Return-Path: Received: from fed1mtao02.cox.net ([68.6.19.243] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2649572 for flyrotary@lancaironline.net; Fri, 24 Oct 2003 12:46:12 -0400 Received: from BigAl ([68.107.116.221]) by fed1mtao02.cox.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20031024164605.HCTG27579.fed1mtao02.cox.net@BigAl> for ; Fri, 24 Oct 2003 12:46:05 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] radiator tube sizing Date: Fri, 24 Oct 2003 09:46:13 -0700 Message-ID: <000001c39a4e$564a43a0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C39A13.A9EB6BA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4024 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C39A13.A9EB6BA0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Kelly, I ran some numbers through the spreadsheet I created. This assumes that we need to maintain a 20cfm flowrate. I got the data and equations off the net. Do a google search with "flow resistance weldbend". The first link takes you to a page that explains 'bend equivalence' and the next page (link at bottom) explains how to calculate flow rates and Questions for the list. How does the cooling performance drop as the flowrate goes down? Is 20cfm the very minimum flow necessary to provide adequate cooling? Maybe better check your flow rate units; gpm vs cfm. 20 cfm is way too high. For a 2-rotor you'd probably need a max of around 25 gpm, which is about 3.5 cfm. Al ------=_NextPart_000_0001_01C39A13.A9EB6BA0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Kelly,

I ran some numbers through the spreadsheet I created. This assumes = that we need to maintain a 20cfm flowrate. I got the data and equations = off the net. Do a google search with "flow resistance weldbend". = The first link takes you to a page that explains 'bend equivalence' and the = next page (link at bottom) explains how to calculate flow rates and Questions = for the list.

How does the cooling performance drop as the flowrate goes = down?

Is 20cfm the very minimum flow necessary to provide adequate = cooling?

Maybe better check your flow rate units; gpm vs = cfm. 20 cfm is way too high. For a 2-rotor you’d probably need a max = of around 25 gpm, which is about 3.5 cfm.

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