Thermo-acoustic Stirling Engine kit, twin cylinder

What is a Thermo-acoustic Engine?
Thermo-acoustic engines are very simple devices for converting heat into motion. They are sometimes called lamina, lag or resonant engines, and they rely on rapid pressure fluctuations for operation. They come under the general umbrella of Hot Air engines, but unlike conventional Hot Air (or "Stirling") engines they only have one moving piston.

How do they work?
There is a mesh bundle (the "stack") inside the main tube, heating the tube at the end of the stack causes the stack to resonate, and generate sound waves (these sound waves are inaudible to the human ear) inside the tube. Sound waves are basically fluctuations in pressure, and we can use these fluctuations in pressure to drive a piston in and out, and then via a connecting rod drive a flywheel round.

Eco-friendly
We have successfully attached magnets and pickup coils to this engine and have been able to light up a series of low power LEDs. This points the way for further experimentation, and several energy providers are investigating using Thermo-acoustic engines to help provide electricity in the future.

Operation
This engine is very straightforward to operate. Fill the burners up to the safety level and trim the wick to the correct length. Light the wick, wait about 30 seconds and give the flywheel a little nudge. The engine will start to oscillate over top dead centre or bottom dead centre, with each oscillation getting larger and larger. After a few seconds the flywheel will perform a full revolution and the engine is up and running. It will steadily accelerate up to about 1700rpm over the course of 20-30 seconds, when it gets to 1700rpm it will suddenly jump up to 2700rpm, which is the engine's ideal harmonic frequency.

In 2007 we were visited by the President of the Institution of Mechanical Engineers (ImechE), Mr John Baxter. He was very pleased and impressed to find out that such a beautiful and precise Stirling engine was being manufactured by us here in England.

Mr Baxter was so pleased with our engine that he decided to feature it in his series of lectures given all around the world to senior figures in the alternative and clean energy industry.

ImechE have taken 80 of our engines for Mr Baxter to give as gifts to dignitaries as an example of the quality of engineering and manufacturing still being done in England.

The Institute are very happy to promote and endorse our engines, and we are able to prove their endorsement should anyone wish to verify it.

In addition to this honour, our engine has also been endorsed by the Glasgow  Science Museum in Scotland, where they will be displaying it alongside the original 1800's engine designed and built by the Rev. Robert Stirling.

Technical details:

• 32mm (1.25") diameter brass flywheels rim with aluminium spokes.
• 136mm x 86mm (5.375" x 2.375") solid aluminium anodised base plate.
• 63mm (2.5") overall height.
• 9.5mm (0.375") diameter pistons.
• 150mm long borosilicate (high temperature glass) main tubes.
• Stainless steel screws throughout.
• Ultra low friction demagnetised and degreased bearings.
• Fully CNC machined, giving crisp, clean tidy edges all over.
• Engine parts ultrasonically cleaned before hand assembly.
  

Buying guidelines:

Operability - We ABSOLUTELY GUARANTEE that every engine we sell will run as advertised. If your engine struggles to run as advertised then we ABSOLUTELY GUARANTEE that we will offer all possible help to you until it does. All our engines are individually packed in supportive packing foam and rigid cardboard boxes, which ensures safe arrival of your engine.

Feedback - 99.9% of transactions are completed satisfactorily to our buyers without any further help or assistance from ourselves. If you are unhappy in any with with your purchase please contact us and allow us to help resolve the problem BEFORE leaving negative or poor feedback. We want you to be completely happy with your purchase, and will ALWAYS do all we can to help to resolve the problem, but we can't help if you don't contact us.

UK Delivery -

• UK deliveries are sent either same day or next working day via Royal Mail 1st Class, with a Royal Mail quoted delivery time of 1-2 working days. Weekends and bank holidays are not classed as working days. 1st class deliveries cannot be considered lost until at least 14 days after despatch. There are no tracking numbers for 1st Class deliveries.

Outside UK Delivery -

• Deliveries to addresses outside the UK are sent by either Royal Mail Airmail Small Packets or Fedex, depending on your selection at checkout.

  Airmail deliveries are sent either same day or next working day via Royal Mail Airmail, with a Royal Mail quoted delivery time of 5-7 days. Weekends and bank holidays are not classed as working days. Random customs and security inspections can extend this by another 14 days. Airmail deliveries cannot be considered lost until 28 days from despatch. We must stress that the vast majority of engines arrive inside 10 days all over the world. There are no tracking numbers for Airmail deliveries.

  Fedex deliveries are sent same day or next working by a 2 working day worldwide service. Weekends and bank holidays are not classed as working days. If you buy after 11am GMT on Fridays your engine will be despatched the following Monday. If you pay for Fedex you MUST provide us with a telephone number that Fedex can call if they cannot find your address. Failure to do so could seriously delay your parcel. A tracking number will be emailed if you choose Fedex, but in most cases the engine will arrive before the email.