Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 776256 for flyrotary@lancaironline.net; Tue, 08 Mar 2005 22:49:07 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.rr.com [24.74.185.127]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j293mILw024219 for ; Tue, 8 Mar 2005 22:48:19 -0500 (EST) Message-ID: <000a01c5245a$d9a960e0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Anechoic Muffler Date: Tue, 8 Mar 2005 22:48:26 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C52430.F09C9170" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C52430.F09C9170 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I would love to weld one up for you over the weekend Tom, but can't for = two reasons: 1. Ain't going to be here - going flying to Florida to the Leeward = Ranch Airpark RV Flyin. 2. I don't weld - always wanted to learn how, but have not made it yet. Ed A ----- Original Message -----=20 From: Tom=20 To: Rotary motors in aircraft=20 Sent: Tuesday, March 08, 2005 10:08 PM Subject: [FlyRotary] Re: Anechoic Muffler Ed Anderson wrote:=20 Ok, I've shown you mine now its your turn to show me yours {:>) Ed A I remember an older brother saying that to a neighbor girl. =20 Ok, here it is revealed to the world. Ed, you introduced me to the = DIE concept of the intake system, where essentially pulses are reflected = back toward the intake port. I later read more about this when = looking up plenums and they recommended having a flat wall for these = pulses to be reflected. My latest iteration for an 'anechoic muffler' = is the opposite. The exhaust header/muffler is shaped like a V laying = on it's side, as viewed from the end of the motor. The exhaust from = the ports is shot into it between these walls and hopefully attenuated = as it narrows. At both ends of this thing you have end plates. At = one or both ends of this thing you have an exhaust port for the gasses = to flow out. The specific angle of the v probably depends on wave = characteristics and needs to be putzed with to optimize. It's maybe = best constructed from thicker material to better deal with the pulses. =20 Due to interference from the motor mount you'de probably need runners = and place this outside the mount. In this case, you don't necessarily = need to orient the V on its side, you can make your feeding exhaust = pipes turn 90 degrees downward into a properly oriented V and catch all = the apex seal debris for inspection. Hey, make it protrude downward = from the bottom-center of your cowl and let the outside airstream cool = it.=20 Other variations, have smaller individual v-chambers per exhaust = port. With this you have more flexibility on their placement. Then = you may or may not wish to join the exhaust gas outputs into a common = exhaust pipe. =20 Thats the basic concept. Can you weld one of these over the = weekend and give it a spin? Tom Tugan -------------------------------------------------------------------------= ----- Celebrate Yahoo!'s 10th Birthday!=20 Yahoo! Netrospective: 100 Moments of the Web ------=_NextPart_000_0007_01C52430.F09C9170 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I would love to weld one up for you = over the=20 weekend Tom, but can't  for two reasons:
 
1.  Ain't going to be here - going = flying to=20 Florida to the Leeward Ranch Airpark RV Flyin.
2.  I don't weld - always wanted = to learn how,=20 but have not made it yet.
 
Ed A
----- Original Message -----
From:=20 Tom
Sent: Tuesday, March 08, 2005 = 10:08=20 PM
Subject: [FlyRotary] Re: = Anechoic=20 Muffler

Ed Anderson <eanderson@carolina.rr.com&g= t;=20 wrote:=20
 
  Ok, I've shown you mine now = its your turn=20 to show me yours {:>)
Ed = A
I remember an older brother saying that to a neighbor=20 girl.   
 
 
Ok, here it is revealed to the world.    Ed, you=20 introduced me to the DIE concept of the intake system, where = essentially=20 pulses are reflected back toward the intake port.    I = later=20 read more about this when looking up plenums and they recommended = having a=20 flat wall for these pulses to be reflected.    My = latest=20 iteration for an 'anechoic muffler' is the opposite.  The exhaust = header/muffler is shaped like a V laying on it's side, as viewed from = the end=20 of the motor.    The exhaust from the ports is shot = into it=20 between these walls and hopefully attenuated as it=20 narrows.    At both ends of this thing you have end=20 plates.   At one or both ends of this thing you have an = exhaust port=20 for the gasses to flow out.      The specific = angle=20 of the v probably depends on wave characteristics and needs to be = putzed with=20 to optimize.    It's maybe best constructed from = thicker=20 material to better deal with the pulses. 
 
Due to interference from the motor mount you'de probably need = runners and=20 place this outside the mount.  In this case, you don't = necessarily need=20 to orient the V on its side, you can make your feeding exhaust pipes = turn 90=20 degrees downward into a properly oriented V and catch all the apex = seal debris=20 for inspection.   Hey, make it protrude downward from the=20 bottom-center of your cowl and let the outside airstream cool it. =
 
Other variations,  have smaller individual v-chambers per = exhaust=20 port.   With this you have more flexibility on their=20 placement.   Then you may or may not wish to join the = exhaust=20 gas outputs into a common exhaust pipe.  
 
Thats the basic concept.      Can you weld = one of=20 these over the weekend and give it a spin?
 
Tom Tugan

 

Celebrate Yahoo!'s 10th Birthday!
Yahoo! = Netrospective: 100=20 Moments of the Web ------=_NextPart_000_0007_01C52430.F09C9170--