The whole misting cycle and how many nozzles question is one big reason why I'm here and posting.
Perhaps there's some good info on one of the, well... growing groups...
But this being an academic endeavor, it's a good place for data and ideas to be shared. So I see this place as where the "more information" will end up being.
For my plan, I can't thank you enough, adam, for posting the information you have. Between the 4 nozzles for the good sized chamber to the different cycles- that's really awesome for me. Now I know that I can use probably just 2 for my experiment- one at the top pointing down, and one at the bottom pointing up.
The experiment that I'm running this summer is the low pressure (usually the head pressure of a tank pump) vs. high pressure (80psi). The idea is to compare growth as well as cycle required for the low pressure system. The set up will be 2 5 foot sections of 4" PVC using 1.5" elbows as the growing locations- and both systems will use the same water source.
The reason that's what I want to experiment- I see 3 types of "aeroponic" towers- one drip one, low pressure, and high pressure. The drip system runs 15 min on, 15 min off- so during a day, that's 12 hours of pumping. The high pressure I was targeting was 3 seconds on, 3 min off- or about 15 min a day. So if one was to develop a stand alone system using a small battery and solar collector- the high pressure system is very feasible. The low pressure system is slightly less expensive to put together, and if it can be anywhere near as good- then it would be a less expensive system in isolated areas.
I know the high pressure is the "true" system that NASA developed- but reading an SAE paper kind of implied that the lack of gravity had a lot to do with the small droplet size requirement- small enough to not get into droplets that cover the root- as it can't drain off. but big enough to hit the root systems. It's SAE 2000-01-2507 if you are interested.