Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Wind tunnel experiments award flight certificate to bats

What’s the similarity between a bumblebee and a hummingbird? None – apart from one thing: neither the bumblebee nor the hummingbird should be ebale to fly according to classic wing theory. Yet, this is what they do for a living.

In 1995 the conundrum of bumblebee flight got its final solution. And this week the aerodynamics of a hovering bat species has been revealed. Its flight was studied in the wind tunnel laboratory of Lund University, and the results are published in the prestigious journal Science.

The wind tunnel at Lund University is specially crafted for research on bird flight. Birds fly “at the spot” against a headwind, allowing detailed investigation of wing movements using high speed video cameras. It’s also possible to visualize the vortices around the wings and in the wake using fog as tracer particles.

In 2003 professor Anders Hedenström investigated the aerodynamics of bird flight using this method for the first time. In the spring 2007 his lab presented results from applying this method to flying bats for the first time. A nectar-feeding bat species, Palla’s long-tongued bat, was trained to visit a feeder in the wind tunnel. By varying the speed between 0 m/s (hovering) to 7 m/s, different behaviors were studied.

... more about:
»Flight »Hedenström »Tunnel »vortices

"When we investigated the aerodynamics of our bats we discovered that the wings generated more lift than they should at the slowest speeds (as dictated by classic wing theory),"says professor Hedenström.

"We recorded vortices shed in the wake, which we know well from our previous studies on birds. Now, our new study show that a stable leading edge vortex (LEV) is developed on top of the wing, and this vortex adds significant amounts of lift. Such vortices were previously known in insects, for example in bumblebees, and it was the discovery of leading edge vortices that finally resolved the bumblebee flight conundrum."

How can the bats generate such high lift? One of the team members and lead author of the new study, Florian Muijres, explains:

"The high lift arises because the bats can actively change the shape (curvature) by their elongated fingers and by muscle fibers in their membranous wing. A bumblebee cannot do this; its wings are stiff. This is compensated for by the wing-beat frequency. Bats beat their wings up to 17 times per second while the bumblebee can approach 200 wing-beats per second."

The paper in Science is: Leading-Edge Vortex Improves Lift in Slow-Flying Bats, authors are F T Muijres, L C Johansson, R Barfield, M Wolf, G R Spedding and A Hedenström.

Image legends:
The bats are highly maneuverable and can make quick turns during flights
(Photo: L C Johansson, M Wolf, A Hedenström)
Vortex system on the bat’s wings – it is the vortex along the leading edge that is now described for the first time

Ingela Björck | alfa
Further information:

Further reports about: Flight Hedenström Tunnel vortices

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>