X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3879610 for flyrotary@lancaironline.net; Thu, 08 Oct 2009 19:07:10 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao106.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20091008230634.UGQJ21192.fed1rmmtao106.cox.net@fed1rmimpo02.cox.net> for ; Thu, 8 Oct 2009 19:06:34 -0400 Received: from BigAl ([72.192.133.78]) by fed1rmimpo02.cox.net with bizsmtp id qP6Z1c0091hf1Cg04P6ZbR; Thu, 08 Oct 2009 19:06:33 -0400 X-VR-Score: -100.00 X-Authority-Analysis: v=1.0 c=1 a=Ia-xEzejAAAA:8 a=HZJGGiqLAAAA:8 a=Hl1Gy0H5AAAA:8 a=-BP97Xo4kkAM0pBiOl0A:9 a=qTmTU0p45kUk7taLcZKLs8qdx0AA:4 a=EzXvWhQp4_cA:10 a=HeoGohOdMD0A:10 a=039ozccocCeulRynvCAA:9 a=q5larNxS5jnZoAg_HSoA:7 a=xvs3o9mjQlPKKgYT0SquIQiuWwEA:4 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Your muffler Date: Thu, 8 Oct 2009 16:06:53 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01CA4831.5A6BC4D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 Importance: Normal Thread-Index: AcpIXFmLNa6f0sS+Q++2wXeafiMy4AAFkRsg In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0005_01CA4831.5A6BC4D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable George; =20 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.=20 =20 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. =20 Your depiction of the idealized sounds waves going axially; ah-h, well; maybe/maybe not:-). =20 Al G =20 -----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 =20 Kelly There you go matey. All off the shelf SS cones and tube. George ( down under) ----- Original Message -----=20 From: Kelly Troyer =20 To: Rotary motors in aircraft=20 Sent: Thursday, October 08, 2009 9:32 PM Subject: [FlyRotary] Your muffler =20 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...... =20 =20 Thanks, -- Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 =20 -------------- Original message from "George Lendich" : --------------=20 > Ed,=20 > Cones are the GO.=20 >=20 > Any bare edge will take a battering from the heat and shock waves. = Cones=20 > formed back to back eliminate any edges.=20 >=20 > There must be supporting structure for the cones, I've used 1/4" solid = > round bar welded into the exhaust skin.=20 > George (down under)=20 ------=_NextPart_000_0005_01CA4831.5A6BC4D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

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

 

Kelly

There you go matey. All off = the shelf SS cones and tube.

George ( down = under)

=

----- Original Message = -----

From: Kelly Troyer =

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)

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