PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

How the hummingbird achieves its aerobatic feats

How the hummingbird achieves its aerobatic feats
2014-11-24
(Press-News.org) VIDEO: The most detailed aerodynamic simulation of hummingbird flight conducted to date demonstrates that it achieves its aerobatic abilities through a unique set of aerodynamic forces more closely aligned to those...
Click here for more information.

The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How do they do it?

Now, the most detailed, three-dimensional aerodynamic simulation of hummingbird flight conducted to date has definitively demonstrated that the hummingbird achieves its nimble aerobatic abilities through a unique set of aerodynamic forces that are more closely aligned to those found in flying insects than to other birds.

The new supercomputer simulation was produced by a pair of mechanical engineers at Vanderbilt University who teamed up with a biologist at the University of North Carolina at Chapel Hill. It is described in the article "Three-dimensional flow and lift characteristics of a hovering ruby-throated hummingbird" published this fall in the Journal of the Royal Society Interface.

For some time researchers have been aware of the similarities between hummingbird and insect flight, but some experts have supported an alternate model which proposed that hummingbird's wings have aerodynamic properties similar to helicopter blades. However, the new realistic simulation demonstrates that the tiny birds make use of unsteady airflow mechanisms, generating invisible vortices of air that produce the lift they need to hover and flit from flower to flower.

You might think that if the hummingbird simply beats its wings fast enough and hard enough it can push enough air downward to keep its small body afloat. But, according to the simulation, lift production is much trickier than that.

For example, as the bird pulls its wings forward and down, tiny vortices form over the leading and trailing edges and then merge into a single large vortex, forming a low-pressure area that provides lift. In addition, the tiny birds further enhance the amount of lift they produce by pitching up their wings (rotate them along the long axis) as they flap.

Hummingbirds perform another neat aerodynamic trick - one that sets them apart from their larger feathered relatives. They not only generate positive lift on the downstroke, but they also generate lift on the upstroke by inverting their wings. As the leading edge begins moving backwards, the wing beneath it rotates around so the top of the wing becomes the bottom and bottom becomes the top. This allows the wing to form a leading edge vortex as it moves backward generating positive lift.

According to the simulation, the downstroke produces most of the thrust but that is only because the hummingbird puts more energy into it. The upstroke produces only 30 percent as much lift but it takes only 30 percent as much energy, making the upstroke equally as aerodynamically efficient as the more powerful downstroke.

Large birds, by contrast, generate almost all of their lift on the downstroke. They pull in their wings toward their bodies to reduce the amount of negative lift they produce while flapping upward.

Although hummingbirds are much larger than flying insects and stir up the air more violently as they move, the way that they fly is more closely related to insects than it is to other birds, according to the researchers.

Insects like dragonflies, houseflies and mosquitoes can also hover and dart forward and back and side to side. Although the construction of their wings is much different, consisting of a thin membrane stiffened by a system of veins, they also make use of unsteady airflow mechanisms to generate vortices that produce the lift they need to fly. Their wings are also capable of producing positive lift on both upstroke and downstroke.

To capture the details of the aerodynamics of the hummingbird's ability to hover, Tyson Hedrick, associate professor of biology at UNC, put tiny dabs of non-toxic paint at nine places on a female ruby-throated hummingbird's wing. Then he took high-speed videos at 1,000 frames per second with four cameras while the bird hovered in front of an artificial flower.

Then at Vanderbilt Haoxiang Luo, associate professor of mechanical engineering, and doctoral student Jialei Song took the video, extracted data on the position of the points in three dimensions and reconstructed the varying wing shape and position for a full flapping cycle.

Using the super-computers at the National Science Foundation's Extreme Science and Engineering Discovery Environment (XSEDE) and at Vanderbilt's Advanced Computing Center for Research and Education, the engineers created a fluid-dynamic model that simulated the thousands of tiny vortices that the hummingbird's wings create and so was able to reproduce the complex web of forces that allow these tiny miracles of nature to fly.

INFORMATION:

The research was funded by National Science Foundation grants CBET-0954381 and IOS-0920358.

Visit Research News @ Vanderbilt for more research news from Vanderbilt. [Media Note: Vanderbilt has a 24/7 TV and radio studio with a dedicated fiber optic line and ISDN line. Use of the TV studio with Vanderbilt experts is free, except for reserving fiber time.]


[Attachments] See images for this press release:
How the hummingbird achieves its aerobatic feats How the hummingbird achieves its aerobatic feats 2

ELSE PRESS RELEASES FROM THIS DATE:

The Lancet: Universal health coverage for US military veterans within reach, but many still lack coverage

2014-11-24
Over a million US military veterans lacked healthcare coverage in 2012, according to new estimates published in The Lancet. While many people believe that all veterans are covered by the Veterans Affairs health care system, less than half (8.9 million) of the 22 million veterans in the US are covered by VA health benefits, and most veterans are covered by private health insurance. Uninsured veterans are more likely to be young, single, African American, and veterans of Iraq and Afghanistan. However, the authors of this viewpoint estimate that universal health coverage ...

Declining loneliness among American teenagers

2014-11-24
There has been a growing concern that modern society is increasingly lonely. In 2006, a New York Times article "The Lonely American Just Got a Bit Lonelier" highlighted research that shows a decline in social engagement--people are less likely to join clubs, have fewer close friends, and are less likely to perceive others as trustworthy. However, studies have also shown an increase in extraversion and self-esteem, which suggests loneliness is decreasing. In an effort to study the societal trend of loneliness, researchers from the University of Queensland and Griffith ...

Motor coordination issues in autism are caused by abnormal neural connections

2014-11-24
Abnormal connections between neurons are the likely cause of motor coordination issues seen in autism spectrum disorder. Using a mouse model of autism, scientists from the University of Chicago identified a malfunctioning neural circuit associated with reduced capacity for motor learning. This appears to arise from an inability to eliminate unneeded neural connections in the brain. They report their findings Nov. 24 in Nature Communications. "We have identified synaptic abnormalities that may play a role in motor problems typically seen in children with autism," said ...

Adult survivors of childhood eye cancer experience few cognitive or social setbacks

2014-11-24
Adult survivors of retinoblastoma, a type of eye cancer that usually develops in early childhood, have few cognitive or social problems decades following their diagnosis and treatment. That's the conclusion of a study published early online in CANCER, a peer-reviewed journal of the American Cancer Society. The findings offer good news for patients, but it's important to continue to monitor for long-term effects as the brain changes throughout life. While most children with retinoblastoma are successfully cured, little is known about the long-term health of survivors. ...

Healthy gut microbiota can prevent metabolic syndrome, researchers say

Healthy gut microbiota can prevent metabolic syndrome, researchers say
2014-11-24
ATLANTA--Promoting healthy gut microbiota, the bacteria that live in the intestine, can help treat or prevent metabolic syndrome, a combination of risk factors that increases a person's risk for heart disease, diabetes and stroke, according to researchers at Georgia State University and Cornell University. Their findings are published in the journal Gastroenterology. The study, a follow-up to the research team's previous paper in Science, uses an improved technical approach, making the results more significant. The research team includes Dr. Andrew Gewirtz, a professor ...

Schizophrenia may be triggered by excess protein during brain development

2014-11-24
A gene associated with schizophrenia plays a role in brain development and may help to explain the biological process of the disease, according to new Rutgers research. In the study, published in Biological Psychiatry, Bonnie Firestein, professor in the Department of Cell Biology and Neuroscience, says too much protein expressed by the NOS1AP gene, which has been associated with schizophrenia, causes abnormalities in brain structure and faulty connections between nerve cells that prevent them from communicating properly. Firestein's research indicates that an overabundance ...

The sound of status: People know high-power voices when they hear them

2014-11-24
Being in a position of power can fundamentally change the way you speak, altering basic acoustic properties of the voice, and other people are able to pick up on these vocal cues to know who is really in charge, according to new research published in Psychological Science, a journal of the Association for Psychological Science. We tend to focus on our words when we want to come across as powerful to others, but these findings suggest that basic acoustic cues also play an important role: "Our findings suggest that whether it's parents attempting to assert authority over ...

Mutant protein takes babies' breath away

2014-11-24
Babies start breathing in the womb, inhaling and exhaling irregularly at first, and then gradually more and more, until the day when they're born and have to do it all the time. But premature babies sometimes have trouble. They stop breathing periodically, sometimes for 20 or 30 seconds at a time. Sometimes they're fine, and sometimes they're not, and doctors struggle to help them. That may soon change, however, thanks to a two-month-old patient at UConn Health with a rare connexin mutation, and his doctor's willingness to call for help. The resulting collaboration between ...

Suicide risk falls substantially after talk therapy

2014-11-24
Repeat suicide attempts and deaths by suicide were roughly 25 percent lower among a group of Danish people who underwent voluntary short-term psychosocial counseling after a suicide attempt, new Johns Hopkins Bloomberg School of Public Health-led research suggests. The findings are believed to be the first to show that talk therapy-focused suicide prevention actually works, averting future suicide attempts in this very high-risk population. Although just six-to-ten talk therapy sessions were provided, researchers found long-term benefits: Five years after the counseling ...

The Lancet: Universal health coverage for US militar veterans within reach, but many still lack coverage

2014-11-24
Over a million US military veterans lacked healthcare coverage in 2012, according to new estimates published in The Lancet. While many people believe that all veterans are covered by the Veterans Affairs health care system, less than half (8.9 million) of the 22 million veterans in the US are covered by VA health benefits, and most veterans are covered by private health insurance. Uninsured veterans are more likely to be young, single, African American, and veterans of Iraq and Afghanistan. However, the authors of this viewpoint estimate that universal health coverage ...

LAST 30 PRESS RELEASES:

UK/Portuguese study strongly suggests antibiotic-resistant “superbugs” are being passed from cats and dogs to their owners

Researchers study effects of solvation and ion valency on metallopolymers

Physicists solve puzzle about ancient galaxy found by Webb telescope

Clear guidelines needed for synthetic data to ensure transparency, accountability and fairness study says

Report finds significant gender and racial inequities in the educational measurement profession

University of Houston and Scotland’s Heriot-Watt University forge strategic energy alliance

Rice team demonstrates miniature brain stimulator in humans

Jennifer Stinson receives prestigious Barer-Flood Prize in health services research

First insights into the genetic bottleneck characterizing early sheep husbandry in the Neolithic period

Theories that explain the crisis in democracy are inadequate for Latin America, experts say

Starving cells hijack protein transport stations

Where have all the right whales gone?

Researchers find no link between COVID-19 virus and development of asthma in children

Cell’s ‘garbage disposal’ may have another role: helping neurons near skin sense the environment

Study reveals potential to reverse lung fibrosis using the body’s own healing technique

International team co-led by a BSC researcher discovers more than 50 new deep-sea species in one of the most unexplored areas of the planet

Cleveland Innovation District partners exceeding many targets set by state and JobsOhio

A third of women experience migraines associated with menstruation, most commonly when premenopausal

MD Anderson Research Highlights for April 12, 2024

Soft Robotics appoints new Deputy Editor-in-Chief, Barbara Mazzolai, PhD

Wiley releases Mass Spectra of Designer Drugs 2024 to accelerate forensics analysis of fentanyls, cannabinoids, and more

Freestanding emergency departments are popular, but do they function as intended?

University of Cincinnati experts present at national neurology conference

Bonobos are more aggressive than previously thought

How seaweed became multicellular

Melanomas resist drugs by ‘breaking’ genes

Africa’s iconic flamingos threatened by rising lake levels, study shows

Vaccination timeliness among US children ages 0-19 months

Changes in permanent contraception procedures among young adults following the Dobbs decision

Semaglutide vs endoscopic sleeve gastroplasty for weight loss

[Press-News.org] How the hummingbird achieves its aerobatic feats