Let's assume that you have an external source of mechanical power, and are using it to move hydraulic fluid from a low pressure reservoir to a high pressure reservoir.

Now, using a high efficiency linear actuator (piezoelectric or a solenoid, most likely), open and close a valve at 60 Hz (or 50 Hz for you Brits). This valve leads from the high pressure reservoir, to a specially shaped reflector with an integrated linear alternator, to the low pressure reservoir.

The opening and closing of the valve will produce a sound wave, which bounces off of the linear alternator, generating electrical waves at the same frequency as the sound wave.

The speed of sound in the hydraulic fluid, and the distance between the valve and the alternator, and the frequency (60 Hz or 50 Hz), will determine the phase difference between the power supplied to the actuator and the power produced by the alternator. It may be desirable to have a variable-length section (such as a trombone has) between valve and alternator, to control whether the system produces real power, reactive power, or some combination of the two.

If it is not necessary for the system to match it's output phase with that of an external power source, then we can replace the electrical actuator that drives the valve with a acoustically driven actuator, using appropriately timed feedback from the output.

PS: This idea was inspired by the auxetophone, which is surely the coolest type of sound amplifier there is :)
-- goldbb, Feb 18 2011

Don't tell a Brit to open and close a valve at 50 Hz. S/he will think you are talking about a vacuum tube. They will think it odd to run water ("wata") through a vacuum tube.
-- sqeaketh the wheel, Feb 20 2011


//water ("wata") //

You mean 'wahdda ("water")'.
-- MaxwellBuchanan, Feb 20 2011


sounds like a Rue Goldbrick device.
-- WcW, Feb 22 2011



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