From: "Terrell W. Fritz"
Date: Fri, 25 May 2001 17:09:41 -0600
Subject: [TSSP] streamer formation modeling
Hi All, Since Paul's Tesla coil modeling project has now done secondary behavior, primary to secondary coupling, losses... and is now running up against real time streamer loading effects, I thought I would mention "my" thoughts on streamer formation. Mostly from reading about 30,000 Tesla list posts :-)) I really do read them all as moderator as I am sure you all do :-))) At first, the streamer needs to break out or start ionization in the air. This usually occurs at a little defect or odd spot on the toroid where the field stress reaches around 30kV/cm (now refined to 26kV). Once there is ionization, heating effects seem to be really important in that the hot air forms a very conductive path outward into lower field stress regions. Since the voltage reduces drastically outward from the toroid, current wants to flow. Since the current is AC, the streamer tends to also feed the space capacitance around the growing streamer (more current). These currents only have a say 3% duty cycle so the heated air path is important in forming a conduit for the next pulse to push the streamer further and further into the surrounding air. The voltage is not so important at this point as is the current and its heat generating ability in increasing the low resistance path length and thus the streamer grows in length with each pulse. Eventually, the streamer energy is no longer sufficient to sustain the heated air path and the streamer fails. The path suddenly disintegrates and the toroid receives higher voltage again and a new streamer starts up. This is obviously a very messy subject in which not to much is known (especially quantitative numbers). Three people that I am not sure are in our tssp group (aside from those I know are here) come to mind. Maybe we should entice them to join at this point if they wish ;-) Streamer formation modeling is a subject where we can use all the help we can get! Jim Lux jimlux@earthlink.net Gary Lau gary.lau@compaq.com Antonio Carlos M. de Queiroz acmq@coe.ufrj.br The TSSP project page is at: http://www.abelian.demon.co.uk/tssp/ Work is ongoing. If you wish to contribute, or just follow developments, please join the mailing list by emailing to majordomo@abelian.demon.co.uk and put subscribe tssp in the body of the message. I zipped up the recent posts here at: http://hot-streamer.com/temp/[TSSP]TimeDomainModeling.txt I will copy the above and see if they are interested in joining Paul's group here. Cheers, Terry
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.