Streamings in travelling thermoacoustic engines:
Gedeon streaming (or DC flow):
The cause of gedeon flow can be explained in two ways:
1. (in TASHE engine)
If you look at the graph of the stirling cycle you can see that the graph is not symmetric. When the pressure increases, i.e. there is compression and then heating of the gas, the change in pressure will be greater than when there is a cooling. When a bypasss but mainly a loop thermoacoustic stirling engine is used, the gas piston pushes out better from the hot side therefore the resulting in a harmful flow.
I think there may be another reason for the gedeon flow in TASHE machines, namely the Venturi effect, because the gas moving in the branch at the junction of the resonator and the loop can have a suction effect from the regenerator branch.
https://drive.google.com/file/d/1ziZWckUZGiEJ_u7e9uatpMoFst4D-gx2/view?usp=sharing
2. (in loop engine)
If you look at the picture You can see, that a pressure density circulates in the machine, pushing a flow.
The gedeon streaming dissipates heat from the regenerator and causes serious loss in the engine. The easiest way to stop this is to put a membrane in the engine through which the pressure wave passes but the flow does not, or to use a jet pump component that works similarly to an imperfect one-way valve and it stifles movement a little in the direction of the gedeon. This degrades the engine, but not, because in total yet it improves with retaining heat. Other solutions are possible...
http://en.wikibooks.org/wiki/Engineering_Acoustics/Acoustic_streaming
Gas dioda:
In case "b", the resistance (impedance) is higher, so a (imperfect) gas valve (or diode or jet pump) works.
It also seems to me that it is not good if the jet pump works too well because it has also an opposite effect for working the engine. This engine doesn't look like the best configuration ...
Jaime's compliance part.
I think, He maybe makes a jet pump in the compliance part. This jet pump is better, as the old one because its choking is less, since it does not narrow the tube but is in the wide compliance space. Of course I may be wrong ...
Am I wrong?
To tell you the truth, to reduce the chances of my mistakes, I need some experimentation.
I thought the Gedeon streaming could be seen by putting a fluff in a glass tube and it sweeps it away in one direction and this can apply at jet pump on same way.
First attempt to see the Gedeon streaming:
Regenerators are in the loop. It works very little, the lint doesn’t drift, it just vibrates a little.
Second attempt: There is a stack in the loop. The lint drifts, but the direction of this is variable!
What? What? What?
video: soon
My compliance solution: The compliance resonator
This is simple and very effective, but doesn't handle gedeon yet.
The maximum membrane width is 50 mm, 40 mm is close to ideal.
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You can also see from these that the active diaphragm thermoacoustic engine is currently the best thermoacoustic engine in the world!
Multi-core thermoacoustic engines:
In the case of externally heated machines and/or models, since we cannot solve the heat exchange well with core (regenerator, stack) wider than 25mm, perhaps 30mm, using several cores can be a method of increasing performance.
These can be placed in parallel, or in series, or perhaps mixed. The disadvantage of this method is that the engine has to be heated in several places.
It seems that with parallel cores, two cores are much stronger than one, but three and four are already weaker.
It also seems that it doesn't matter at what temperature we drive the machine. It looks like we can use 4 cores for LTD (low temperature difference engine) because a quad core machine is LTD, but stick with 2 core for HTD (high temperature difference engine ).
Regarding the serial cores, I tried the serial two cores on a few HTD engine, and I experienced an increase in performance with them as well.
For now, there was no more way to experiment with multi-core themes. Is it possible that by correctly applying the multi-core solution, not only the performance but also the efficiency can be increased?
About the generator of thermoacoustic generators:
Heat can be produced from heat thermoacoustically with an efficiency of over 40%, but then the sound must be converted into electrical energy with the best possible efficiency!
These are usually used or experimented with these:
-piezo crystal:
http://www.baz.umd.edu/labs/thermoacoustic.html
-triboelectronik:
https://www.youtube.com/watch?v=joetshqFAOM
-Magnetostrictive Alternator:
https://www.techbriefs.com/component/content/article/tb/pub/techbriefs/mechanics-and-machinery/17674
http://www.spaceref.com/news/viewsr.html?pid=43441
-piston:
-membrane, armature (eg subwoofer):
Making a generator for a model:
The my experimental generator. So this is an experimental ...
First, I made my coil based this website
http://www.creative-science.org.uk/gensimple1.html
https://www.youtube.com/watch?v=t-Xwv-D0zQA
and I bought a such 30 x 5 mm neodymium magnet.
Use thin wire (0.1-0.2 mm) at least 2-3 hundred turns.
If you want only that leds light you do not need any electronics. Leds must be even number, and parallel and you must connect them and in 50 - 50% opposite polarity. But thus leds will blink.. If you want to charge something you need an electronics.
http://www.creative-science.org.uk/gensimple2.html
http://www.creative-science.org.uk/tubegen.html
Attention! 1 LED alone does not work on AC power. Connect another LED to it in reverse, or use graetz bridge!
-flywheel:
https://www.youtube.com/watch?v=ykEUDhCA1bA
https://aip.scitation.org/doi/full/10.1063/5.0022315
-turbine:
The invention of the thermoacoustic turbine by Attila Kovács (Blade) and my Tibsim ...
Demonstrated by Attila on 13.09.2010,
https://www.youtube.com/watch?v=ZlpXfhGvIcg
And the reconstruction of the drawing of the first thermoacoustic bidirectional turbine on 15.09.2010:
Our after the thermoacoustic turbine was developed by Aster:
http://www.aster-thermoacoustics.com/?p=1365
Video:
https://odysee.com/@Tibsim:9/Thermoacoustic-turbine-6.:b
My some idea for thought provoking these are not perfect... :
Rotary generator for thermoacoustic turbine nodel:
https://drive.google.com/file/d/1Czrwa33kVn6AlVNoYbr9Hzy3nn5q8luk/view?usp=sharing
Diametric magnet size: 10 mm x 20 or 50 mm rod
Coil: 0.25 mm 300 turn
Some my thermoacoustic turbine idea:
I think it is possible that there is no need for a bidirectional turbine, because you can extract the energy with a unidirectional turbine. For example, if there is no resistance in the inward direction, the engine can gain momentum there that is added to the outward direction. If this is true, then e.g. a simple Pelton turbine or other simple one directional turbines can be used well.
-with thermomagnetic generator (???):
According to Fellows, it is possible to make a vibrating generator without moving parts by using the Curie point:
http://www.google.com/patents/US20060266041
-electrostatic generator:
http://eprints.gla.ac.uk/202960/7/202960.pdf
Tubes connectings:
When attaching the tube to a wider wider resonator, do not use a funnel (page 19)
http://slideplayer.com/slide/5815243/
More interesting experiments:
The Trumpet Engine:
I gave this name to its because this engine works in a surprisingly wide frequency range.
By changing the long of the resonator tube, the frequency can be changed as if it were a trumpet.
Thermo-flute:
https://www.youtube.com/watch?v=yUwAB4u6L2w
Cooling with sound: soon
Model building tips:
1. Machines usually only work when they are fixed. So not in the air!
2. Use electric insulating tape.
3. Use a double-sided adhesive strip under the membrane.
4. Hole on the membrane.
5. If you heat the machine, there should be no wind or breeze in the room!
6. If the machine is completely enclosed, check how insulated it is before starting. Push in the diaphragm for approx. 5-10 seconds and see how long it takes you to go back when you release it! At least 2-3 seconds! If the machine is completely insulated, does not leak, it will not work alsó! Puncture it with a very tiny needle somewhere, but not on the membrane!
7. If you use a gas resonator, and the machine is open, You must checking It not leaks anywhere else! Before you start, make sure you put an insulating tape everywhere! Many machines, if not well insulated, will not start. If the engine have started maybe It can run with not good insule.
8. First you just must want to make a working model with perfect copy (the sizes, materials, everything).
9. For these machines, the frequencies must be coordinated. At the resonator, the diaphragm weight (coin weight trying) must be set. At gas you must try resonator for pipe length. If the machine doesn’t work, you must blow it into the tube and you’ll hear it almost or totaly doesn’t want to work. If almost, extend or shorted it a little, etc.
10. Persevere, try, think, ask, and sooner or later succeed!
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IDEAS:
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Fordítási találatok-piezo cryst
