Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hovering Not Hard if You’re Top-Heavy

14.02.2012
Top-heavy structures are more likely to maintain their balance while hovering in the air than are those that bear a lower center of gravity, researchers at New York University’s Courant Institute of Mathematical Sciences and Department of Physics have found.

Their findings, which appear in the journal Physical Review of Letters, are counter to common perceptions that flight stability can be achieved only through a relatively even distribution of weight—and may offer new design principles for hovering aircraft.

As the Wright brothers demonstrated 100 years ago, the key challenge of flight is maintaining balance. Yet, while insects took to the air 400 million years earlier, their flight stability remains a mystery because of the complex aerodynamics of their flapping wings.

The NYU researchers approached this question by creating experimental conditions needed to achieve stable hovering in mechanical flyers. To do so, they created a range of pyramid-shaped “bugs” constructed from paper that hover when placed in an oscillating column of air, mimicking the effect of flapping wings. They captured the experiment with high-speed videos in order to analyze the nature of the airflow around the bugs.

To gauge which types of structures best maintained their balance, the researchers created paper bugs with various centers of mass. Top-heavy bugs were made by fixing a weight above the pyramid, and low center-of-mass bugs bore this weight below.

Surprisingly, their results showed that the top-heavy bugs hovered stably while those with a lower center of mass could not maintain their balance.

The team showed that when the top-heavy bug tilts, the swirls of air ejected from the far side of the body automatically adjust to keep it upright.

“It works somewhat like balancing a broomstick in your hand,” explained Jun Zhang, a Professor at the Courant Institute and one of the study’s co-authors. “If it begins to fall to one side, you need to apply a force in this same direction to keep it upright.”

For bugs, it is aerodynamical forces that provide this stability.

The lessons learned from these studies could be put to use in designing stable and maneuverable flapping-wing robots.

The study’s other co-authors were postdoctoral researchers Bin Liu, who led the first round experiments, and Leif Ristroph, who came up with the stability theory with Courant Professor Stephen Childress. Another co-author, Annie Weathers, now studies mechanics at the University of Texas, Austin. She took some measurements during her last semester as an undergraduate at NYU.

The study was funded by grants from the National Science Foundation and the U.S. Department of Energy.

James Devitt | Newswise Science News
Further information:
http://www.nyu.edu

More articles from Physics and Astronomy:

nachricht FAST detects neutral hydrogen emission from extragalactic galaxies for the first time
01.07.2020 | Chinese Academy of Sciences Headquarters

nachricht First exposed planetary core discovered
01.07.2020 | Universität Bern

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

Im Focus: A structural light switch for magnetism

A research team from the Max Planck Institute for the Structure of Dynamics (MPSD) and the University of Oxford has managed to drive a prototypical antiferromagnet into a new magnetic state using terahertz frequency light. Their groundbreaking method produced an effect orders of magnitude larger than previously achieved, and on ultrafast time scales. The team’s work has just been published in Nature Physics.

Magnetic materials have been a mainstay in computing technology due to their ability to permanently store information in their magnetic state. Current...

Im Focus: Virtually Captured

Biomechanical analyses and computer simulations reveal the Venus flytrap snapping mechanisms

The Venus flytrap (Dionaea muscipula) takes only 100 milliseconds to trap its prey. Once their leaves, which have been transformed into snap traps, have...

Im Focus: NASA observes large Saharan dust plume over Atlantic ocean

NASA-NOAA's Suomi NPP satellite observed a huge Saharan dust plume streaming over the North Atlantic Ocean, beginning on June 13. Satellite data showed the dust had spread over 2,000 miles.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, Colin Seftor, an atmospheric scientist, created an animation of the dust and aerosols from the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

First exposed planetary core discovered

01.07.2020 | Physics and Astronomy

Energy-saving servers: Data storage 2.0

01.07.2020 | Power and Electrical Engineering

Laser takes pictures of electrons in crystals

01.07.2020 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>