Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NYU’S Childress demonstrates tool for studying hovering flight at international science meeting

21.02.2006


A tool for examining hovering flight of insects and birds could allow researchers to study other matters pertaining to locomotion, Stephen Childress, a professor at New York University’s Courant Institute of Mathematical Sciences, demonstrated at the American Association for the Advancement of Science (AAAS) annual meeting in St. Louis. The findings were part of a symposium, "How Insects Fly," which also included researchers from Cornell University and the California Institute of Technology.



Previous research in this area was conducted through observations of a small pteropod mollusk, or "sea butterfly," whose locomotion in water is similar to that of a butterfly’s flight. That revealed two modes of locomotion: in one, cilia mode, the organism swims forward much like a micro-organism, using waves of beating cilia, or hair-like structures; in another, flapping mode, the wings are extended and flapped back and forth in a symmetrical manner, propelling the body forward. These results showed that this particular organism was able to use both modes: one pertaining to the microorganisms, the other to the insects or birds. As the pteropods grew, observations by Childress with his colleague, Robert Dudley, a biologist at the University of California, Berkeley, showed that the wings enabled more rapid swimming. Extrapolating the data backwards to small size, it was found that wings ceased to be effective at a critical size, establishing a transition size for winged flight.

Building on this scholarship, Childress and his colleagues at the Courant Institute’s Applied Mathematics Laboratory sought ways to study free flight in the laboratory. They first replicated the forward flight of the pteropod by driving a horizontal rigid blade in a vertical oscillation while immersed in fluid. The blade was mounted on a vertical shaft, free to rotate in either direction. The blade flapped horizontally according to Newton’s law of motion. It was found that the transition seen in the pteropods occurred also with the flapping blade. The transition depends upon both the size of the blade and the frequency of flapping. The researchers were thus able to study the transition by varying the frequency instead of the size. Below a certain frequency the blade ceased to rotate.


To simulate the hovering flight of a flapping body, the researchers created a vertical "oscillating wind tunnel," by using a large speaker operated in the range 10-100 Hertz and driving an oscillating column of air in a vertical, cylindrical flight chamber. They then simulated a bug using a small winged body made of paper and placing it in the airflow. The wings are driven to flap and the bug hovers in the flow. This allows analysts to compare the hovering of a passive flexible body in an oscillating airflow with that of an active flapper. The researchers then measured the minimum airflow amplitude needed for geometrically similar bugs of various sizes to hover in the oscillating air and were able to show how the optimal flapping frequency changes with size.

Childress and his colleagues are presently comparing these observations of free passive flapping flight with models of insect flight. The work promises to provide a new approach to the study of flapping flight, enabling studies of free hovering of winged bodies.

James Devitt | EurekAlert!
Further information:
http://www.nyu.edu

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>