X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from QMTA09.emeryville.ca.mail.comcast.net ([76.96.30.96] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3881573 for flyrotary@lancaironline.net; Sat, 10 Oct 2009 09:27:33 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.96; envelope-from=wschertz@comcast.net Received: from OMTA10.emeryville.ca.mail.comcast.net ([76.96.30.28]) by QMTA09.emeryville.ca.mail.comcast.net with comcast id r1Hk1c0080cQ2SLA91Sztw; Sat, 10 Oct 2009 13:26:59 +0000 Received: from WschertzPC ([71.57.77.95]) by OMTA10.emeryville.ca.mail.comcast.net with comcast id r1Sw1c00523NHuF8W1SxMH; Sat, 10 Oct 2009 13:26:59 +0000 Message-ID: <0E4A183832E8434A86F97903D5CFC708@WschertzPC> From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: YO-3A design muffler Date: Fri, 9 Oct 2009 15:19:53 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0041_01CA48F3.F3F0D560" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6001.18000 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0041_01CA48F3.F3F0D560 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Where can we see a drawing of this? Bill Schertz KIS Cruiser #4045 N343BS Phase I testing ----- Original Message -----=20 From: Mike Wills=20 To: Rotary motors in aircraft=20 Sent: Friday, October 09, 2009 12:05 PM Subject: [FlyRotary] Re: Your muffler OK George, my memory is now jogged having seen your drawing. I liked = the design when I saw it the first time but discounted it for my = application because I couldnt see a good way to make any muffler with a = tangential entry fit my airframe. This is the same reason I passed on = Al's proven muffler design. I think the use of cooling airflow introduced into the muffler makes a = lot of sense and this is something your design has in common with the = YO-3A muffler I've been talking about. I believe the YO-3A design would = prove superior by virtue of the greatly increased volume of the muffler = and the use of absorptive materials. Of course until someone builds one and tries it who knows if it will = hold up to the abusive exhaust output of a rotary. But the YO-3A design = does have the advantage of being flight proven in a pretty tough = environment - low altitude recon in Vietnam. Your muffler design (or Al's) is a winner if the goal is to keep the = muffler within the confines of the cowl. My cowl is already too tight = without a muffler in it. Mike Wills RV-4 N144MW=20 ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Thursday, October 08, 2009 9:18 PM Subject: [FlyRotary] Re: Your muffler Al, Not tested yet, but have one almost complete for the single. The cones are there to stop the sound waves having a direct line of = sight out the rear end, the sound waves will be going all over the place = within the exhaust and I tried to replicate that with the zig zaggy = lines. There is no restriction as the area around the back to back cones, = is equal to the area of the 2" exhaust manifold area. However I do take your point on swirl restriction, but I don't see a = problem as it will swirl out the end, whereas sound waves travel in a = straight line ( I think). Bill did have me put in a reflector plate = opposite the incoming exhaust, but I don't know if this will interrupt = the swirl motion, I suspect it might. The reflector plate is on the LHS = of the parts count - photo attached. George ( down under) 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.=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. 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 -----=20 From: Kelly Troyer=20 To: Rotary motors in aircraft=20 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=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=20 > round bar welded into the exhaust skin.=20 > George (down under)=20 -------------------------------------------------------------------------= --- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0041_01CA48F3.F3F0D560 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Where can we see a drawing of = this?
Bill Schertz
KIS Cruiser #4045
N343BS
Phase I = testing
----- Original Message -----
From:=20 Mike = Wills
Sent: Friday, October 09, 2009 = 12:05=20 PM
Subject: [FlyRotary] Re: Your=20 muffler

OK George, my memory is now jogged = having seen=20 your drawing. I liked the design when I saw it the first time but = discounted=20 it for my application because I couldnt see a good way to make = any=20 muffler with a tangential entry fit my airframe. This is the same = reason I=20 passed on Al's proven muffler design.
 
I think the use of cooling airflow = introduced=20 into the muffler makes a lot of sense and this is something your = design has in=20 common with the YO-3A muffler I've been talking about. I believe the = YO-3A=20 design would prove superior by virtue of the greatly increased volume = of the=20 muffler and the use of absorptive materials.
 
Of course until someone builds one = and tries it=20 who knows if it will hold up to the abusive exhaust output of a = rotary. But=20 the YO-3A design does have the advantage of being flight proven in a = pretty=20 tough environment - low altitude recon in Vietnam.
 
Your muffler design (or Al's) = is a winner if=20 the goal is to keep the muffler within the confines of the cowl. My = cowl is=20 already too tight without a muffler in it.
 
Mike Wills
RV-4 N144MW 
----- Original Message -----
From:=20 George=20 Lendich
To: Rotary motors in = aircraft=20
Sent: Thursday, October 08, = 2009 9:18=20 PM
Subject: [FlyRotary] Re: Your = muffler

Al,
Not tested yet, but have one almost = complete=20 for the single.
 
The cones are there to stop the = sound=20 waves having a direct line of sight out the rear end, the sound = waves=20 will be going all over the place within the exhaust and I tried to = replicate=20 that with the zig zaggy lines.
 
There is no restriction as the area = around the=20 back to back cones, is equal to the area of the 2" exhaust=20 manifold area.
 
However I do take your point on = swirl=20 restriction, but I don't see a problem as it will swirl out the end, = whereas=20 sound waves travel in a straight line ( I think).  Bill did have me put in a reflector plate opposite the = incoming=20 exhaust, but I don't know if this will interrupt the swirl motion, I = suspect=20 it might. The reflector plate is on the LHS of the parts count = - photo=20 attached.
 
George ( down under)

George;

 

Nice=20 design.  Has anyone run one of these yet.

My = concern with=20 the tangential muffler is something called =91swirl flow = choking=92 =96=20 discovered in connection with a similar attempt with gas turbine = exhaust.=20  High circumferential velocity tends to keep the flow from = moving out=20 the end, and consequent pressure buildup.  I don=92t know = whether it=20 applies to the pulsed flow, but it might, and your conical = restriction=20 toward the outlet could make it worse.

 

To = avoid that=20 possibility in my tangential muffler I added internal vanes at a = 45 degree=20 angle opposite the ports, and extended the header pipes into = muffler to a=20 squared end. Disrupts the circumferential flow and helps direct = the=20 exhaust toward the exit.

 

Your = depiction=20 of the idealized sounds waves going axially; ah-h, well; = maybe/maybe=20 notJ.

 

Al=20 G

 

-----Original=20 Message-----
From: Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George=20 Lendich
Sent: = Thursday,=20 October 08, 2009 1:14 PM
To: Rotary motors in=20 aircraft
Subject:=20 [FlyRotary] Re: Your muffler

 

Kelly

There you go=20 matey. All off the shelf SS cones and = tube.

George ( down=20 under)

-----=20 Original Message -----

From: Kelly = Troyer=20

To: Rotary motors in = aircraft=20

Sent:=20 Thursday, October 08, 2009 9:32 PM

Subject:=20 [FlyRotary] Your muffler

 

 =20 George,

   Do you=20 have a photo or drawing available of your muffler = design..........I seem=20 to

remember seeing=20 some design info in the past but do not know where to find=20 it......

 

 

Thanks,

--
Kelly Troyer
"Dyke = Delta"_13B ROTARY=20 Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil = Manifold=20


 

--------------=20 Original message from "George Lendich" = <lendich@aanet.com.au>:=20 --------------


> Ed,
> Cones are the GO. =
>
> Any bare edge will take a battering from the = heat=20 and shock waves. Cones
> formed back to back eliminate = any=20 edges.
>
> There must be supporting structure = for the=20 cones, I've used 1/4" solid
> round bar welded into the = exhaust=20 skin.
> George (down under)=20 =

--
Homepage:  http://www.flyrotary.com/
Archive = and=20 UnSub:  =20 = http://mail.lancaironline.net:81/lists/flyrotary/List.html
------=_NextPart_000_0041_01CA48F3.F3F0D560--