The Ruben's Tube worked wonderfully at the event last night! No glitches, perfect behavior -- though it did blow out twice. We had some wind, and I was pushing the bass for good effect.
All in all, it seemed to be popular, and I had a number of great conversations both before and after with technically minded people.
I also met the guys doing the effigy at Flipside, so that's good! Once school is behind me (just a few weeks... argh!) I'll spend some time with them at the warehouse and we can finalize the arrangements.
Of the various conversations (why are there small holes and big holes? {better re-ignition behavior and less pressure loss), Why the flare at this end {I couldn't find a smaller end plug so I adapted}, and so on... technical trivia) there was one audio enthusiast (or perhaps engineer) whose name I do not remember (actually I don't remember any names! sorry folks) had a very interesting idea.
Basically, a mechanical band-pass filter upstream of the gas injection, acting as a one-way valve to the tube. Simple to build; holes in a barrier, with flexible flaps over them that seal in response to backpressure; the size of the holes would need to be tuned, though, for optimal behavior at my preferred frequencies (whatever those end up being). Anyway, a pressure pulse would drive gas into the tube, but on the pull-back the valve would close up preventing me sucking air into the tube and blowing out the flame.
It would be difficult to add this now, with everything sealed up, so I may have to make a new tube sometime to test it. Or, after the show, I may try to tear down and re-build a tube to test the theory.
It was fun to be amongst fellow mad scientists and enthusiasts! I am so looking forward to being part of the geek community again.