flyrotary@lancaironline.net Mailing List Archive

Kelly,

My apologies, Yep! great idea when using a muffler. Can make a really long muffler as well. I can visualize now what your getting at with the cross over two muffler system cooled by outer covers with forward inlets, should look cool as well.

I have always like the inlets of the Mistral test aircraft with their jet style inlets. I assume yours would look similar? Different aircraft I know.

George

George,

I am sure you are correct in your assesment concerning sound if implemented

without a muffler system included................Have you ever heard the exhaust

noise the piston powered "Aero Commander" twin engined a/c make using such

a "Augmentation" system.............I do not know for sure there is a muffler in their

system but I do not think there is...............I am sure that a muffler of some kind

will be needed................My hope is to reduce the drag of the external exhaust

system by enclosing it in the large semi buried tubes and perhaps even gain a

small amount of thrust from the air flowing through it being heated............

Probably just wishful thinking on my part!!

--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

-------------- Original message from "George Lendich" <lendich@aanet.com.au>: --------------

Kelly,

I think what your referring to is exhaust augmentation whereby an exhaust tube runs into another open tube, creating a negative pressure sucking in air around the front end of the larger open tube. This is very successful with extracting air from the cowl - however it won't suppress sound, most likely it make it louder with sound waves escaping through the front open end.

If I understand you correctly.

George ( down under)

Lynn,

Another thought.............What do you think an "Extractor" system (In my "Delta's" case

one on each side of the bottom "V") consisting of large diameter tubes (5-6" ?) exiting

behind the cockpit with 2" tubes down the middle and open to forward motion and prop

blast would do to noise level ??.............

--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

-------------- Original message from Lynn Hanover <lehanover@gmail.com>: --------------

Lynn,

I would like to see a drawing and I am sure others of the group would also !!.............I

know this is splitting hairs but I am planning on splitting my exhaust after the collector to two

mufflers (no good reason other than the Dyke Delta bottom skin has a "Keel" shape (V)

and I want to keep the bottom symmetrical with a muffler (recessed with cooling air) on each

side of the "V" ) and I wonder what size you would use from the 2.75" to branch off to the mufflers ??.........

Again Thanks,

Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

The single pipe would about 5.9 square inches. A 2" tube would be 3.14 square inches. So I would use 2 inch tubing. Most modern V-8s have a combiner "X" fitting in the center of the two pipe system. It produces lower back pressure and a less harsh tone.

I will make some drawings.

Lynn E Hanover