Sure Harry it's ion wind. Naudin's comment, athough somewhat misleading, is correct too. The collector (bottom negative armature) is indeed attracted upwards to the "parachuting" positive ion cloud _generated by_ the corona wire (the ion cloud, dragging ambient air along, is pulled downwards with an equal and opposite force, hence the wind). This upwards pull constitutes most of the lift, because most of the positive charge (whose total value is equal and opposite to the collector's negative charge due to charge conservation) is in the air, so the wire itself carries a comparatively small positive charge, so it's contribution to the lift (upwards push from the positive ion cloud below) is comparatively small.
Same reasoning holds if you reverse polarity, in all cases you get thrust in the direction from the collector to the wire (not necessarily upwards BTW). Michel ----- Original Message ----- From: "Harry Veeder" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, February 03, 2007 4:13 AM Subject: Re: [Vo]: Re: Fred's Van de Graaff Antics > Michel Jullian wrote: > >> In spite of, or rather thanks to the ion fan out feature, this design has >> beaten as I had expected all other lifter designs in terms of thrust per unit >> area, by a comfortable margin (3 times that of a standard lifter e.g. >> Naudin's, 1.5 times that of a flat grid De Seversky ionocraft), at the >> expense >> of a 40% lower thrust to power ratio. >> >> http://www.blazelabs.com/e-exp06.asp >> >> Michel >> > > > > Can ion wind explain this?: > > http://jnaudin.free.fr/lifters/tubular/index.htm > > "Note from Jean- Louis Naudin : Congratulations to Greg Vizza and to Francis > Daran, there experiment proves definitely > that the main Lifter thrust is the result of an upward force of the aluminum > armature towards the virtual armature generated > by the wires." > > This is a device several guys on this list could build and test. > > Harry >
