Ceramic rather than plastic makes sense for this kind of discharge indeed (dielectric barrier discharge, the kind used in ozonizers), but my question was, why piezoelectric? I thought maybe you were thinking about converting vibrations into electricity, or electricity into vibrations, but maybe you were simply referring to metallized ceramic?
Michel ----- Original Message ----- From: "William Beaty" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Sunday, June 24, 2007 8:46 AM Subject: Re: [Vo]:Filament ion jets > > >> On Tue, 12 Jun 2007 10:36:57 +0200, "Michel Jullian" <[EMAIL PROTECTED]> >> wrote: >> >Applications of EHD to aircraft aerodynamics has been a subject of >> >intense research recently, lookup e.g. OAUGDP. >> > >> >Why _piezo_ ceramic tiles BTW? > > Suppose that polyethelene-covered conductors at AC high frequency can > produce plasma layers. If instead we use high-K dielectric like barium > titanate or PZT, then the same plasma effects will also occur at lower AC > frequency (perhaps several thousand times lower freq than with PE > plastic.) Also, a ceramic insulator would better survive damage from > corona effects. And, if the ceramic contains no carbon, then an > arc-through would self heal after the melted material cooled down. > > If military aircraft are seen to be covered with barium titanate, well, > perhaps it's an antireflector coating for radar. Or perhaps it's there > for creating a plasma layer whenever the aircraft is electrically driven > with a huge voltage. > > Where AC is concerned, dielectric materials resemble conductors. For > example, place some dielectric pucks upon a metal electrode, then drive > that electrode with HV at high frequency. If any plasma streamers were to > appear, they would leap from the tops of the dielectric pucks, and not > from the metal surface. > > > (((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) > William J. Beaty SCIENCE HOBBYIST website > billb at amasci com http://amasci.com > EE/programmer/sci-exhibits amateur science, hobby projects, sci fair > Seattle, WA 425-222-5066 unusual phenomena, tesla coils, weird sci >
