Editing Magnetohydrodynamic drive (section)

==== Prospects ====
MHD propulsion has been considered as the main propulsion system for both marine and space ships since there is no need to produce lift to counter the [[gravity of Earth]] in water (due to [[buoyancy]]) nor in space (due to [[weightlessness]]), which is ruled out in the case of [[flight]] in the [[atmosphere]].

Nonetheless, considering the current problem of the [[Electric power|electric power source]] solved (for example with the availability of a still missing multi-megawatt compact [[Fusion power|fusion reactor]]), one could imagine future aircraft of a new kind silently powered by MHD accelerators, able to ionize and direct enough air downward to lift several [[tonne]]s. As external flow systems can control the flow over the whole wetted area, limiting thermal issues at high speeds, ambient air would be ionized and radially accelerated by Lorentz forces around an [[Rotational symmetry#Rotational symmetry with respect to any angle|axisymmetric]] body (shaped as a [[cylinder]], a [[cone]], a [[sphere]]...), the entire [[airframe]] being the engine. Lift and thrust would arise as a consequence of a [[pressure]] difference between the upper and lower surfaces, induced by the [[Coandă effect]].<ref name='"Coanda patent">{{cite patent
 |country=US
 |number=2108652
 |status=patent
 |title=Propelling device
 |pubdate=1936-01-15
 |gdate=1938-02-16
 |fdate=1936-01-10
 |url=https://patentimages.storage.googleapis.com/d9/67/6d/6cbdb5f33cc76e/US2108652.pdf
}}</ref><ref name="Coanda saucers">{{cite journal
 |last1=Petit |first1=J.-P.
 |date=August 1974
 |title=Flying saucers R&D: The Coanda effect (English version)
 |journal=Science & Vie
 |issue=683
 |pages=68–73
 |url=http://ayuba.fr/pdf/coanda_disc.pdf
 }}</ref> In order to maximize such pressure difference between the two opposite sides, and since the most efficient MHD converters (with a high [[Hall effect]]) are disk-shaped, such MHD aircraft would be preferably flattened to take the shape of a [[Lens (optics)#Types of simple lenses|biconvex lens]]. Having no [[wing]]s nor [[airbreathing jet engine]]s, it would share no similarities with conventional aircraft, but it would behave like a [[helicopter]] whose [[Helicopter rotor|rotor blades]] would have been replaced by a "purely electromagnetic rotor" with no moving part, sucking the air downward. Such concepts of flying MHD disks have been developed in the [[peer review]] literature from the mid 1970s mainly by physicists [[Leik Myrabo]] with the [[Lightcraft]],<ref name="Myrabo 1976">
{{cite journal
 | author = Myrabo, L.N.
 | author-link = Leik Myrabo
 | date = 1976
 | title = MHD propulsion by absorption of laser radiation
 | journal = Journal of Spacecraft and Rockets
 | volume = 13
 | issue = 8
 | url = http://ayuba.fr/pdf/myrabo1976.pdf
 | doi = 10.2514/3.27919
 | pages=466–472
 | bibcode = 1976JSpRo..13..466M
 }}</ref><ref name="Myrabo 1999">{{cite conference
 | last1 = Myrabo | first1 =  L. N.
 | last2 = Kerl | first2 = J.M.
 | display-authors=etal
 | date = June 1999
 | title = MHD slipstream accelerator investigation in the RPI hypersonic shock tunnel
 | conference = 35th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
 | book-title = AIAA-1999-2842
 | location = Los Angeles, CA
 | url = http://ayuba.fr/pdf/myrabo1999.pdf
 | doi = 10.2514/6.1999-2842 
}}</ref><ref name="Myrabo 2000a">{{cite conference
 | last1 = Myrabo | first1 =  L. N.
 | display-authors=etal
 | date = January 2000
 | title = Experimental investigation of a 2-D MHD slipstream generator and accelerator with freestream Mach = 7.6 and T(0) = 4100 K
 | conference = 38th Aerospace Sciences Meeting and Exhibit 
 | book-title =  AIAA-00-0446
 | location = Reno, NV
 | url = http://ayuba.fr/pdf/myrabo2000a.pdf
 | doi = 10.2514/6.2000-446 
}}</ref><ref name="Myrabo 2000b">{{cite conference
 | last1 = Myrabo | first1 =  L. N.
 | display-authors=etal
 | date = July 2000
 | title = Experimental Investigation of a 2-D MHD Slipstream Accelerator and Generator
 | conference = 36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
 | book-title = AIAA-00-3486
 | location = Huntsville, AL
 | url = http://ayuba.fr/pdf/myrabo2000b.pdf
 | doi = 10.2514/6.2000-3486
}}</ref><ref name="Myrabo book">{{cite book
 |last1=Myrabo |first1=Leik N.
 |last2=Lewis |first2=John S.
 |title=Lightcraft Flight Handbook LTI-20: Hypersonic Flight Transport for an Era Beyond Oil
 |date=May 2009
 |publisher=Collector's Guide Publishing
 |isbn=978-1926592039
}}</ref> and [[Subrata Roy (scientist)|Subrata Roy]] with the [[Wingless Electromagnetic Air Vehicle]] (WEAV).<ref name="Roy 2011">{{cite report
 |last1=Roy |first1=Subrata
 |last2=Arnold |first2=David
 |last3=Lin |first3=Jenshan
 |last4=Schmidt |first4=Tony
 |last5=Lind |first5=Rick
 |last6=Durscher |first6=Ryan
 |last7=Riherd |first7=Mark
 |last8=Houba |first8=Tomas
 |last9=Anderson |first9=Richard
 |last10=Zito |first10=Justin
 |last11=Casanova |first11=Joaquin
 |last12=Thomson |first12=Carlton
 |last13=Blood |first13=Daniel
 |last14=Tran |first14=Dong
 |display-authors=5
 |date=20 December 2011
 |title=Demonstration of a Wingless Electromagnetic Air Vehicle
 |id=AFRL-OSR-VA-TR-2012-0922
 |publisher=Defense Technical Information Center
 |editor1=Air Force Office of Scientific Research
 |editor2=University of Florida
 |asin=B01IKW9SES
 |url=http://apps.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf
 |archive-url=https://web.archive.org/web/20130517063830/http://www.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf
 |url-status=live
 |archive-date=May 17, 2013
 }}</ref><ref name="Roy patent 2013">{{cite patent
| country = US
| number = 8382029
| status = patent
| title = Wingless hovering of micro air vehicle
| gdate = 2013-02-26
| fdate = 2008-12-23
| pridate = 2006-07-31
| invent1 = Subrata Roy 
| assign1 = University of Florida Research Foundation Inc
| url = https://patentimages.storage.googleapis.com/0b/a8/52/3c6718c040ad54/US8382029.pdf
}}</ref><ref name="Roy patent 2015">{{cite patent
| country = US
| number = 8960595
| status = patent
| title = Wingless hovering of micro air vehicle
| gdate = 2015-02-24
| fdate = 2012-12-19
| pridate = 2006-07-31
| invent1 = Subrata Roy 
| assign1 = University of Florida Research Foundation Inc.
| url = https://patentimages.storage.googleapis.com/25/43/bb/2bdc198ea976a9/US8960595.pdf
}}</ref>

These futuristic visions have been advertised in the media although they still remain beyond the reach of modern technology.<ref name="Science & Vie 1976">{{cite magazine
 |last1=Petit |first1=Jean-Pierre
 |title=Un moteur à plasma pour ovnis
 |trans-title=A plasma engine for UFOs
 |language=fr
 |date=March 1976
 |magazine=Science & Vie
 |issue=702
 |pages=42–49
 |url=http://ayuba.fr/pdf/S&V702-moteur_plasma_ovnis.pdf
 }}</ref><ref name="Popular Mechanics 1995" /><ref name="Scientific American">{{cite web
 |last1=Greenemeier |first1=Larry
 |date=7 July 2008
 |title=The World's First Flying Saucer: Made Right Here on Earth
 |website=Scientific American
 |url=https://www.scientificamerican.com/article/worlds-first-flying-saucer/
}}</ref>