Gauss, I think its great you are doing some experimental work.
The vibrations can resonante water apart and possibly help the gas move out of the tubes or electrodes quicker.
Here is a link youtube for Tibetan singing bowl.
There were a couple others that people put water in their bowls.
The resonance of the bowl would cause the water to bubble , this always interests me.
http://www.youtube.com/watch?v=rdOJZDWJkuk[url]http://www.youtube.com/watch?v=CycFRkWboQU/[url]
Most of us should already know a pond fogger piezo crystal makes a cold fog sitting just covered by water or 1" or so under.
Puharich's sparkplugs were covered with (vitreous ceramic mixture containing piezo family materials).
Most likely others, you may have mentioned this.
I think if long tubes are mounted secure at the bottom, epoxied or potted in, that they will vibrate more longitudally or at their tips.
Using no spacers at the tip.
Pretty soon I will have a set of 12" tubes mounted like this, hopeing also for vibrational effects.
I have 2 large pieces of piezo ceramic from a ultrasonic cleaner small tub with lead wires but can't find out what voltage or signal to apply to the ceramic.
Guess I could just apply AC voltage with the autotransformer. Have a feeling this will possibly only make fog again.
