Mark;

 

Yes; I have a tangential muffler.  It is light weight, does a nice job of quieting things down, and based on dyno results, has little if any power penalty.  It is made of .045” inconnel; 5 inches in diameter, and has worked great for 150 hours on my 20B.  I have internal vanes on the inside opposite the ports at 45 degree angle to help break up the pulses, and help direct the exhaust toward the exit at the aft end, which is conical down to a 2 ¾ exit pipe.

 

I also have a secondary SS muffler of my own design which knocks another 6 db off the noise.

 

I think one advantage of the tangential muffler approach is the expansion of the gases close to the port, and although not computable due to other variables, probably immediately drops the temp somewhat in accordance with Charles Law.

 

Best,

Al G

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Thursday, October 01, 2009 7:36 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Quiet is Deafening

 

Kelly,

 

You just need to fly at Mach 1 so you stay ahead of the sound.  ;-)

 

Can anyone report on the effectiveness of the tangential muffler in actual real world situations?  (As I recall Al G. is running a tangential muffler on his Velocity.)  I ask because I'm in the process of building one for my Lancair with the hopes that it will work better than the DNA muffler that I'm currently running.  I think it will work better at reducing the noise level in the cabin, but at what cost to power?  Hopefully, this will save me the cost of a new Zulu ANR headset.  Comments appreciated.

 

Mark S.

On Wed, Sep 30, 2009 at 10:01 PM, Mike Wills <rv-4mike@cox.net> wrote:

Kelly,

 

 If you think the quiet is deafening go fly behind a rotary - now thats deafening!

 

Mike Wills

RV-4 N144MW

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

From: Kelly Troyer

To: Rotary motors in aircraft

Sent: Wednesday, September 30, 2009 7:15 AM

Subject: [FlyRotary] Quiet is Deafening

 

Anyone out there ??.....................<:)

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

 

-------------- Original message from "Patrick Panzera" <panzera@experimental-aviation.com>: --------------

Hey gang!

 

I came across a rare find this weekend.

Any serious rotorhead will certainly appreciate this.

 

Bluelines from 1973 of the General Motors Wankel Rotary engine.

 

I just put them up on eBay

 

http://tinyurl.com/GM-Rotary-drawings

 

Pat