This website is the twin sister of this site. If you haven't heard of hotair and stirling engines, you may want to read this site first:
https://stirlingtechnology.blogspot.com/
The essence of how thermoacoustic engine works :
We produce a very strong sound (gas oscillation) from thermal energy, from which we makes electrical energy.
Achievable efficiency can be over 30-35% or more!
At these engines we strive to make hot air motors, stirling engines that contain fewer materials and parts and are simpler to build. In the case of free piston stirling engines, we could see that they could omit crank structures (flywheels, levers, etc.), and we can see also engines where the piston or pistons are not made of solid material, rather those are from liquid for example from water. In the thermoacoustics, we go even further and make the pistons out of air or from a more suitable gas. If we take a pipe, the gas in the it is flexible and has momentum so we have geometrically formed a gas piston in it right away, which did not have to be carved precisely for the cylinder, does not wear out, does not corrode, is not expensive, but durable! So below we mostly show machines where at least one of the pistons is made of gas!
Thermoacoustic engines also work the other way around, if we create sound ( gas oscillation ), for example with a loudspeaker in it, then one part heats up and the other cools down, so it works as a heat pump (fridge).
one of my models:
About the sound:
Normal conversation from 1m = 40-65db
At 65dB, the value of pressure changes is 0.05 Pa
(move of the gas: 0.2 μm
Temperature changes: 40 μK)
City transport 85db
Air hammer from 1m = 100db
Vuvuzella horn from 1m = 120db
Pain threshold 120-130db
Intensity greater than 30,000 times a
165db (where your hair is said to burn)
(For 180 db the value of pressure changes: 0.3 bar
Gas moves: 10 cm
Temperature changes: 24 K)
Theoretical max. at atmospheric pressure approx. 194db
http://www.youtube.com/watch?v=HXedcb27who
Thermoacoustic generators generally are operated at 2-3 or even on 40 bar pressure with one or two exceptions with a more ideal working medium than air, such as helium.
There is no need for sound insulation, fortunately no sound comes out of them, as the system is closed and the wall of the machine is thick enough not to be deformed by gas pressures! As surprising as it may be, it is enough to keep sound coming out of it, max. a soft hum is heard as the raging pressure waves inside, possible diaphragm pistons shake the whole machine a bit.
Due to the simple construction of the thermoacoustic generator, it can be cheaper than even a device that uses fossil energy, and because there are minimal moving parts in it, it is extremely reliable and has a long service life.
Usability of the generator:
-Solar energy
-waste heat
-geothermal energy
-exhaust heat reuse
-General generator that can be heated with anything
Other areas of thermoacoustics
- Gas liquefier
- Refrigerators
- Medical imaging tool
- Pulse Jet engine
- In jet aircraft, missiles, chimneys, other internal combustion “pipes”, power plants, the combustion has such a high power density that such a strong thermoacoustic phenomenon can occur, which can damage the engine or structure. One branch of thermoacoustics deals with the prevention of these harmful phenomena.
Thermoacoustic generator that uses waste heat (by Aster thermoacoustics):
solar:
thermoacoustic gas liquefier:
Great presentation of thermoacoustic engines:
