Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flexible Wings Driven by a Simple Oscillation May be Feasible for Designing Efficient Microscale Flying Machines

24.11.2010
In the future, tiny air vehicles may be able to fly through cracks in concrete to search for earthquake victims, explore a contaminated building or conduct surveillance missions for the military. But today, designing the best flying mechanism for these miniature aerial machines is still a challenging task.

Creating micro-scale air vehicles that mimic the flapping of winged insects or birds has become popular, but they typically require a complex combination of pitching and plunging motions to oscillate the flapping wings.

To avoid some of the design challenges involved in mimicking insect wing strokes, researchers at the Georgia Institute of Technology propose using flexible wings that are driven by a simple sinusoidal flapping motion.

“We found that the simple up and down wavelike stroke of wings at the resonance frequency is easier to implement and generates lift comparable to winged insects that employ a significantly more complex stroke,” said Alexander Alexeev, an assistant professor in Georgia Tech’s School of Mechanical Engineering.

Details of the flapping motion proposed by Alexeev and mechanical engineering graduate student Hassan Masoud were presented on Nov. 22 at the 63rd Annual Meeting of the American Physical Society Division of Fluid Dynamics. A paper published in the May issue of the journal Physical Review E also reported on this work, which is supported in part by the National Science Foundation through TeraGrid computational resources.

In nature, flapping-wing flight has unparalleled maneuverability, agility and hovering capability. Unlike fixed-wing and rotary-wing air vehicles, micro air vehicles integrate lifting, thrusting and hanging into a flapping wing system, and have the ability to cruise a long distance with a small energy supply. However, significant technical challenges exist in designing flapping wings, many motivated by an incomplete understanding of the physics associated with aerodynamics of flapping flight at small size scales.

“When you want to create smaller and smaller vehicles, the aerodynamics change a lot and modeling becomes important,” said Alexeev. “We tried to gain insight into the flapping aerodynamics by using computational models and identifying the aerodynamic forces necessary to drive these very small flying machines.”

Alexeev and Masoud used three-dimensional computer simulations to examine for the first time the lift and hovering aerodynamics of flexible wings driven at resonance by sinusoidal oscillations. The wings were tilted from the horizontal and oscillated vertically by a force applied at the wing root. To capture the dynamic interactions between the wings and their environment, the researchers used a hybrid computational approach that integrated the lattice Boltzmann model for fluid dynamics and the lattice spring model for the mechanics of elastic wings.

The simulations revealed that at resonance -- the frequencies when a system oscillates at larger amplitudes -- tilted elastic wings driven by a simple harmonic stroke generated lift comparable to that of small insects that employ a significantly more complex stroke. In addition, the simulations identified one flapping regime that enabled maximum lift and another that revealed maximum efficiency. The efficiency was maximized at a flapping frequency 30 percent higher than the frequency for maximized lift.

“This information could be useful for regulating the flight of flapping-wing micro air vehicles since high lift is typically needed only during takeoff, while the enhanced aerodynamic efficiency is essential for a long-distance cruise flight,” noted Masoud.

To facilitate the design of practical micro-scale air vehicles that employ resonance flapping, the researchers plan to examine how flapping wings can be effectively controlled in different flow conditions including unsteady gusty environments. They are also investigating whether wings with non-uniform structural and mechanical properties and wings driven by an asymmetric stroke may further improve the resonance performance of flapping wings.

John Toon | Newswise Science News
Further information:
http://www.gatech.edu

More articles from Physics and Astronomy:

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

nachricht Next-generation optics offer the widest real-time views of vast regions of the sun
11.01.2017 | New Jersey Institute of Technology

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: 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...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Energy-Efficient Building Operation: Monitoring Platform MONDAS Identifies Energy-Saving Potential

16.01.2017 | Trade Fair News

Designing Architecture with Solar Building Envelopes

16.01.2017 | Architecture and Construction

Sensory Stimuli Control Dopamine in the Brain

13.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>