Lamina Flow/Thermoacoustic engine question

[bilaljafrani]

My first post in these forums. I am going to be making a lamina flow/thermoacoustic engine for a project in college. The thing i need to know is what the "choke" is for. I haven't been able to find any information related to it. Thanks in advance.

http://www.stirlingengines.org.uk/thermo/fig2.gif

here is what it looks like...the choke is where the O-ring seals are..i guess =)

[Ian S C]

I built one a number of years ago, stainless steel instead of a test tube. I put a thin tube through the steel wool to a space at the end of the tube were it is heated. As for the 'choke' there may be some advantage in slowing the air flow, but other than that, there must be a reduced diameter there to make the joint between the hot tube, and the power cylinder. It should go well, the important thing is to get the piston and cylinder a perfect fit, NO leaks, and NO friction. Ideally you should have 3 ball bearing races, 2 to support the crankshaft, and one for the big end of the con-rod, remember as little friction as possible. Ian S C