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 A torque on conventional magnetic wisdom
23.07.2019 | University of Illinois College of Engineering

nachricht MOF@SAW: Nanoquakes and molecular sponges for weighing and separating tiny masses
22.07.2019 | Universität Augsburg

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: MOF@SAW: Nanoquakes and molecular sponges for weighing and separating tiny masses

Augsburg chemists and physicists report how they have succeeded in the extremely difficult separation of hydrogen and deuterium in a gas mixture.

Thanks to the Surface Acoustic Wave (SAW) technology developed here and already widely used, the University of Augsburg is internationally recognized as the...

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Hidden dynamics detected in neuronal networks

23.07.2019 | Life Sciences

Towards a light driven molecular assembler

23.07.2019 | Life Sciences

A torque on conventional magnetic wisdom

23.07.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>