X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-pz0-f173.google.com ([209.85.222.173] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4220207 for flyrotary@lancaironline.net; Tue, 13 Apr 2010 14:26:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.222.173; envelope-from=msteitle@gmail.com Received: by pzk3 with SMTP id 3so2019531pzk.26 for ; Tue, 13 Apr 2010 11:26:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:content-type; bh=BY/UIkTVY+Pbe72Iwa2fGR1kosTxQxh2U7tioHCgpRA=; b=VkfgGCYMOJj1XTjkbRJYt6oZaPXWyYzWSdPQzS3jiXK9msnCC3vhBuGzKu3Ba+lkwm s9EJ8JaK3a0UZyghBv4IP/EsVOrSXKa3JGZ1Y10iFj7UxP0+dUGFkgds5IlBkU94oUWl emaCmEvnUBiGgOWv163W1rINNaQiOlVuYxW/g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=dv5LZDQS9bBGbR6FJV0knOdSOH9NohdaOYHpdHKNt/Ie58s8EYtC0vHaj+l5ae6m/q ePEwMSat334j5ZkG3d5TpfU2CMJvG9NKp7RYHuxaEvsL+b+i0AbrOLzRvV+oY8g51km1 9dWw6Tscayiq/K1+ftz/4StzyARPUgvhl57p0= MIME-Version: 1.0 Received: by 10.231.183.195 with HTTP; Tue, 13 Apr 2010 11:26:03 -0700 (PDT) In-Reply-To: References: Date: Tue, 13 Apr 2010 13:26:03 -0500 Received: by 10.115.80.14 with SMTP id h14mr5734040wal.14.1271183163998; Tue, 13 Apr 2010 11:26:03 -0700 (PDT) Message-ID: Subject: Re: [FlyRotary] Re: Tangential muffler From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e64dc932eff6e9048422643a --0016e64dc932eff6e9048422643a Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dwane, Not being an engineer, I usually try to copy something that appears to work for others, adding a few modifications of my own in the process. My only experience with conical mufflers is on 2-stroke engines (go-karts, dirt bikes, etc.). Might be worth a try for someone with access to a dyno and a test stand. Mark On Mon, Apr 12, 2010 at 3:50 PM, Dwayne Parkinson wrote: > Sounds like you've tinkered with mufflers a lot. Have you ever employed = a > conical tail pipe? > > ------------------------------ > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Mon, April 12, 2010 1:43:38 PM > *Subject:* [FlyRotary] Re: Tangential muffler > > Dwane, > > OK, you hold your hand over the end while I rev it up. ;-0 > > Keep in mind that in an earlier muffler design similar to the Moroso > Spiralflow, I had an AN-3 bolt holding the baffle in place. After a few > hours the bolt had gotten so hot that it sagged, resembling a horseshoe. > The rotary's exhaust has proven to be a force to be reconed with. > Hopefully, this will be the last muffler I have to build for a while. > > Mark > > On Mon, Apr 12, 2010 at 1:19 PM, Dwayne Parkinson < > dwayneparkinson@yahoo.com> wrote: > >> This is a very interesting approach. Thanks for posting the pictures. >> It would be very interesting (at least to me) to measure the exhaust ga= s >> pulses at the tail pipe with this design. I wonder if it will normalize= the >> pulses at all so you have an almost steady stream of exhaust gases comin= g >> out of the pipe. >> >> >> >> ------------------------------ >> *From:* Al Gietzen >> *To:* Rotary motors in aircraft >> *Sent:* Mon, April 12, 2010 10:24:07 AM >> *Subject:* [FlyRotary] Re: Tangential muffler >> >> >> >> >> >> Ernest; >> >> >> >> I agree that the geometry of the geometry of the cuts is certainly not >> ideal; and if it were 321SS or similar; yes, I=92d expect it would it to >> disintegrate in about 50 hrs or less. But inconel is very corrosion >> resistant and very strong up to 2000+F. There will be some self-anneali= ng >> of the stresses at 1700F. It would be interesting to know what temp it >> actually gets to because there is some expansion cooling of the gases in= the >> muffler. >> >> >> >> Also it is very tough stuff =96 trying to drill or file inconel will jus= t >> wear out the tools. Holes have to be punched, cut with water jet, or so= me >> other technique. >> >> >> >> It will be interesting to see how it stands up; but I think it has a goo= d >> chance to prove to be quite durable. >> >> >> >> Al >> >> >> >> A grinder will leave two fairly severe 90 degree corners on every edge >> >> of the cut slot. Compounding this is the fact that the side grinder >> >> cuts a circle. The end of each slot will be left with a knife edge >> >> profile pointing back toward the slot. This will create some mean >> >> stress risers. The expectation is that this tube is to live in an >> >> environment that has to be the closest thing to hell on Earth we could >> >> imagine (extreme heat and constant sonic blasts). >> >> >> >> I would have suggested drilling 3/16" holes and connecting them with the >> >> grinder. Unless the inside tube is fabricated different than what I >> >> understand, I can't help but to think that it will have a very short >> >> life. Cracks will start in the corners of each slot, and the tube will >> >> disintegrate. Can it be easily pulled apart so that you could run a >> >> round needle file down both sides of all the slots to round them out? >> >> >> >> -- >> >> Homepage: http://www.flyrotary.com/ >> >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> >> > > --0016e64dc932eff6e9048422643a Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dwane,

Not being an engineer, I usually try to copy some= thing that appears to work for others, adding a few modifications of my own= in the process. =A0My only experience with conical mufflers is on 2-stroke= engines (go-karts, dirt bikes, etc.). =A0Might be worth a try for someone = with access to a dyno and a test stand.

Mark =A0

On Mon, Apr = 12, 2010 at 3:50 PM, Dwayne Parkinson <dwayneparkinson@yahoo.com> wrot= e:
Sounds like you've tinkered with = mufflers a lot. =A0Have you ever employed a conical tail pipe?

From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraf= t <flyr= otary@lancaironline.net>
Sent= : Mon, April 12, 2010 1:43:38 PM
Subject: [FlyRotary] Re: Tan= gential muffler

Dwane,
=A0
OK, you hold your hand over the end while I rev it up.=A0 ;-0=A0
=A0
Keep in mind that in an earlier muffler design similar to the Moroso S= piralflow, I had an AN-3 bolt holding the baffle in place.=A0 After a few h= ours the bolt had gotten so hot that it sagged, resembling a horseshoe.=A0 = The rotary's exhaust has proven to be a force to be reconed with.=A0 Ho= pefully, this will be the last muffler I have to build for a while.
=A0
Mark

On Mon, Apr 12, 2010 at 1:19 PM, Dwayne Parkinso= n <dwayneparkinson@yahoo.com> wrote= :
This is a very interesting approach. =A0Thanks for posting the picture= s. =A0It would be very interesting (at least to me) to measure the exhaust = gas pulses at the tail pipe with this design. =A0I wonder if it will normal= ize the pulses at all so you have an almost steady stream of exhaust gases = coming out of the pipe.



From: Al Gietzen <ALVentur= es@cox.net>
To: Ro= tary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, April 12, 2010 10= :24:07 AM
Subject: [FlyRo= tary] Re: Tangential muffler

=A0

=A0

Ernest;<= /span>

=A0

I agree that the geometry of the geometry of the cuts is certa= inly not ideal; and if it were 321SS or similar; yes, I=92d expect it would= it to disintegrate in about 50 hrs or less.=A0 But inconel is very corrosi= on resistant and very strong up to 2000+F.=A0 There will be some self-annea= ling of the stresses at 1700F.=A0 It would be interesting to know what temp= it actually gets to because there is some expansion cooling of the gases i= n the muffler.

=A0

Also it is very tough stuff =96 trying to drill or file incone= l will just wear out the tools.=A0 Holes have to be punched, cut with water= jet, or some other technique.

=A0

It will be interesting to see how it stands up; but I think it= has a good chance to prove to be quite durable.

=A0

Al

=A0

A grinde= r will leave two fairly severe 90 degree corners on every edge

of the c= ut slot.=A0 Compounding this is the fact that the side grinder

cuts a c= ircle.=A0 The end of each slot will be left with a knife edge

profile = pointing back toward the slot.=A0 This will create some mean =

stress r= isers.=A0 The expectation is that this tube is to live in an =

environm= ent that has to be the closest thing to hell on Earth we could

imagine = (extreme heat and constant sonic blasts).

=A0

I would = have suggested drilling 3/16" holes and connecting them with the

grinder.= =A0 Unless the inside tube is fabricated different than what I

understa= nd, I can't help but to think that it will have a very short

life.=A0= Cracks will start in the corners of each slot, and the tube will

disinteg= rate. Can it be easily pulled apart so that you could run a <= /p>

round ne= edle file down both sides of all the slots to round them out?=

=A0

--

Homepage:=A0 ht= tp://www.flyrotary.com/

Archive and UnSub:=A0=A0 http://mail.lancaironline.net:81= /lists/flyrotary/List.html





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