Re: The science behind streamer sounds

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

Here's what I think about the sound from streamers.  Others can probably say
a lot more . . .

When the streamer is formed/forming, it heats up (rather quickly) and all
the air that it's ionizing and air around the streamer changes temperature
and expands.  As the streamers form and "disappear", the air expands and
contracts rather quickly.  At 120 bps, you should here a sound with a base
frequency of 120 Hz as the air expands then contracts at each bang when more
energy is added to the arc.  If using a static gap, the frequency will most
likely be higher depending on input power and gap spacing.
Some of the noise is from the spark gap, especially if you're using a
triggered gap, but the streamers are typically much louder.
Hope that answers the question well enough!

Sean Taylor