Return-Path: <13brv3@bellsouth.net> Received: from imf18aec.mail.bellsouth.net ([205.152.59.66] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 768857 for flyrotary@lancaironline.net; Thu, 03 Mar 2005 14:26:00 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.66; envelope-from=13brv3@bellsouth.net Received: from rd ([65.6.194.9]) by imf18aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050303192516.SVZB2073.imf18aec.mail.bellsouth.net@rd> for ; Thu, 3 Mar 2005 14:25:16 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: EWP Test Results/DRAG Date: Thu, 3 Mar 2005 13:26:10 -0600 Message-ID: <009301c52026$dafeb9a0$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0094_01C51FF4.906449A0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0094_01C51FF4.906449A0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable We all agree that the EWP flows less than the standard pump by alot = (maybe only half to 1/3th as much?).=20 =20 For the EWP's we're trying, I agree, but they do make larger EWP's. At = the same time, I think most of us can agree that the stock pump flows too = much for what we're doing. Why would anyone slow it down by changing pulleys = if it really needed to be flowing that much. =20 =20 But if you have less flow then the radiator MUST be larger for the = engine to obtain equal cooling.=20 =20 Technically, I agreed, but the difference in size might be = insignificant, depending on how much you change the flow. =20 =20 This equates to more drag. Now does the EWP save more energy than = the ~3HP the mechanical pump uses even when the extra cooling drag in = factored? In other words, does the EWP save 3HP worth of cooling drag? I suspect = that the mechanical pump is more effecient but can't prove it. Bill, Al, Ed = and some of the engineers can probably give us a good idea though (and = have). No numbers here, I'm just trying to piont out the real issue =20 =20 Following this same line of reasoning, you can install an eccentric = shaft pulley the size of a steering wheel, and then replace your radiator with = an oil cooler from a Lycoming. You'd be almost drag free :-) =20 What I would like to see, is a dyno run, where everything is held = constant with the exception of the water (better make it Evans) flow rate. I'd = be willing to bet that the relationship between equilibrium temp, and flow = rate will not be a straight line. I would expect that it's more of an exponential shape. My guess is that the stock pump flow rate is located = far out on this curve, such that a 10 gpm change won't make hardly any diff = in temp. =20 =20 OK all you engineers, really let me have it now :-) =20 Cheers, Rusty (I'll abuse Ernest later) =20 =20 ------=_NextPart_000_0094_01C51FF4.906449A0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
We all agree that the EWP flows less than the standard pump by alot = (maybe=20 only half to 1/3th as much?). 
 
For the EWP's=20 we're trying, I agree, but they do make larger EWP's.   At the = same=20 time, I think most of us can agree that the stock pump flows too much = for what=20 we're doing.  Why would anyone slow it down by changing pulleys if = it=20 really needed to be flowing that much. 
 
But if you have less flow then the radiator MUST be larger for the = engine=20 to obtain equal cooling. 
 
Technically,=20 I agreed, but the difference in size might be insignificant, depending = on how=20 much you change the flow. 
 
   This equates = to more=20 drag.  Now does the EWP save more energy than the ~3HP the = mechanical=20 pump uses even when the extra cooling drag in factored?  In other = words,=20 does the EWP save 3HP worth of cooling drag?  I suspect that the = mechanical=20 pump is more effecient but can't prove it.  Bill, Al, Ed and some = of the=20 engineers can probably give us a good idea though (and have).  No = numbers=20 here, I'm just trying to piont out the real issue  
 
Following=20 this same line of reasoning, you can install an eccentric shaft = pulley the=20 size of a steering wheel, and then replace your radiator with an oil = cooler from=20 a Lycoming.  You'd be almost drag free  = :-)
 
What I would=20 like to see, is a dyno run, where everything is held constant with the = exception=20 of the water (better make it Evans) flow rate.  I'd be willing = to bet=20 that the relationship between equilibrium temp, and flow rate will not = be a=20 straight line.  I would expect that it's more of an exponential=20 shape.  My guess is that the stock pump flow rate is located far = out on=20 this curve, such that a 10 gpm change won't make hardly any diff in = temp. =20
 
OK all you=20 engineers, really let me have it now :-)
 
Cheers,
Rusty (I'll=20 abuse Ernest later)
 
 
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