Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2926975 for flyrotary@lancaironline.net; Sat, 10 Jan 2004 18:26:32 -0500 Received: from edward (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i0ANQUYr005471 for ; Sat, 10 Jan 2004 18:26:30 -0500 (EST) Message-ID: <001001c3d7d1$b8aa4890$2402a8c0@edward> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Radiator ducting Date: Sat, 10 Jan 2004 18:30:23 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01C3D7A7.CF9FC310" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C3D7A7.CF9FC310 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Don't know where you would find that type tubing. However, recall those = yellow/orange caution traffic cones? {:>) You might have to resort to = fiberglass as I did. Ed ] Re: Radiator ducting Thanks Ed. I guess it might be a good idea to go around with a measuring tape and = look at planes with Sam James, Lu Presti and other round inlets cowls. = But I guess 4.5 to 5" diameter is reasonable. I just measured my right radiator location. As you know, it is slanted = fore/aft. One side (closest to prop hub) is 6" from prop edge, and the = outboard edge is 13.5" from the prop edge. Coming from a 5" diameter = inlet, what should the ducting look like? Bell or trumpet shaped? Or = just direct lines from each point on the radiator circumference to = nearest point on the inlet circle? Where do I find some 5" diameter tubing that will stretch to 12" = diameter (or 9" x 10" square)? Finn Ed Anderson wrote: Finn, I would not go below about 18 square inches initially. I did reduce = one of my duct openings to around 9-10 square inches, but left the other one = at 24 square inches. Cooling is still fine (increased coolant temp by 5F), = but I suspect the 24 Square inche one is carrying more of the load. K&W indicates that if your inlet opening is below a certain critical ratio = then the losses go way up. Using the 95 square inches of the cores I = calculated that 18 square inches was a good minimum. If you duct shape and outlet = are close to optimum you could go smaller, but then things have got to be = just right. I know that 24 square inches per core works great, and my total coolant inlet are is now at 33 square inches and still cooled on 90F = day. I would pay particular attention to the lower lip of your inlet making = certain it has a sort of airfoil curve to it so that air will find an easy path = when the nose is up relative to the airstream (like during your climb). Don't have a clue as to whether the "round" inlets are better, some = folks believe so. Van sort of poop pooed the idea at one dinner. Ed Anderson Homepage: http://www.flyrotary.com/ Archive: http://lancaironline.net/lists/flyrotary/List.html =20 ------=_NextPart_000_000D_01C3D7A7.CF9FC310 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Don't know where you would find that = type=20 tubing.  However, recall those yellow/orange caution traffic cones? = {:>)  You might have to resort to fiberglass as I = did.
 
Ed
 ] Re: Radiator ducting

Thanks Ed.

I guess it might be a good idea to go = around=20 with a measuring tape and look at planes with Sam James, Lu Presti and = other=20 round inlets cowls. But I guess 4.5 to 5" diameter is = reasonable.

I=20 just measured my right radiator location. As you know, it is slanted = fore/aft.=20 One side (closest to prop hub) is 6" from prop edge, and the outboard = edge is=20 13.5" from the prop edge. Coming from a 5" diameter inlet, what should = the=20 ducting look like? Bell or trumpet shaped? Or just direct lines from = each=20 point on the radiator circumference to nearest point on the inlet=20 circle?

Where do I find some 5" diameter tubing that will = stretch to=20 12" diameter (or 9" x 10" square)?

Finn

Ed Anderson = wrote:
Finn,

    I would not go below about 18 square inches initially.  I did reduce =
one
of my duct openings to around 9-10 square inches, but left the other one =
at
24 square inches.  Cooling is still fine (increased coolant temp by 5F), =
but
I suspect the 24 Square inche one is carrying more of the load.   =
K&W
indicates that if your inlet opening is below a certain critical ratio =
then
the losses go way up.  Using the 95 square inches of the cores I =
calculated
that 18 square inches was a good minimum.  If you duct shape and outlet =
are
close to optimum you could go smaller, but then things have got to be =
just
right.  I know that 24 square inches per core works great, and my total
coolant inlet are is now at 33 square inches and still cooled on 90F =
day.  I
would pay particular attention to the lower lip of your inlet making =
certain
it has a sort of airfoil curve to it so that air will find an easy path =
when
the nose is up relative to the airstream (like during your climb).

Don't have a clue as to whether the "round" inlets are better, some =
folks
believe so.  Van sort of poop pooed the idea at one dinner.


Ed Anderson


  
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