Dear Paul,


I have some questions regarding a spiral tube layout silencer system that
you have apparently developed for rotary engines.


I am very interested to hear more about this because I am currently building
a range of rotary engines for aircraft with Paul Woelfle from Germany. He
mentioned that you had actually made one and tested it.

Could you offer me any advice on this.

Look forward to hearing from you and thanks very much,

All the best, Gilo

http://www.youtube.com/watch?v=TMWyrzisRjY

Parajet International Ltd

Beaumont Business Centre

Woodlands Rd

Mere

Wiltshire

BA12 6BT U.K.

Tel/Fax: +44 (0) 1747 861368

Mob: +44 (0)7971 494541

www.parajet.com

We have several designs that work. Th basic principle is; don't put anything
in the muffler that is not cooled. It could melt and block the exit
causing the engine to reduce power. We have had one crash where this has happened.
The rotary exhaust runs a few hundred degrees F hotter than the piston
engine so material specs are critical. If weight is critical, and it seems it
is in your application, the best choice is sheet Inconel about .035 inches thick.

Ram air is fed through the center pipe to cool it. The diameter
of the exit pipe controls the noise. The smaller the diameter the
quieter. On a 250 HP 13B p-port engine 2 inches in dia. is very quiet.
Square entrance and exit pipes are better than round.

Here are a few ideas.