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Return-Path: <13brv3@bellsouth.net> Received: from imf25aec.mail.bellsouth.net ([205.152.59.73] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2645284 for flyrotary@lancaironline.net; Tue, 21 Oct 2003 11:52:29 -0400 Received: from rad ([65.80.160.144]) by imf25aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20031021155218.ZBZA1822.imf25aec.mail.bellsouth.net@rad> for ; Tue, 21 Oct 2003 11:52:18 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: temps behind radiator? Date: Tue, 21 Oct 2003 10:52:21 -0500 Message-ID: <00a901c397eb$5030f3c0$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00AA_01C397C1.675AEBC0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_00AA_01C397C1.675AEBC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable This, of course, assumes that you have the same incoming air temp to = both. Putting the oil cooler behind the radiator throws a big wrench into optimizing the cooling systems; and is a bad idea from the git-go. Heat rejected is pretty much proportional to the temp difference between the = air and the coolant/or oil. But if that=92s your only configuration option, = and the air temp increase through the rad is, say, 35F; and you want to = climb out on a 90F day, you can expect to need an oil cooler core volume of roughly 1 =BD times normal; or about =BE the size of the rad. =20 This is rough estimating and assumes equal effectiveness of rad and = cooler; but you get the idea. =20 Al=20 =20 Thanks for the info Al. I spent some time considering moving the oil = cooler to the right cheek, but that causes me more problems than it solves. = Since the oil cooler will likely be putting out less heat than the radiator, = it would seem to make better sense to have the oil cooler in front of the radiator, rather than the way I have it now. That's easy enough to do = in the rev 2 configuration, and it's about test #3 on the list now. I can = do it quick and ugly with my current hoses, though I'll receive more abuse = from the natives since it will require that I route the hoses briefly outside = the cowl to get around the side of the radiator. Say what you want about my BUC, but I'm actually glad that I didn't try to make a final cowl in the beginning. I've been able to do experiments with BUC that I would have never done with a "pretty" cowl. =20 Cheers, Rusty =20 =20 =20 ------=_NextPart_000_00AA_01C397C1.675AEBC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message

This, of = course,=20 assumes that you have the same incoming air temp to both. Putting = the oil=20 cooler behind the radiator throws a big wrench into optimizing the = cooling=20 systems; and is a bad idea from the git-go. Heat rejected is = pretty much=20 proportional to the temp difference between the air and the coolant/or = oil. But=20 if that’s your only configuration option, and the air temp = increase through the=20 rad is, say, 35F; and you want to climb out on a 90F day, you can expect = to need=20 an oil cooler core volume of roughly 1 =BD times normal; or about =BE = the size of=20 the rad.

This is = rough=20 estimating and assumes equal effectiveness of rad and cooler; but you = get the=20 idea.

Al

Thanks for the=20 info Al. I spent some time considering moving the oil cooler to = the right=20 cheek, but that causes me more problems than it solves. Since = the oil=20 cooler will likely be putting out less heat than the radiator, it = would=20 seem to make better sense to have the oil cooler in front of the = radiator,=20 rather than the way I have it now. That's easy enough to = do in=20 the rev 2 configuration, and it's about test #3 on the list = now. I=20 can do it quick and ugly with my current hoses, though I'll receive more = abuse=20 from the natives since it will require that I route the hoses = briefly=20 outside the cowl to get around the side of the = radiator. =20 Say what you want about my BUC, but I'm actually glad = that I=20 didn't try to make a final cowl in the = beginning. I've been able to do experiments = with BUC that I=20 would have never done with a "pretty" = cowl.

Cheers,

Rusty =20

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