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

Study finds ionic thrusters generate efficient propulsion in air

Thrusters powered by ionic wind may be an efficient alternative to conventional atmospheric propulsion technologies

2013-04-03
(Press-News.org) CAMBRIDGE, MA -- When a current passes between two electrodes — one thinner than the other — it creates a wind in the air between. If enough voltage is applied, the resulting wind can produce a thrust without the help of motors or fuel.

This phenomenon, called electrohydrodynamic thrust — or, more colloquially, "ionic wind" — was first identified in the 1960s. Since then, ionic wind has largely been limited to science-fair projects and basement experiments; hobbyists have posted hundreds of how-to videos on building "ionocrafts" — lightweight vehicles made of balsa wood, aluminum foil and wire — that lift off and hover with increased voltage.

Despite this wealth of hobbyist information, there have been few rigorous studies of ionic wind as a viable propulsion system. Some researchers have theorized that ionic thrusters, if used as jet propulsion, would be extremely inefficient, requiring massive amounts of electricity to produce enough thrust to propel a vehicle.

Now researchers at MIT have run their own experiments and found that ionic thrusters may be a far more efficient source of propulsion than conventional jet engines. In their experiments, they found that ionic wind produces 110 newtons of thrust per kilowatt, compared with a jet engine's 2 newtons per kilowatt. The team has published its results in the Proceedings of the Royal Society.

Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, envisions that ionic wind may be used as a propulsion system for small, lightweight aircraft. In addition to their relatively high efficiency, ionic thrusters are silent, and invisible in infrared, as they give off no heat — ideal traits, he says, for a surveillance vehicle.

"You could imagine all sorts of military or security benefits to having a silent propulsion system with no infrared signature," says Barrett, who co-authored the paper with graduate student Kento Masuyama.

Shooting the gap

A basic ionic thruster consists of three parts: a very thin copper electrode, called an emitter; a thicker tube of aluminum, known as a collector; and the air gap in between. A lightweight frame typically supports the wires, which connect to an electrical power source. As voltage is applied, the field gradient strips away electrons from nearby air molecules. These newly ionized molecules are strongly repelled by the corona wire, and strongly attracted to the collector. As this cloud of ions moves toward the collector, it collides with surrounding neutral air molecules, pushing them along and creating a wind, or thrust.

To measure an ion thruster's efficiency, Barrett and Masuyama built a similarly simple setup, and hung the contraption under a suspended digital scale. They applied tens of thousands of volts, creating enough current draw to power an incandescent light bulb. They altered the distance between the electrodes, and recorded the thrust as the device lifted off the ground. Barrett says that the device was most efficient at producing lower thrust — a desirable, albeit counterintuitive, result.

"It's kind of surprising, but if you have a high-velocity jet, you leave in your wake a load of wasted kinetic energy," Barrett explains. "So you want as low-velocity a jet as you can, while still producing enough thrust." He adds that an ionic wind is a good way to produce a low-velocity jet over a large area.

Getting to liftoff

Barrett acknowledges that there is one big obstacle to ionic wind propulsion: thrust density, or the amount of thrust produced per given area. Ionic thrusters depend on the wind produced between electrodes; the larger the space between electrodes, the stronger the thrust produced. That means lifting a small aircraft and its electrical power supply would require a very large air gap. Barrett envisions that electrodynamic thrusters for aircraft — if they worked — would encompass the entire vehicle.

Another drawback is the voltage needed to get a vehicle off the ground: Small, lightweight balsa models require several kilovolts. Barrett estimates a small craft, with onboard instrumentation and a power supply, would need hundreds or thousands of kilovolts.

"The voltages could get enormous," Barrett says. "But I think that's a challenge that's probably solvable." For example, he says power might be supplied by lightweight solar panels or fuel cells. Barrett says ionic thrusters might also prove useful in quieter cooling systems for laptops.

"Efficiency is probably the number one thing overall that drives aircraft design," Barrett says."[Ionic thrusters] are viable insofar as they are efficient. There are still unanswered questions, but because they seem so efficient, it's definitely worth investigating further." ### Written by Jennifer Chu, MIT News Office END


ELSE PRESS RELEASES FROM THIS DATE:

Diversity programs give illusion of corporate fairness, study shows

2013-04-03
Diversity training programs lead people to believe that work environments are fair even when given evidence of hiring, promotion or salary inequities, according to new findings by psychologists at the University of Washington and other universities. The study also revealed that participants, all of whom were white, were less likely to take discrimination complaints seriously against companies who had diversity programs. Workplace diversity programs are usually developed by human resource departments to foster a more inclusive environment for employees, but aren't typically ...

Invasive crabs help Cape Cod marshes

2013-04-03
PROVIDENCE, R.I. [Brown University] — Long vilified, invasive species can sometimes become an ecosystem asset. New Brown University research published online in the journal Ecology reports exactly such a situation in the distressed salt marshes of Cape Cod. There, the invasive green crab Carcinus maenas is helping to restore the marsh by driving away the Sesarma reticulatum crabs that have been depleting the marsh grasses. The observations and experiments of the research show that the green crab has filled the void left by the decline of native predators of sesarma crabs, ...

New relief for gynecological disorders

2013-04-03
The creation of new blood vessels in the body, called "angiogenesis," is usually discussed in connection with healing wounds and tumors. But it's also an ongoing process in the female reproductive tract, where the growth and breaking of blood vessels is a normal part of the menstrual cycle. But abnormal growth of blood vessels can have painful consequences and resultant pathologies. Now, Prof. Ruth Shalgi and research associate Dr. Dana Chuderland of Tel Aviv University's Sackler Faculty of Medicine have found a potential treatment for this abnormal growth in a potent ...

Gender bias found in how scholars review scientific studies

2013-04-03
COLUMBUS, Ohio – A scientist's gender can have a big impact on how other researchers perceive his or her work, according to a new study. Young scholars rated publications supposedly written by male scientists as higher quality than identical work identified with female authors. The research found that graduate students in communication -- both men and women -- showed significant bias against study abstracts they read whose authors had female names like "Brenda Collins" or "Melissa Jordan." These students gave higher ratings to the exact same abstracts when the authors ...

Breakthrough cancer-killing treatment has no side-effects

2013-04-03
Cancer painfully ends more than 500,000 lives in the United States each year, according to the Centers for Disease Control and Prevention. The scientific crusade against cancer recently achieved a victory under the leadership of University of Missouri Curators' Professor M. Frederick Hawthorne. Hawthorne's team has developed a new form of radiation therapy that successfully put cancer into remission in mice. This innovative treatment produced none of the harmful side-effects of conventional chemo and radiation cancer therapies. Clinical trials in humans could begin soon ...

Study: Environmental policies matter for growing megacities

2013-04-03
WEST LAFAYETTE, Ind. – A new study shows clean-air regulations have dramatically reduced acid rain in the United States, Europe, Japan and South Korea over the past 30 years, but the opposite is true in fast-growing East Asian megacities, possibly due to lax antipollution rules or lack of enforcement. The U.S. Clean Air Act began requiring regulatory controls for vehicle emissions in the 1970s, and 1990 amendments addressed issues including acid rain. Similar steps in the European Union, Japan and South Korea over the past three decades have reduced nitrate and sulfate ...

UCLA brain-imaging tool and stroke risk test help identify cognitive decline early

2013-04-03
UCLA researchers have used a brain-imaging tool and stroke risk assessment to identify signs of cognitive decline early on in individuals who don't yet show symptoms of dementia. The connection between stroke risk and cognitive decline has been well established by previous research. Individuals with higher stroke risk, as measured by factors like high blood pressure, have traditionally performed worse on tests of memory, attention and abstract reasoning. The current small study demonstrated that not only stroke risk, but also the burden of plaques and tangles, as ...

Shape from sound: New methods to probe the universe

2013-04-03
As the universe expands, it is continually subjected to energy shifts, or "quantum fluctuations," that send out little pulses of "sound" into the fabric of spacetime. In fact, the universe is thought to have sprung from just such an energy shift. A recent paper in the journal Physical Review Letters reports a new mathematical tool that should allow one to use these sounds to help reveal the shape of the universe. The authors reconsider an old question in spectral geometry that asks, roughly, to what extent can the shape of a thing be known from the sound of its acoustic ...

HIV self-testing: The key to controlling the global epidemic

2013-04-03
This press release is available in French. AUDIO: Dr. Nitika Pan Pai, researcher at the RI-MUHC and professor at McGill University (Montreal, Canada) talks about HIV Self-testing as a key to control the global epidemic. Click here for more information. Montreal, April 3, 2013 – A new international study has confirmed that self-testing for HIV is effective and could be the answer to controlling the ...

Can synthetic biology save wildlife?

2013-04-03
What effects will the rapidly growing field of synthetic biology have on the conservation of nature? The ecological and ethical challenges stemming from this question will require a new dialogue between members of the synthetic biology and biodiversity conservation communities, say Kent Redford of the Wildlife Conservation Society (WCS) and Archipelago Consulting; Bill Adams of the University of Cambridge; and Georgina Mace of University College London (UCL) in a new paper published 2 April in the open access journal PLOS Biology. The field of synthetic biology—a discipline ...

LAST 30 PRESS RELEASES:

Older teens who start vaping post-high school risk rapid progress to frequent use

Corpse flowers are threatened by spotty recordkeeping

Riding the AI wave toward rapid, precise ocean simulations

Are lifetimes of big appliances really shrinking?

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

[Press-News.org] Study finds ionic thrusters generate efficient propulsion in air
Thrusters powered by ionic wind may be an efficient alternative to conventional atmospheric propulsion technologies