What causes ionic wind?

February 7, 2018 by Lisa Zyga, Phys.org feature
(Top left) Image of the plasma jet in continuous mode and (bottom left) composite image of nanosecond-resolved images. (Right) Schlieren photography images of the trajectory of gas flow with and without a plasma jet. Credit: Park et al. Published in Nature Communications

The phenomenon of ionic wind has been known about for centuries: by applying a voltage to a pair of electrodes, electrons are stripped off nearby air molecules, and the ionized air collides with neutral air molecules as it moves from one electrode to the other. The effect is easy enough to produce that it often appears at science fairs, and may even have a future in spacecraft propulsion. However, exactly what causes ionic wind is still an open question.

In a new paper published in Nature Communications, a team of researchers from South Korea and Slovenia has experimentally investigated how ionic wind is caused when collide with . One of their main findings is that electrons—and not only ions—play an important role in generating ionic wind, prompting them to call the effect "electric wind."

"In general, the electric wind has been called an 'ionic wind' because only the positive and have been considered as key players," coauthor Wonho Choe, Professor at the Korea Advanced Institute of Science and Technology, told Phys.org. "In our study, however, both electrons and ions participate in the generation of electric wind, depending on the polarity of the biased electrode. So the use of nomenclature for the 'ionic wind' requires a new consensus. We use the term 'electric wind' instead of ',' as our key finding indicates that electrons are the main player rather than negative ions such as O2- and O- during the negative voltage period."

In their experiments, the researchers generated a neutral helium flow and a pulsed jet at various voltages. Then they used a technique called Schlieren photography (which is often used to photograph airplanes in flight) to take pictures of the flows of these particles. By controlling the pulse width and height of the , the researchers monitored how these changes affect the particles' movement and the resulting wind.

As this is the first experiment to clearly show the coupling between neutral and charged particles in a plasma, the results provide direct evidence of what happens as the electrons and ions push the neutral particles away. The resulting momentum transfer causes a charged particle drag, which generates an electrohydrodynamic force (one caused by charged particles), giving rise to a clearly observable wind of charged particles.

"The electric wind was previously considered to be a result of collisional momentum transfer from accelerated charged particles and neutral particles, based on heuristic observations and experiments," Choe said. "However, as mentioned in our paper, there was no convincing evidence regarding the major mechanism (the correlation between plasma and momentum transfer) for the generation of electric wind, which is created during either the 'streamer propagation (ionization wave)' or the 'space charge drift.' Our model experiments clearly show that the contribution of the moving plasma streamer to electric wind generation is negligible, and the electric wind is mainly caused by the residual space charges after the plasma streamer propagates and collapses."

The results should lead to a better understanding of the interactions between charged and neutral in various situations, and has potential applications in areas such as flow control engineering.

"Our findings may have applications for reducing the drag force on a vehicle, resulting in the reduction of fuel consumption and nitrogen oxides, which are an environmental pollutant and one of the major sources of micro dusts," Choe said. "It may also reduce flow separation on wind turbine blades."

The researchers also plan to investigate potential applications with plasmas.

"One of the recent interesting topics in the plasma community is the selective control of chemical production by low-temperature air plasmas," Choe said. "We have planned research to study a correlation between plasma chemicals and electric wind. We may also investigate the possible correlation between the electric and the plasma ball, a phenomenon that can occur when lightning strikes."

Explore further: The stability of the solar wind

More information: Sanghoo Park, Uros Cvelbar, Wonho Choe, and Se Youn Moon. "The creation of electric wind due to the electrohydrodynamic force." Nature Communications. DOI: 10.1038/s41467-017-02766-9

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Display comments: newest first

rossim22
1.4 / 5 (9) Feb 07, 2018
And the general consensus is still that a comet's tail is formed from sublimation of ad hoc interior ice. smh
barakn
4.5 / 5 (8) Feb 07, 2018
You have a lot to learn, starting with the fact that comets typically have more than one tail.
Captain Stumpy
4 / 5 (8) Feb 07, 2018
You have a lot to learn, starting with the fact that comets typically have more than one tail.

I'm actually surprised that the electric cow cult isn't being udderly ridiculous in this thread...

in before the eu bull

cantdrive85
1.4 / 5 (9) Feb 07, 2018
However, exactly what causes ionic wind is still an open question.

It's amusing that those who deny all which is electric are so sure of themselves when there seems to be a lack of understanding of mechanisms such as this phenomenon.
RealityCheck
1.7 / 5 (6) Feb 07, 2018
From above article/work:
One of their main findings is that electrons—and not only ions—play an important role in generating ionic wind, prompting them to call the effect "electric wind
and
We use the term 'electric wind' instead of 'ionic wind,' as our key finding indicates that electrons are the main player
and
this is the first experiment to clearly show the coupling between neutral and charged particles in a plasma
and
results should lead to a better understanding of the interactions between charged and neutral particles in various situations
and
possible correlation between the electric wind and the plasma ball
@cantdrive (and @Stumpy if reading), mainstream is really 'getting into' investigating all the plasma fast-electron/neutrals etc behaviors/structures previously pointed out to 'the gang' who ridiculed instead of listening/learning earlier. It is to be hoped that 'the gang' can read/understand the above, then THINK instead of INSULT. :)
Captain Stumpy
3.7 / 5 (6) Feb 07, 2018
@idiot pseudoscience delusional quack fodera-head with a criminal record
(and @Stumpy if reading)
you know I never read your posts

no links, references = bullsh*t pseudoscience

and you have been proving that for 7,655 posts (accurate as of February 7, 2018, 5:16 pm)
RealityCheck
1.7 / 5 (6) Feb 07, 2018
@Stumpy.
@idiot pseudoscience delusional quack fodera-head with a criminal record
You tried that blatant lie last year, mate; and you were called out on it. Anyone can (and have) checked out for themselves and found me to have NO 'criminal record' as you keep stating in your desperation. If that is not PROOF of your personal feuding agenda/tactics INSTEAD of fair objective on-science discourse, then what is?

Why do this to yourself, Stumpy?
(and @Stumpy if reading)
you know I never read your posts
Which is why you end up with egg-on-face almost every day now, as new mainstream science discovery/review work/reports appear, confirming me correct all along; while your own bile is inexorably poisoning what's left of whatever 'little grey cells' quotient you may have started out with.

Why do this to yourself, Stumpy?

Try to be a better man and scientist this new year, Stumpy. First step: Drop the bile/ego/lies and personal feuding agenda/tactics. Good luck. :)
691Boat
4.6 / 5 (11) Feb 07, 2018
@RC:
if you want to stop the feuding between you and everyone else, quit acknowledging what you see as an attack and move on. Nobody cares if you feeling got hurt, but I can promise you that even fewer people want to read about it.

And if you really want to link this to EU bull, show me in their theories/maths/proofs where they had already predicted all this. Your claim that this has been pointed out by 'the gang' numerous times is pointless with no actual proof besides what some cranks posted in a comment section somewhere at some point in the past.
cantdrive85
1 / 5 (5) Feb 08, 2018

You can be sure the "electric wind" as described above has been in the lexical well since early on in the development of the EU theory about 20-years-ago.
Here it is described as electrokinesis as it relates to how the electric wind drives thunderstorms.
"The drift region of a corona creates unipolar winds as drifting electrons drag ions and neutral matter along by electrokinesis."
https://www.thund...rmopile/
Looks like electrical engineers are more relevant to the atmospheric sciences than atmospheric scientists are...
691Boat
4.4 / 5 (7) Feb 08, 2018
@CD:
The link you supplied to a pseudo-science blog is considered proof for "electric wind" and how it relates to EU? neato. Any youtube videos to really convince me?
jonesdave
4.4 / 5 (7) Feb 08, 2018
And the general consensus is still that a comet's tail is formed from sublimation of ad hoc interior ice. smh


Not good on research are you Rossim? Remember Tempel 1 in 2005? Only 12.5 years ago, so I suppose we can forgive you for not being up to date! Why was ice (yes, solid grains) blasted out of the comet by the impact? Sure as hell wasn't sitting around on the surface, as the images showed.
And if you haven't bothered to read the literature on that mission, there is no chance you are up with the findings at Hartley 2 in 2010. Dirty great chunks of ice, blasted out by CO2 jets. There were some very pretty pictures, including on this site: https://phys.org/...met.html
Then there is the more recent Rosetta mission to 67P. Boulders of ice just lying around beneath cliffs. Before it was an icy boulder, where do you think it was? You woo types really should learn some research skills.
RealityCheck
1 / 5 (4) Feb 08, 2018
@691Boat.

Because you seem NOT to be part of 'that gang', I'll point out certain things you may have missed that led you to make such dangerously naive/erroneous statements/advice as:
if you want to stop the feuding between you and everyone else,
You just made an erroneous "everyone else" generalization which ignores the patent fact it's ONLY CS and 'his gang/friends' who keep attacking ME; forcing ME to DEFEND...ON PRINCIPLE.
quit acknowledging what you see as an attack and move on. Nobody cares if you feeling got hurt,....
It's not about my 'personal feelings being hurt'; but their BLATANT BETRAYAL of ALL objective/fair Science/Humanity PRINCIPLES.

@691Boat, would YOU be so 'sanguine' if CS/gang kept:

- LYING (ie: that YOU had a "criminal record");

- TROLLING, DISPARAGING. BOT-VOTING against YOU (even when YOU were CORRECT on science/logics (see my climate science posts BOT-voted '1' by CS/Ira/gang, against all objective/fair play PRINCIPLES)?

PRINCIPLES. :)
RealityCheck
1 / 5 (4) Feb 08, 2018
PS @691Boat:
And if you really want to link this to EU bull, show me in their theories/maths/proofs where they had already predicted all this. Your claim that this has been pointed out by 'the gang' numerous times is pointless with no actual proof besides what some cranks posted in a comment section somewhere at some point in the past.
I remind you/everyone that THE OBJECTIVE SCIENTIFIC METHOD was invented for the express purpose of REMOVING/AVOIDING PERSONAL/SUBJECTIVE HUMAN prejudices/foibles from what should be SCRUPULOUSLY OBJECTIVE scientific enquiry/discourse.

I try to stick to the IDEA/ARGUMENT ITSELF, irrespective of 'who presents' it; keeping to the ACTUAL scientific point/suggestion under discussion irrespective of 'origins'; ignoring ALL ELSE attributed to said 'source'.

Eg: I pointed out mainstream science 'catching up with' and studying/experimenting/acknowledging SOME things long pointed out by @cantdrive et al.

Ie, FAIRNESS/OBJECTIVITY in ACTION! :)
691Boat
4.3 / 5 (6) Feb 09, 2018
@RC:
It is a science website comment section, so no, I would not care if someone called me a liar. I probably wouldn't be upset if someone kept calling me a plasma ignoramus either. Grow a pair.

So, if I come up with some random theory that hasn't been very well explored yet in any regard, whether it is direct or indirect study, but some researchers perform some work that can be considered similar to my pretend theory (even though it doesn't work), I can then claim that anything that has a keyword or phrase in it is directly related to my new made up theory? That's neat!
RealityCheck
1 / 5 (5) Feb 09, 2018
@691Boat.
It is a science website comment section, so no, I would not care if someone called me a liar. I probably wouldn't be upset if someone kept calling me a plasma ignoramus either.
Please read properly before again making mistaken assertions/advice, mate. It was ME called CS a liar; because CS falsely accuses me of having a "criminal record". Why did you not even understand/address THAT?

Please answer:

Would YOU be so sanguine if CS KEPT ON FALSELY accusing YOU of having a "criminal record", @691Boat?
but some researchers perform some work that can be considered similar to my pretend theory (even though it doesn't work)
You've been around CS/gang too long; and 'caught' CS/gang 'disease'! Your above fantasy-based rationalizations/characterizations fly in the face of REALITY. There's nothing "random" about my REALITY-BASED ToE/Maths work/insight; and these are being confirmed correct BY MAINSTREAM, NOW, despite CS/gang deny-lie-campaign you've 'swallowed'. :)
691Boat
5 / 5 (4) Feb 12, 2018
@RC:
Again, it is a comment section on a science reporting website. Get over it and move on.
jonesdave
5 / 5 (4) Feb 12, 2018
What causes ionic wind?


Ionic beans would be my guess.
RealityCheck
1 / 5 (3) Feb 13, 2018
@691Boat.
Again, it is a comment section on a science reporting website. Get over it and move on.
Is that your advice to everyone attacked by a psychopathic perpetrator of abuse (whatever form that abuse takes)? Why put the onus on the VICTIM of abuse, mate? It's that kind of unwitting 'enabling' cop-out that had allowed all those decades of child sexual abuse, domestic violence and abuse of power in industry/govts where the victims were effectively ignored/silenced precisely because of such 'attitudes' as yours above, mate. It's only NOW when victims speaking up and heard/treated with respect that all the 'hidden' abuses/perpetrators exposed.

NB:

"For evil to flourish, it is sufficient that good men/women do nothing".

That is effectively your advise/response, @Boat!

Anyhow, @Boat:

- Why don't you tell the perpetrator "to move on", instead of the victim?

- Would YOU be so sanguine if CS KEPT ON FALSELY accusing YOU of having a "criminal record"?

Answers?
RealityCheck
1 / 5 (2) Feb 13, 2018
@jonesdave.
What causes ionic wind?
Ionic beans would be my guess.
You miss the REALITY of what's going down, mate. :)

Please read my first post above. See that the above article/study recognizes that it's the LIGHTER/FASTER (than 'ions') ELECTRONS that play the greatest role in these 'winds' phenomena. That is why they NOW CORRECTLY prefer to call it "ELECTRIC WIND".

These faster electron effects/currents are always a major part of the plasma flows/dynamics; and its these 'electric winds' that create/constitute the electric currents; which arise/fluctuate and subside in, across, along, all plasma flows/features. And it's this sort of 'charge-self-sorting' dynamics/processes that create transient/persistent stellar/galactic VOLTAGE conditions which then drive further electric/ion 'currents'.

ps @691Boat: for more insights into GALACTIC SCALE voltages/currents/effects, also read up on Galactic HOMOPOLAR GENERATOR phenomena/feature.

End the feuding. :)
RealityCheck
1 / 5 (2) Feb 13, 2018
pps @jonesy: No, I didn't miss the humorous "ionic beaNs" causing "ionic wind" joke, mate. Just so you know I have a sense of humor too.

End the feuding. Cheers. :)
691Boat
5 / 5 (3) Feb 14, 2018
@RC:
Here is what I read:
"oh no! my fake name is being slandered! Now nobody in the professional world will take me seriously! My feelings are hurt now, because everyone from any respected journal and scientific institution know me only as "RealityCheck." That's why your complaints are pointless.

In summary, you are complaining because an alias is slandering your alias amongst a comment section full of aliases.
RealityCheck
1 / 5 (3) Feb 14, 2018
@691Boat.
Here is what I read:
"oh no! my fake name is being slandered! Now nobody in the professional world will take me seriously! My feelings are hurt now, because everyone from any respected journal and scientific institution know me only as "RealityCheck." That's why your complaints are pointless.

In summary, you are complaining because an alias is slandering your alias amongst a comment section full of aliases.
Unfrtunately, your "read" is as mistaken as your "advice", @691Boat.

If you'd been reading @Stumpy's malignant campaign of lying, insulting posts, you would have noted @Stumpy has used my REAL name.

Do YOU have @Stumpy on "IGNORE"?....If so, it indicates your discernment and judgement of the 'negative value' of @Stumpy's posts!...Else you would have known that @Stumpy has been using my REAL name; and would not have made the above mistaken "read".

In any case, a NOM DE PLUME MAY BE a VALUABLE ASSET/IDENTITY (not in @Stumpy's case, obviously). :)
RealityCheck
1 / 5 (2) Feb 14, 2018
ps @691Boat and @jonesdave.

Back to science.

@691Boat: Did you read up artificial/natural "Homopolar Generator" systems? It will help you realize the many possible ways that 'voltages' and 'electric currents' CAN arise, reinforce, subside in many man-made and astrophysical situations involving plasma/electron dynamics at many scales. Good luck, good "reading" and good thinking, mate. )

@jonesdave: Try to avoid the feuding; just concentrate on getting up to speed with all the plasma/electric current dynamics being 'discovered' by mainstream, re-interpreting past (incorrect) interpretations as to what is happening in REALITY in the many plasma/electron dynamics found at all scales.

LATEST NEWS:

https://phys.org/...rgy.html

NB: ELECTRIC CURRENTS now being increasingly acknowledged in all the astrophysical processes/circuits etc inevitably involving plasma/fast-electron currents/pinches etc.

End the feuds. Cheers all. :)

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