X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2200388 for flyrotary@lancaironline.net; Thu, 26 Jul 2007 10:16:31 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20070726141553.JFRI1393.fed1rmmtao106.cox.net@fed1rmimpo02.cox.net> for ; Thu, 26 Jul 2007 10:15:53 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id UEFt1X00N1xAn3c0000000; Thu, 26 Jul 2007 10:15:53 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: bench flowtest Date: Thu, 26 Jul 2007 07:17:45 -0800 Message-ID: <000001c7cf98$1e896d50$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C7CF55.10689E50" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C7CF55.10689E50 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: [FlyRotary] Re: bench flowtest =20 WRJJRS@aol.com wrote:=20 Kevin, With rotaries they have found that a constantly expanding exhaust helps = keep the pulse moving. It also keeps the LOUD moving.=20 Okay, This brings to mind a question: how fast are those pulse moving? It's pretty easy to figure out how long between pulses for any given=20 RPM, but it would be nice to know how far down the pipe a puff of=20 exhaust gets before the next one starts chasing it. Anyone here already = know this? (Yes, I know I can search for it on the net - well, this is = my=20 first attempt.) Best Regards, Dale R. Dale; I may have missed if someone answered this already; the shock wave = travels at the speed of sound in the air at EG temps - that would be about 2700 = fpm. (http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe.html). Since it = is traveling in a gas that has an average velocity of some number depending = on the volume of exhaust and the diameter of the pipe; add that on. Al -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0001_01C7CF55.10689E50 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Subject: [FlyRotary] Re: bench flowtest

WRJJRS@aol.com wrote: =

Kevin,

With rotaries they have found that a = constantly expanding exhaust helps keep the pulse moving. It also keeps the LOUD = moving.

Okay, This brings to mind a question: = how fast are those pulse moving?
It's pretty easy to figure out how long between pulses for any given =
RPM, but it would be nice to know how far down the pipe a puff of
exhaust gets before the next one starts chasing it. Anyone here = already
know this? (Yes, I know I can search for it on the net - well, = this is my
first attempt.)
Best Regards,
Dale R.

Dale;

I may have missed if someone answered this already; the shock wave travels = at the speed of sound in the air at EG temps – that would be about 2700 = fpm.

(http://hyperph= ysics.phy-astr.gsu.edu/hbase/sound/souspe.html). Since it is traveling in a gas that has an average velocity of some = number depending on the volume of exhaust and the diameter of the pipe; add = that on.

Al

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Homepage:  http://www.flyrotary.com/

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