374:) means that the moving particles diffuse into an expanding ion cloud, and collide frequently with neutral air molecules. It is these collisions that create thrust. The momentum of the ion cloud is partially imparted onto the neutral air molecules that it collides with, which, because they are neutral, do not migrate back to the second electrode. Instead they continue to travel in the same direction, creating a neutral wind. As these neutral molecules are ejected from the ionocraft, there are, in agreement with
414:
378:, equal and opposite forces, so the ionocraft moves in the opposite direction with an equal force. The force exerted is comparable to a gentle breeze. The resulting thrust depends on other external factors including air pressure and temperature, gas composition, voltage, humidity, and air gap distance.
485:
The collector is shaped to provide a smooth equipotential surface underneath the corona wire. Variations of this include a wire mesh, parallel conductive tubes, or a foil skirt with a smooth, round edge. Sharp edges on the skirt degrade performance, as it generates ions of opposite polarity to those
421:
The thrust generating components of an ion propulsion system consist of three parts; a corona or emitter wire, an air gap and a collector wire or strip downstream from the emitter. A lightweight insulating frame supports the arrangement. The emitter and collector should be as close to each other as
219:
The effect is not directly dependent on electrical polarity, as the ions may be positively or negatively charged. Reversing the polarity of the electrodes does not alter the direction of motion, as it also reverses the polarity of the ions carrying charge. Thrust is produced in the same direction,
385:
is impacted repeatedly by excited particles moving at high drift velocity. This creates electrical resistance, which must be overcome. The result of the neutral air caught in the process is to effectively cause an exchange in momentum and thus generate thrust. The heavier and denser the air, the
153:
Twenty-first century power supplies are lighter and more efficient. The first ion-propelled aircraft to take off and fly using its own onboard power supply was a VTOL craft developed by Ethan Krauss of
Electron Air in 2006. His patent application was filed in 2014, and he was awarded a
476:
The air gap insulates the two electrodes and allows the ions generated at the emitter to accelerate and transfer momentum to neutral air molecules, before losing their charge at the collector. The width of the air gap is typically 1 mm / kV.
125:
in the 1950s and 1960s. He filed a patent for an "ionocraft" in 1959. He built and flew a model VTOL ionocraft capable of sideways manoeuvring by varying the voltages applied in different areas, although the heavy power supply remained external.
354:
from them. As this happens, the ions are repelled from the anode and attracted towards the collector, causing the majority of the ions to accelerate toward the collector. These ions travel at a constant average velocity termed the
224:
ions are created initially, while for negative polarity, oxygen ions are the major primary ions. Both these types of ion immediately attract a variety of air molecules to create molecular cluster-ions of either sign, which act as
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tends to outperform more common, larger sizes such as 30 gauge, as the stronger electric field around the smaller diameter wire results in lower ionisation onset voltage and a larger corona current as described by
1207:
330:
is the ion mobility of the working fluid, measured in A s kg in SI units, but more commonly described in units of m V s A typical value for air at surface pressure and temperature is 1.5Ă—10
111:. Since his devices produced thrust in the direction of the field gradient, regardless of the direction of gravity, and did not work in a vacuum, other workers realized that the effect was due to EHD.
232:
Current EHD thrusters are far less efficient than conventional engines. An MIT researcher noted that ion thrusters have the potential to be far more efficient than conventional jet engines.
422:
possible, i.e. with a narrow air gap, to achieve a saturated corona current condition that produces maximum thrust. However, if the emitter is too close to the collector it tends to
173:. It had a 5-meter wingspan and weighed 2.45 kg. The craft was catapult-launched using an elastic band, with the EAD system sustaining the aircraft in flight at low level.
303:
1202:
118:, This was insufficient to lift the heavy high-voltage power supply necessary, which remained on the ground and supplied the craft via long, thin and flexible wires.
662:
Roy, Subrata; Arnold, David; Lin, Jenshan; Schmidt, Tony; Lind, Rick; et al. (2011). Air Force Office of
Scientific Research; University of Florida (eds.).
952:
783:
191:, without any moving parts. Because of this it is sometimes described as a "solid-state" drive. It is based on the principle of electrohydrodynamics.
495:
940:…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…
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The emitter wire is typically connected to the positive terminal of the high voltage power supply. In general, it is made from a small gauge bare
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896:
170:
130:
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1184:
813:
712:
Granados, Victor H.; Pinheiro, Mario J.; Sa, Paulo A. (July 2016). "Electrostatic propulsion device for aerodynamics applications".
678:
122:
133:(WEAV), a saucer-shaped EHD lifter with electrodes embedded throughout its surface, was studied by a team of researchers led by
1289:
1117:
Tajmar, M. (2000). "Experimental investigation of 5-D divergent currents as a gravity-electromagnetism coupling concept".
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114:
VTOL ion-propelled aircraft are sometimes called "lifters". Early examples were able to lift about a gram of weight per
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in the early part of the twenty-first century. The propulsion system employed many innovations, including the use of
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in reaction. Along the way, these ions collide with electrically neutral air molecules and accelerate them in turn.
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between collisions, the strength of the external electric field, and the mass of ions and neutral air molecules.
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The flying device originally lifted its power supply directly off of the ground with no moving parts in 2006.
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to enhance the ionisation efficiency. A model with an external supply achieved minimal lift-off and hover.
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in 2017. The craft developed enough thrust to rise rapidly or to fly horizontally for several minutes.
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The emitter is sometimes referred to as the "corona wire" because of its tendency to emit a purple
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346:. When the corona wire reaches approximately 30 kV, it causes the air molecules nearby to become
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As applied to a gas such as air, the principle is also referred to as electroaerodynamics (EAD).
204:, a leading emitter wire and a downstream collector. When such an arrangement is powered by high
1146:
Tajmar, M. (February 2004). "Biefeld-Brown Effect: Misinterpretation of Corona Wind
Phenomena".
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As with conventional reaction thrust, EAD thrust may be directed either horizontally to power a
696:"Full analysis & design solutions for EHD Thrusters at saturated corona current conditions"
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spent much of his life working on the principle, under the mistaken impression that it was an
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Ion propulsion systems require many safety precautions due to the required high voltage.
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Tajmar, M. (2004). "Biefeld–Brown Effect: Misinterpretation of Corona Wind
Phenomena".
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flew 60 meters. It was developed by a team of students led by Steven
Barrett from the
58:. Current designs do not produce sufficient thrust for manned flight or useful loads.
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The use of EHD propulsion for lift was studied by
American aircraft designer Major
104:
55:
43:
20:
1185:
Exploratory
Research on the Phenomenon of the Movement of High Voltage Capacitors
165:
In
November 2018 the first self-contained ion-propelled fixed-wing airplane, the
80:
19:
This article is about ion propelled aircraft. For ion propelled spacecraft, see
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Tammet, H. (1998). "Reduction of air ion mobility to standard conditions".
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molecules in the air that accelerate backwards to the collector, producing
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79:-generated charged particles was discovered soon after the discovery of
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When the ionocraft is turned on, the corona wire becomes charged with
445:
213:
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580:
897:"Silent and Simple Ion Engine Powers a Plane with No Moving Parts"
412:
1227:
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632:. Vol. 122. Popular mechanics. August 1964. pp. 58–61.
441:
115:
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glow while in use. This is simply a side effect of ionization.
347:
265:. A generalized one-dimensional treatment gives the equation:
645:"The World's First Flying Saucer: Made Right Here on Earth"
257:
The thrust generated by an EHD device is an example of the
1203:
The
Biefeld Brown Effect and the Global Electric Circuit
664:
Demonstration of a
Wingless Electromagnetic Air Vehicle
922:"Ionic thrusters generate efficient propulsion in air"
840:"Ion-aerosol-cloud processes in the lower atmosphere"
273:
1071:
Meesters, Koos; Terpstra, Wessel (2 December 2019).
814:"First ever plane with no moving parts takes flight"
297:
187:is a technique for creating a flow of air through
85:Physico-Mechanical Experiments on Various Subjects
1241:"NASA – Ion Propulsion: Farther, Faster, Cheaper"
261:and can be derived through a modified use of the
243:principle does not apply in the vacuum of space.
1050:Dielectric Phenomena in High Voltage Engineering
669:(Report). Defense Technical Information Center.
208:(in the range of kilovolts per mm), the emitter
83:with references dating to 1709 in a book titled
617:, Filed Aug 31 1959, Published April 28, 1954.
448:wire can be used, it does not work as well as
596:"J L Naudin’s Lifter-3 pulsed HV 1.13g/Watt"
8:
1234:NASA: Asymmetrical Capacitors for Propulsion
1005:Journal of Geophysical Research: Atmospheres
405:craft, sometimes referred to as a "lifter".
452:. Similarly, thinner wire such as 44 or 50
629:Major de Seversky's Ion-Propelled Aircraft
594:Lifter efficiency relation to ion velocity
366:The fact that the current is carried by a
1032:
863:
280:
272:
1104:. Defense Technical Information Center.
496:Atmosphere-breathing electric propulsion
1265:How to Make/Build a Lifter or Ionocraft
1102:Twenty First Century Propulsion Concept
532:
16:Electrohydrodynamic aircraft propulsion
1194:Asymmetrical Capacitors for Propulsion
702:(non-peer-review), 2004, Updated 2006.
194:In its basic form, it consists of two
1230:'s "Common Errors in propulsion" page
998:
996:
745:
743:
171:Massachusetts Institute of Technology
7:
1206:. AIP Conference Proceedings, 2005.
381:The air mass in the gap between the
131:Wingless Electromagnetic Air Vehicle
643:Greenemeier, Larry (7 July 2008).
14:
684:from the original on 17 May 2013.
298:{\displaystyle F={\frac {Id}{k}}}
220:either way. For positive corona,
1191:FX Canning, C Melcher, E Winet,
751:"Ion-Powered Aircraft Invention"
123:Alexander Prokofieff de Seversky
1188:. Journal of Space Mixing, 2004
1073:"ion drives and sustainability"
977:"Electrokinetic devices in air"
812:Hern, Alex (21 November 2018).
540:Thompson, Clive (August 2003).
359:. Such velocity depends on the
1100:Talley, Robert L. (May 1991).
417:Typical ionocraft construction
1:
542:"The Antigravity Underground"
516:Magnetoplasmadynamic thruster
486:within the thrust mechanism.
386:higher the resulting thrust.
50:in the air without requiring
755:The Stardust-Startup Factory
677:. AFRL-OSR-VA-TR-2012-0922.
376:Newton's Third Law of Motion
370:(and not a tightly confined
342:, usually between 20 and 50
700:The General Science Journal
401:or vertically to support a
107:effect, which he named the
1316:
1119:AIP Conference Proceedings
250:
167:MIT EAD Airframe Version 2
158:to support his project by
18:
1224:Electrostatic Antigravity
95:VTOL "lifter" experiments
838:Harrison, R. G. (2003).
318:is the electric current.
312:is the resulting force.
263:Child–Langmuir equation
177:Principles of operation
418:
390:Aircraft configuration
299:
99:American experimenter
28:ion-propelled aircraft
844:Reviews of Geophysics
614:U.S. patent 3,130,945
416:
300:
139:University of Florida
101:Thomas Townsend Brown
1290:Electrostatic motors
1011:(D12): 13933–13937.
865:10.1029/2002rg000114
506:Hall-effect thruster
501:Biefeld–Brown effect
271:
259:Biefeld–Brown effect
253:Electrohydrodynamics
247:Electrohydrodynamics
109:Biefeld–Brown effect
40:electrohydrodynamics
1300:American inventions
1251:on 11 November 2020
1160:2004AIAAJ..42..315T
1131:2000AIPC..504..998T
1048:Peek, F.W. (1929).
1017:1998JGR...10313933T
901:Scientific American
856:2003RvGeo..41.1012H
726:2016PhPl...23g3514G
649:Scientific American
573:2004AIAAJ..42..315T
350:by stripping their
241:electrohydrodynamic
1210:2022-05-08 at the
757:. 27 February 2019
714:Physics of Plasmas
600:2014-08-08 at the
419:
295:
1285:Electric aircraft
1239:DeFelice, David.
1139:10.1063/1.1290898
1125:. AIP: 998–1003.
1025:10.1029/97JD01429
734:10.1063/1.4958815
331:m V s).
293:
189:electrical energy
160:Stardust Startups
71:The principle of
42:(EHD) to provide
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953:"Ion Propulsion"
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89:Francis Hauksbee
75:propulsion with
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1253:. Retrieved
1249:the original
1245:www.nasa.gov
1244:
1201:
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1182:DR Buehler,
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1148:AIAA Journal
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1079:. Retrieved
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983:. Retrieved
971:
960:the original
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932:. Retrieved
927:ScienceDaily
925:
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904:. Retrieved
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821:. Retrieved
818:the Guardian
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759:. Retrieved
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561:AIAA Journal
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511:Ion thruster
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403:powered lift
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340:high voltage
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237:ion thruster
235:Unlike pure
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105:anti-gravity
98:
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70:
56:moving parts
31:
27:
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21:Ion thruster
1034:10062/50224
850:(3): 1012.
823:25 November
780:us 10119527
135:Subrata Roy
81:electricity
1295:Propulsion
1279:Categories
1081:3 December
675:B01IKW9SES
527:References
459:Peek's law
439:conductive
396:fixed-wing
383:electrodes
202:electrodes
199:conductive
156:microgrant
73:ionic wind
52:combustion
38:that uses
1255:15 August
1176:0001-1452
1110:227770672
906:15 August
882:123305218
874:8755-1209
761:15 August
481:Collector
352:electrons
129:The 2008
32:ionocraft
1208:Archived
1058:30000280
985:25 April
934:14 March
679:Archived
598:Archived
490:See also
444:. While
399:airplane
222:nitrogen
196:parallel
36:aircraft
1270:YouTube
1197:. 2004.
1156:Bibcode
1127:Bibcode
1013:Bibcode
852:Bibcode
801:YouTube
722:Bibcode
569:Bibcode
472:Air gap
433:Emitter
348:ionised
210:ionizes
206:voltage
137:at the
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