This project is a subproject of #Ion wind loudspeaker experiments.
According to my calculations, the maximum wind pressure that a single ion wind stage can achieve is fundamentally limited. So, to increase the loudness of sound output, I decided to try stacking a few stages.
This blower has one corona electrode (the metal frame inside the pipe supports thin wires), and a stack of grids as the other electrode.
The idea was to figure out, if the ions can go through the first grid, be accelerated again between first and second grids, and so on.
How do I know, how much of the ion flow goes through? Well, I can just measure the electric current that goes out of each grid.
The results are a complete disappointment. The first grid receives the majority of the current. Some small fraction makes it to the second grid, and lands there. There is bugger all current from the last grid =(
So, stacking grids doesn't look promising. It should add a few percent to the max pressure, but I need a major boost (two or three orders of magnitude) to make a practical loudspeaker.