[ATM] "Synthetic jets"

[artbianconi@blast.net]

Until they proved to be unreliable, conical transducers were the 
preferred mechanism for fogging water in humidifiers. They were 
dropped eventually in favor of an old fashioned and far more 
reliable wick and fan.

Reliability aside, there's not enough surface area on such 
devices to move the volume of air needed to cool your mirror 
much less disperse air within a tube.

Add the problem of boundary layer stagnation and moving it 
around a series of light baffles and challenge gets worse.

I can't imagine that "tweeter" doing much except maybe getting a 
mosquito aroused.

Everything else being equal (it rarely is!) a larger diameter fan 
moving slowly, will move more air, more efficiently than a smaller 
diameter fan spinning faster. The smaller disk area of the smaller 
fan makes it easier to balance and thus get less vibration but 
today's modern manufacturing methods make blade balance a 
non issue. 

DC brushless ducted ball bearing fans with permanent magnets 
are inexpensive, use little current and are reliable. They are 
available in a wide assortment of sizes and voltages and do an 
excellent job.

Where to place them, how to mount them and applying 
supplimental heat are three whole other conversations,

Art Bianconi

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