Michel Jullian wrote: > 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
For sake of argument assume there is no ion wind. What you have are two oppositely charged bodies where one (the wire) is above the other (the tube). Each will be attracted to the other. The tube will accelerate upwards and the wire will accelerate downwards. If the attractive forces are opposite AND equal the lifter will not take off, but since tube has some freedom to move it will rise until it is stopped by the cross member. However, if these forces are opposite but not equal the lifter will either want to ascend or descend depending on the polarity. On the other hand if an ion wind is the cause of this net force then it should be possible to reduce the net force by inserting a horizontal neutral (e.g. paper) shield in the gap between the wire and the tube. This shield would be fixed to the struts of the lifter. Harry > ----- Original Message ----- > From: "Harry Veeder" <[EMAIL PROTECTED]> > To: <vortex-l@eskimo.com> > 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 >> >
