X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from [201.225.225.168] (HELO cwpanama.net) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1876669 for flyrotary@lancaironline.net; Thu, 01 Mar 2007 13:06:41 -0500 Received-SPF: none receiver=logan.com; client-ip=201.225.225.168; envelope-from=rijakits@cwpanama.net Received: from [201.224.94.164] (HELO usuario5ebe209) by frontend2.cwpanama.net (CommuniGate Pro SMTP 4.2.10) with SMTP id 103285397 for flyrotary@lancaironline.net; Thu, 01 Mar 2007 13:31:37 -0500 Message-ID: <003a01c75c2c$34fb7680$a45ee0c9@usuario5ebe209> From: "Thomas y Reina Jakits" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: diffusers Date: Thu, 1 Mar 2007 13:05:31 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0037_01C75C02.4ABFC400" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0037_01C75C02.4ABFC400 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable John, I agree, the way your cowl looks, it does not make sense (to me....) to reduce = the intake size the way you indicate. If you were to reduce the intake from the outside in, including = narrowing the cowl, then discuss the size. As is, might as well use it, the frontal area is the same, whether it is = open or closed off. Thomas ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Thursday, March 01, 2007 9:53 AM Subject: [FlyRotary] Re: diffusers John, I would go with the 22 1/4 sq inches. For these reasons: 1. Your engine may produce more power than the one I run with - = requiring more heat rejection. 2. It is easier to neck down the opening (than widen it) if it turns = out you have more than what is necessary - or do nothing 3. My cowl exit area is probably a bit larger than most which may = produce less back pressure enabling smaller opening to flow more air. Ball up your fist and see if you can stick it through the narrowest = opening - it should just almost go (that is if you have the same size = hands I do {:>)) How's that for a standard of measure? Ed ----- Original Message -----=20 From: John Downing=20 To: Rotary motors in aircraft=20 Sent: Thursday, March 01, 2007 9:39 AM Subject: [FlyRotary] diffusers Ed, If I add the extension, indicated with cardboard w/lines, I = have the original 22 1/4 sq. in's. If I block off the cowl openings to = match the diffuser, I will have 18 7/8 sq. inches. The neck at the = smallest point is approximately 15 sq. inches as close as I can = determine by my barn door math. Which is the better way to go, opening = wise, the larger or the smaller opening. If these numbers are in the = ball park, I'll lay up the glass. Thankyou JohnD -------------------------------------------------------------------------= --- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0037_01C75C02.4ABFC400 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
John, I agree,
 
the way your cowl looks, it does not = make sense (to=20 me....) to reduce the intake size the way you indicate.
If you were to reduce the intake from = the outside=20 in, including narrowing the cowl, then discuss the size.
As is, might as well use it, the = frontal area is=20 the same, whether it is open or closed off.
 
Thomas
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Thursday, March 01, 2007 = 9:53=20 AM
Subject: [FlyRotary] Re: = diffusers

John, I would go with the 22 1/4 sq = inches.  For=20 these reasons:
 
1.  Your engine may produce more power = than the one=20 I run with - requiring more heat rejection.
2.  It is easier to neck down the opening = (than=20 widen it)  if it turns out you have more than what is necessary - = or do=20 nothing
3.  My cowl exit area is probably a bit = larger than=20 most which may produce less back pressure enabling smaller opening to = flow=20 more air.
 
Ball up your fist and see if you can stick it = through=20 the narrowest opening - it should just almost go (that is if you have = the same=20 size hands I do {:>))  How's that for a standard of=20 measure?
 
 
Ed
----- Original Message -----
From:=20 John=20 Downing
To: Rotary motors in = aircraft=20
Sent: Thursday, March 01, = 2007 9:39=20 AM
Subject: [FlyRotary] = diffusers

Ed,  If I add the extension, = indicated=20 with cardboard w/lines, I have the original 22 1/4 sq. in's.  = If I=20 block off the cowl openings to match the diffuser, I will have 18 = 7/8 sq.=20 inches.  The neck at the smallest point is approximately 15 sq. = inches=20 as close as I can determine by my barn door math.  Which is the = better=20 way to go, opening wise, the larger or the smaller opening.  If = these=20 numbers are in the ball park, I'll lay up the glass.  = Thankyou =20 JohnD

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Homepage:  http://www.flyrotary.com/
Archive = and=20 UnSub:  =20 = http://mail.lancaironline.net/lists/flyrotary/
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