Return-Path: Received: from fed1rmmtao06.cox.net ([68.230.241.33] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 761298 for flyrotary@lancaironline.net; Sun, 27 Feb 2005 01:41:22 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.33; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao06.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with ESMTP id <20050227064032.MPDJ1497.fed1rmmtao06.cox.net@BigAl> for ; Sun, 27 Feb 2005 01:40:32 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: [FlyRotary]Belt rumnations; soliciting Opinions of racers please.... Date: Sat, 26 Feb 2005 22:40:39 -0800 Message-ID: <000001c51c97$4062bfa0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C51C54.323F7FA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C51C54.323F7FA0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable The case for EWP for example is performance. PL insisted that an EDWP absorbs over 10 hp at 6000 rpm. He is probably damned close. He then = made the unfortunate leap that therefore an EWP must absorb the same power. = Not true. EWP conservatively absorbs 14V x 5 A =3D 70 W =3D~ 0.1 hp. He = was off by about two orders of magnitude or about 9.9 hp. Don't know about you = but I can always use an extra 9.9 hp. =20 PL may have been considerably off; but at .1hp with the EWP you will be getting only a fraction of the flow of the belt driven pump; even if it = were 100% efficient. Keep in mind that converting power into electricity is about 85% efficient, as is converting electricity back into power. 0.85 = x 0.85 =3D 0.72; so you have lost 28% of the power in the process. = Pumping coolant against even a small pressure head takes power. Any = 'performance improvement' you may see with EWP vs belt driven pump comes from lower = flow rate. =20 Al =20 =20 =20 =20 >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0001_01C51C54.323F7FA0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

The =
case for EWP for example is performance.  PL insisted that an EDWP =
absorbs over 10 hp at 6000 rpm.  He is probably damned close.  =
He then made the unfortunate leap that therefore an EWP must absorb the =
same power.  Not true.  EWP conservatively absorbs 14V x 5 A =
=3D 70 W =3D~ 0.1 hp.  He was off by about two orders of magnitude or about =
9.9 hp.  Don't know about you  but I can always use an extra =
9.9 hp.

PL may have =
been considerably off; but at .1hp with the EWP you will be getting only =
a fraction of the flow of the belt driven pump; even if it were 100% =
efficient.  Keep in mind that converting power into electricity is =
about 85% efficient, as is converting electricity back into power. 0.85 =
x 0.85 =3D 0.72; so you have lost 28% of the power in the process. =
 Pumping coolant against even a small pressure head takes =
power.  Any ‘performance improvement’ you may see with =
EWP vs belt driven pump comes from lower flow rate.  =

Al

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