X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta09-srv.alltel.net ([166.102.165.170] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1043224 for flyrotary@lancaironline.net; Wed, 22 Mar 2006 20:31:19 -0500 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.170; envelope-from=montyr2157@alltel.net Received: from Thorstwin ([67.141.69.203]) by ispmxmta09-srv.alltel.net with SMTP id <20060323013033.KXYS16513.ispmxmta09-srv.alltel.net@Thorstwin> for ; Wed, 22 Mar 2006 19:30:33 -0600 Message-ID: <003f01c64e19$6821eac0$01fea8c0@Thorstwin> From: "M Roberts" To: Subject: pitot inlet Date: Wed, 22 Mar 2006 19:30:45 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003C_01C64DE7.1D63C620" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_003C_01C64DE7.1D63C620 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Monty, When you suggested using a pitot style air intake for the cooling, what = exactly did you mean by 'pitot'. I envision it to be a tubular structure = that extends forward of the wing's leading edge, but would the extension = be a slight bump or a lance worthy of slaying dragons? As it stands, I = have about 32" from the leading edge for a duct to feed a 4" thick, = 13.5"x9" radiator. (I'm still trying to source a radiator without going = the custom build route.) I don't need any more length to get a fully = developed K&W streamlined duct, but if I need to extend the opening out = significantly from the leading edge it will need to be incorporated into = the design. Ernest, I was a little unclear. I meant a standard leading edge inlet. Nothing = too fancy. If you look at the leading edge of the Corsair you will see = the inlets for the oil cooler. That is what I had in mind. I would keep = the ducts as short as possible while still maintaining reasonable = efficiency. You don't need a really long diffuser to get good = performance. That extra length only adds a small amount of pressure = recovery, but it adds a lot of weight and internal drag. Pressure = recovery is nice, but it isn't everything. You only need enough pressure = differential to make the air go through the radiator. Remember the idea = of making a "jet" out of this thing is a loosing proposition. People = like to talk about the air "squirting" out through the exit. That is = pretty unlikely. More likely is reducing the internal flow and lowering = momentum and internal viscous drag. Twist the big knob first, leave the = fine adjustment for later :-). I would locate the inlets in the outer portion of the prop arc. There is = much more velocity there for ground cooling. You have a unique situation = where that is possible.=20 Monty ------=_NextPart_000_003C_01C64DE7.1D63C620 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Monty,

When=20 you suggested using a pitot style air intake for the cooling, what = exactly did=20 you mean by 'pitot'. I envision it to be a tubular structure that = extends=20 forward of the wing's leading edge, but would the extension be a slight = bump or=20 a lance worthy of slaying dragons? As it stands, I have about 32" from = the=20 leading edge for a duct to feed a 4" thick, 13.5"x9" radiator. (I'm = still trying=20 to source a radiator without going the custom build route.) I don't need = any=20 more length to get a fully developed K&W streamlined duct, but if I = need to=20 extend the opening out significantly from the leading edge it will need = to be=20 incorporated into the design.

Ernest,
 
I was a little unclear. I meant a = standard leading=20 edge inlet. Nothing too fancy. If you look at the leading edge of the = Corsair=20 you will see the inlets for the oil cooler. That is what I had in = mind. I=20 would keep the ducts as short as possible while still maintaining = reasonable=20 efficiency. You don't need a really long diffuser to get good = performance. That=20 extra length only adds a small amount of pressure recovery, but it adds = a lot of=20 weight and internal drag. Pressure recovery is nice, but it isn't = everything.=20 You only need enough pressure differential to make the air go = through the=20 radiator. Remember the idea of making a "jet" out of this thing is a = loosing=20 proposition. People like to talk about the air "squirting" out through = the exit.=20 That is pretty unlikely. More likely is reducing the internal flow and = lowering=20 momentum and internal viscous drag. Twist the big knob first, = leave the=20 fine adjustment for later :-).
 
I would locate the inlets in the outer = portion of=20 the prop arc. There is much more velocity there for ground cooling. You = have a=20 unique situation where that is possible.
 
 
Monty
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