bubbles flow viz

A machine which generates bubbles with variable flow rate, sizes, colours (possibly fog filled), for observing air flow in various situations, and generally making an awesome bubble show.

Current air flow visualization machines mainly seem to use a stream of fog. I have noticed some bubble based machines for observing liquid flow. Spaced bubbles would be good because they'd allow you to track individual points as well as direction of flow.

How it might be made (just some ideas): a bubble wand supplied by a gas hose and a bubble-solution hose, and some control cables. The gas hose is attached to a compressor which can send variably mixed coloured gas down the hose at various flow rates (so you can computer control the colour and flow rate of the gas coming out of the compressor in real time). The fluid hose pumps fluid to the wand, perhaps with a mechanism for changing the viscosity of the fluid (this might be part of the mechanism for regulating bubble size). The bubble wand would have a series of computer controlled valves, which could control their diameter rapidly (perhaps this would help with bubble spacing and size). There would probably have to be some venting mechanism somewhere to prevent bad pressure variations in the gas hose.

A really nice refinement would be to have these computer controlled valves mounted in the hose itself, so that a bubble wand could be a relatively cheap item, which you just route the hose around, then you could have all sorts of shapes of bubble wand, from a straight line, to big circles or squares, or whatever.

I got the idea when I was on a rocky exposed bit of coast, and I had some children's blowing bubbles. The bubbles were really wild in the chaotic coastal air, and watching them really gave an idea of what the air was doing. A machine which had more and better bubbles would obviously make things even more obvious.