George;

 

Nice design.  Has anyone run one of these yet.

My concern with the tangential muffler is something called ‘swirl flow choking’ – discovered in connection with a similar attempt with gas turbine exhaust.  High circumferential velocity tends to keep the flow from moving out the end, and consequent pressure buildup.  I don’t know whether it applies to the pulsed flow, but it might, and your conical restriction toward the outlet could make it worse.

 

To avoid that possibility in my tangential muffler I added internal vanes at a 45 degree angle opposite the ports, and extended the header pipes into muffler to a squared end. Disrupts the circumferential flow and helps direct the exhaust toward the exit.

 

Your depiction of the idealized sounds waves going axially; ah-h, well; maybe/maybe notJ.

 

Al G

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Thursday, October 08, 2009 1:14 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Your muffler

 

----- Original Message -----

From: Kelly Troyer

To: Rotary motors in aircraft

Sent: Thursday, October 08, 2009 9:32 PM

Subject: [FlyRotary] Your muffler

 

  George,

   Do you have a photo or drawing available of your muffler design..........I seem to

remember seeing some design info in the past but do not know where to find it......

 

 

Thanks,

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

 

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


> Ed,
> Cones are the GO.
>
> Any bare edge will take a battering from the heat and shock waves. Cones
> formed back to back eliminate any edges.
>
> There must be supporting structure for the cones, I've used 1/4" solid
> round bar welded into the exhaust skin.
> George (down under)