X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail17.syd.optusnet.com.au ([211.29.132.198] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTPS id 1006452 for flyrotary@lancaironline.net; Sat, 18 Jun 2005 18:54:09 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.198; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-0-190.dsl.nsw.optusnet.com.au [220.236.0.190]) by mail17.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j5IMrL7E009627 for ; Sun, 19 Jun 2005 08:53:22 +1000 Message-ID: <004201c57459$47f272f0$be00ecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: small muffler suggestions for single rotor? Date: Sun, 19 Jun 2005 08:58:45 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003F_01C574AD.1956CB90" 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 This is a multi-part message in MIME format. ------=_NextPart_000_003F_01C574AD.1956CB90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageAnother way to make an exhaust fit an unusual shape is to stack = more than one exhaust - making them out of square would help in this = regard. The outlet of one could be directly over the inlet of the other = and could be made the same area as the square tube. Square tube has a greater surface area and the exhaust scrubbing the = side walls converts the noise into heat. Then again that's more heat under the cowl! Just a couple of ideas to throw around! George (down under) Would the inlet in the center of the can with a small outlet on each = end work? Georges B. Good thought, but I'm not the one who would know. As I recall, this = is a very familiar concept in RC engine mufflers. =20 Rusty=20 ------=_NextPart_000_003F_01C574AD.1956CB90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Another way to make an exhaust fit an unusual shape is to = stack=20 more than one exhaust - making them out of square would help in = this=20 regard. The outlet of one could be directly over the inlet of the other = and=20 could be made the same area as the square tube.
 
Square tube has a greater surface area and the exhaust scrubbing = the side=20 walls converts the noise into heat.
 
Then again that's more heat under the cowl!
Just a couple of ideas to throw around!
George (down under)

Would the inlet in the center of the can with a = small outlet=20 on each end work?
Georges B.

Good thought, but I'm not the = one who would=20 know.  As I recall, this is a very familiar concept in RC engine=20 mufflers.  

Rusty =

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