Return-Path: <13brv3@bellsouth.net> Received: from imf16aec.mail.bellsouth.net ([205.152.59.64] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2900040 for flyrotary@lancaironline.net; Sun, 21 Dec 2003 20:57:24 -0500 Received: from rad ([68.212.7.74]) by imf16aec.mail.bellsouth.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20031222015723.BDWZ1884.imf16aec.mail.bellsouth.net@rad> for ; Sun, 21 Dec 2003 20:57:23 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Dumb intake question Date: Sun, 21 Dec 2003 19:57:24 -0600 Message-ID: <028a01c3c82e$f1b30d00$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_028B_01C3C7FC.A7189D00" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_028B_01C3C7FC.A7189D00 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable What happens is when a Finite Amplitude Wave (FAW) hits a change in cross-sectional area (like an opening from your tube to the atmoshpere = or a plenium - or a decrease to a closed tube) energy is reflected back down = the tube. The amount depends on the extent of cross section change, but = opening to the atmosphere reflects most of the energy. If the cross sectional = area it sees is Larger then a FAW wave of the opposite type is reflected. If = the cross sectional area is smaller, a FAW wave of the same type is = reflected.=20 =20 =20 Hi Ed,=20 =20 Thanks for an explanation that was a clear as it could possibly be. Now that you have confirmed that the change of cross sectional area is what triggers the bounce, I can get back to a question that I asked you a few months ago (Kelly just asked the same one). =20 =20 Back when Eddie was first being discussed, I asked if I could extend the runner ahead of the TB, and have it count as part of the tuned assembly. = At the time, you said no, that it had to be after the TB. Is that your = final answer :-) =20 =20 If tuning is possible prior to the TB, then a short manifold will work great, and offer easy tuning of the length. =20 =20 Thanks, Rusty (new cowl looks muuuuuch better) ------=_NextPart_000_028B_01C3C7FC.A7189D00 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
  What happens is when a = Finite=20 Amplitude Wave (FAW) hits a change in cross-sectional area (like an = opening from=20 your tube to the atmoshpere or a plenium - or a decrease to a closed = tube)=20 energy is reflected back down the tube. The amount depends on the extent = of=20 cross section change, but opening to the atmosphere reflects most of the = energy.=20   If the cross sectional area it sees is Larger then a FAW wave of = the=20 opposite type is reflected.  If the cross sectional area is = smaller, a FAW=20 wave of the same type is reflected. 
 
 
Hi Ed,=20
 
Thanks=20 for an explanation that was a clear as it could possibly be.  Now = that you=20 have confirmed that the change of cross sectional area is what triggers = the=20 bounce, I can get back to a question that I asked you a few months ago = (Kelly=20 just asked the same one). 
 
Back=20 when Eddie was first being discussed, I asked if I could extend the = runner ahead=20 of the TB, and have it count as part of the tuned = assembly.  At the=20 time, you said no, that it had to be after the TB.  Is that your = final=20 answer :-)  
 
If=20 tuning is possible prior to the TB, then a short manifold will work = great, and=20 offer easy tuning of the length. 
 
Thanks,
Rusty=20 (new cowl looks muuuuuch = better)
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