X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=H+OlPNQi c=1 sm=1 tr=0 a=rCc/Pk3oV6av6DuqWjX5/w==:117 a=kloI1ui9B+OOwk393D4IlA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x7bEGLp0ZPQA:10 a=A-0mRrAPPO4A:10 a=MeAgGD-zjQ4A:10 a=r77TgQKjGQsHNAKrUKIA:9 a=pGLkceISAAAA:8 a=hOpmn2quAAAA:8 a=Ia-xEzejAAAA:8 a=eRLigfuSAAAA:8 a=xPyZ54XvAAAA:8 a=meJbv3C4AAAA:8 a=7g1VtSJxAAAA:8 a=FEd23BpTAAAA:8 a=uoJSKhK-mcTBAAYKtTcA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=N5n9HDkQ76oA:10 a=oOz5yF6qyDwA:10 a=gvSQh4r-fQ0A:10 a=4PR2P7QzAAAA:8 a=6hJUURUM9aBubIpw0OUA:9 a=rmyJCyVHzitdaZWV:21 a=_W_S_7VecoQA:10 a=GyA-uvUxXSCciAkwuKQO:22 a=Urk15JJjZg1Xo0ryW_k8:22 a=BfhXYjFvZD4iae-mNffo:22 a=LQCduUwlY3eUW_MavTj7:22 a=grOzbf7U_OpcSX4AJOnl:22 a=80WO7EPaVbmEDwVs73Zs:22 a=4dqwQCo7Po2mVW515mGf:22 From: "Charlie England ceengland7@gmail.com" Received: from mail-yw1-f47.google.com ([209.85.161.47] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 13198264 for flyrotary@lancaironline.net; Wed, 20 Nov 2019 13:25:19 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.47; envelope-from=ceengland7@gmail.com Received: by mail-yw1-f47.google.com with SMTP id j137so294319ywa.12 for ; Wed, 20 Nov 2019 10:25:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language; bh=Zbq+9emWLe8YnljisZDGTwJoeX07sOoOOWYWT3LBZjw=; b=s2vG3n5AGtCpZaR3rEVu2WN35zQD5TDMN4DybJhAaA41HO+bAJYfZpAUXGaTT+nW4O 6lKuTEwbIKw3qgdaR7gPRC00VDRdy584LOsqSo7lq3jdkAY7O8EO2icbVXSXOksXATb8 w8BjSAPCPrJBfWgdFYNi9+CRz91fkKlScDEUSbPPRL0HPOU6LSyvdB5uoJs7iuuGkP4g 67XR7jy6QX0GN0es9y1sCPt+mMOh+PdgY7P7tRjBcpRba1A3wNJdrYrIFlW12rR2JZBD w3UsFcBoTHWwkCVK04of9hl+6gDIx1PrIvVLdbE0vVcXUM0qKbghXqB9SPD/xMS9r5ho ROsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=Zbq+9emWLe8YnljisZDGTwJoeX07sOoOOWYWT3LBZjw=; b=DCbBpOSJ3fAcp6gUQBNzrRJ+0ezaYgXJpZlWgwt1xxWeQR8UK/GJG9bBoo7CL4dSVh l5tKbIFYgPtRCo5rA6IGcz/fXXOE9+HsbBCEj48z1OZgkAve2bPButOjIzqTMrkH+hOR 6Ve8cmljT7J1cRfNJhgSnBumIa2sQC8h2MmHLrN5+/1lFeC2Kx+n5TIxoYWtrTWDiQRY w2Dsws2DCr5QHQoxPJZaygQYHEVo9ggluXKA+01DtBTlY6cNTixjbLR1e2tXwO3KeMFf yjPHaYL8otHco3umq1LCUSQzU1YSJ2HEsGczlofdlG8LhdpGu7HLLkhLavEDXW5QeNz1 tsYw== X-Gm-Message-State: APjAAAXjn/IIMSmx798EAnNdihSMb/WoeD0+AAM1LX9vWXStkWt/f6j+ PuK4g+u4u386Vxt8D13Xq5jcEMhA X-Google-Smtp-Source: APXvYqxDaUVQ696NTiyMaLrIcCTS5a0T0vx/FMJ+xX/aJz00YD7BnOAv6m0YK0AhtlcYdMtqhM8Sew== X-Received: by 2002:a81:2857:: with SMTP id o84mr2655663ywo.162.1574274300846; Wed, 20 Nov 2019 10:25:00 -0800 (PST) Return-Path: Received: from [192.168.10.246] (mobile-166-173-250-183.mycingular.net. [166.173.250.183]) by smtp.googlemail.com with ESMTPSA id t15sm82071ywf.69.2019.11.20.10.24.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Nov 2019 10:25:00 -0800 (PST) Subject: Re: [FlyRotary] Re: Mufflers To: Rotary motors in aircraft References: Message-ID: Date: Wed, 20 Nov 2019 12:24:59 -0600 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------5A715B17D33FAD8B7B7655D5" Content-Language: en-US X-Antivirus: Avast (VPS 191119-0, 11/19/2019), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. --------------5A715B17D33FAD8B7B7655D5 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit On 11/20/2019 10:22 AM, David Leonard wdleonard@gmail.com wrote: > Marcus, > I am really glad you brought up the Mistral incident, as I have been > meaning to mention it too.  For what it's worth, my experience with > mufflers confirms what many other have said. The exhaust environment > in rotary aircraft is very extreme and component  failure can be > catastrophic.  I have tried several types of high end packing, and > nothing survives more than a few hours.  300 series stainless > tolerates the heat, but any welds on thin stainless have limited > life.  I would be very suspicious of anything with complex innards > like the Aero Turbine 2525.  Doing what Jeff Whaley did by adding > perforations should be a must-do in my opinion. > > Dave Leonard > > On Wed, Nov 20, 2019 at 5:59 AM Marcus Wiese cardmarc@charter.net > > wrote: > > Just remember the Mistral muffler event. The muffler caused the > Piper Arrow  (?) with their rotary to crash after the internals > blocked the outlet and led to power loss. It may have partially > led to their withdrawal from the engine/PSRU market. To all our loss. > M > > Sent from my iPad > >> On Nov 20, 2019, at 12:28 AM, Matt Boiteau mattboiteau@gmail.com >> > > wrote: >> >>  >> This is the Aero Exhaust 2525XL diagram. I have one, but left it >> in Canada. Will bring it back with me in Jan to try at taming the >> exhaust again. >> >> >> >> - Matt Boiteau >>> >>> On 2019-11-19 3:23:50 PM, Charlie England ceengland7@gmail.com >>> >> > wrote: >>> >>> >>> >>> On Mon, Nov 18, 2019 at 11:57 PM Andrew Martin >>> andrew@martinag.com.au >>> >> > wrote: >>> >>> >>> Kelly, I would if I had some, really did not expect it to >>> work as I deviated from the design a bit. Will be back at >>> airport on weekend to take photo, too late for construction >>> photo. But nothing to it. >>> >>> I read about the idea by Gary Schwarz in this thread >>> , >>> post #7 , post #58 for his testing and post #142 sums up his >>> findings. >>> Someone on here may know him as he was doing it for a >>> rotary. Mine is much shorter than his drawing below due to >>> space constraints but the theory works. >>> edit: Ahh!!! deleted his picture as too big to post. it is >>> in his post #7 mentioned above though. >>> Andrew >>> >>> That looks a lot like a simplified version (one less turn) of a >>> standard automotive muffler. >>> https://auto.howstuffworks.com/muffler3.htm >>> The Aeroturbine tries to achieve similar effect (without the >>> flow reversals) by using venturi effect to suck part of the >>> exhaust around and then back into the central tube. >>> >>> Charlie >>> >> <2525.JPG> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html > The caution about potential blockage is warranted on any engine, but obviously a greater danger with the rotary's powerful pulses. It's worth mentioning that the Renesis' exhaust should be significantly less 'violent' than a 13B, for a couple of reasons. The exhaust has to take a 'sharp right' as it exits the combustion chamber, which helps break up the shock wave a bit, but even more importantly, the exhaust port, instead of 'snapping open' like a piston ported two stroke, opens more gradually, more like a conventional poppet valve in a piston engine. As a FWIW on the Aeroturbine: I don't have a 2525XL to examine, but the regular 2525 (minus the 1st chamber of the XL) is a 'straight through' design. That cone on the input end is open. Drawing of the guts is on the Aeroturbine web site. https://aeroexhaust.com/i-30497606-aero-exhaust-turbine-at2525-performance-muffler-2-5-inside-diameter-necks-aggressive-sound.html IIRC, Tracy's been flying one on the 20B powered RV-8 for a number of years. That's what motivated me to purchase one, but it hasn't seen any exhaust gas yet. Charlie --------------5A715B17D33FAD8B7B7655D5 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit
On 11/20/2019 10:22 AM, David Leonard wdleonard@gmail.com wrote:
Marcus,
I am really glad you brought up the Mistral incident, as I have been meaning to mention it too.  For what it's worth, my experience with mufflers confirms what many other have said.  The exhaust environment in rotary aircraft is very extreme and component  failure can be catastrophic.  I have tried several types of high end packing, and nothing survives more than a few hours.  300 series stainless tolerates the heat, but any welds on thin stainless have limited life.  I would be very suspicious of anything with complex innards like the Aero Turbine 2525.  Doing what Jeff Whaley did by adding perforations should be a must-do in my opinion.

Dave Leonard

On Wed, Nov 20, 2019 at 5:59 AM Marcus Wiese cardmarc@charter.net <flyrotary@lancaironline.net> wrote:
Just remember the Mistral muffler event. The muffler caused the Piper Arrow  (?) with their rotary to crash after the internals blocked the outlet and led to power loss. It may have partially led to their withdrawal from the engine/PSRU market. To all our loss.
M

Sent from my iPad

On Nov 20, 2019, at 12:28 AM, Matt Boiteau mattboiteau@gmail.com <flyrotary@lancaironline.net> wrote:


This is the Aero Exhaust 2525XL diagram. I have one, but left it in Canada. Will bring it back with me in Jan to try at taming the exhaust again.



- Matt Boiteau

On 2019-11-19 3:23:50 PM, Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:



On Mon, Nov 18, 2019 at 11:57 PM Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:

Kelly, I would if I had some, really did not expect it to work as I deviated from the design a bit. Will be back at airport on weekend to take photo, too late for construction photo. But nothing to it.

I read about the idea by Gary Schwarz in this thread, post #7 , post #58 for his testing and post #142 sums up his findings.
Someone on here may know him as he was doing it for a rotary. Mine is much shorter than his drawing below due to space constraints but the theory works.
edit: Ahh!!! deleted his picture as too big to post. it is in his post #7 mentioned above though.
Andrew

That looks a lot like a simplified version (one less turn) of a standard automotive muffler.
The Aeroturbine tries to achieve similar effect (without the flow reversals) by using venturi effect to suck part of the exhaust around and then back into the central tube.

Charlie

 
<2525.JPG>
--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html
The caution about potential blockage is warranted on any engine, but obviously a greater danger with the rotary's powerful pulses.

It's worth mentioning that the Renesis' exhaust should be significantly less 'violent' than a 13B, for a couple of reasons. The exhaust has to take a 'sharp right' as it exits the combustion chamber, which helps break up the shock wave a bit, but even more importantly, the exhaust port, instead of 'snapping open' like a piston ported two stroke, opens more gradually, more like a conventional poppet valve in a piston engine.

As a FWIW on the Aeroturbine: I don't have a 2525XL to examine, but the regular 2525 (minus the 1st chamber of the XL) is a 'straight through' design. That cone on the input end is open. Drawing of the guts is on the Aeroturbine web site.
https://aeroexhaust.com/i-30497606-aero-exhaust-turbine-at2525-performance-muffler-2-5-inside-diameter-necks-aggressive-sound.html

IIRC, Tracy's been flying one on the 20B powered RV-8 for a number of years. That's what motivated me to purchase one, but it hasn't seen any exhaust gas yet.

Charlie
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