Rhea von Busse). Other talks were on flight mechanical constraints on bat size (Ulla Lindhe Norberg), context-dependent flight speeds (Marc Holderied), energetics by Na-Bicarbonate isotope analysis (Christian Voigt), and muscle and tendon morphology in the wings (Sharon Swartz). In the evening, the whole group of speakers went in to Prague for a excellent dinner at a restaurant (Café du Paris, see picture). After dinner we strolled through central Prague and into the old city. Today (Tuesday, 24 August) we have enjoyed many more interesting talks, and soon we will attend the poster session, where Melanie Stuiver will present her poster on the bat robot (RoBat).

New paper on LEV

In a new paper by Tatjana Hubel and Ca Tropea published in J Exp Biol, the occurence of LEV in model wings is investigated. The wings are large, goose size, and the kinematics resemble that of a large bird as well. Still, these wings develop LEVs associated with a delayed stall. These results suggest that even relatively simple kinematics of forward flight in largish birds are potent in developing non-ignorable LEVs associated with unsteady aerodynamic effects. The authors also raise the question whether the quasi-steady approach to bird flight, as adopted in the most popular flight models, perhaps now should be reconsider. I anticipate we will need to discuss this in the near future.