Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2644012 for flyrotary@lancaironline.net; Mon, 20 Oct 2003 16:11:59 -0400 Received: from ms-mss-03-ce0-1 ([10.10.1.39]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with ESMTP id h9KKBvR8020964 for ; Mon, 20 Oct 2003 16:11:57 -0400 (EDT) Received: from southeast.rr.com (localhost [127.0.0.1]) by ms-mss-03.southeast.rr.com (iPlanet Messaging Server 5.2 HotFix 1.12 (built Feb 13 2003)) with ESMTP id <0HN200CUTO3XWR@ms-mss-03.southeast.rr.com> for flyrotary@lancaironline.net; Mon, 20 Oct 2003 16:11:57 -0400 (EDT) Received: from [10.10.1.22] by ms-mss-03.southeast.rr.com (mshttpd); Mon, 20 Oct 2003 16:11:57 -0400 Date: Mon, 20 Oct 2003 16:11:57 -0400 From: echristley@nc.rr.com Subject: Re: [FlyRotary] Re: Water pumps Somebody STOP me! To: Rotary motors in aircraft Reply-to: echristley@nc.rr.com Message-id: <42821e4296ad.4296ad42821e@southeast.rr.com> MIME-version: 1.0 X-Mailer: iPlanet Messenger Express 5.2 HotFix 1.12 (built Feb 13 2003) Content-type: multipart/mixed; boundary="Boundary_(ID_vHReiuNgPR968OyTJnt3cQ)" Content-language: en X-Accept-Language: en Priority: normal X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. --Boundary_(ID_vHReiuNgPR968OyTJnt3cQ) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-disposition: inline Forgive me for being slow here, but there are quite a few more lines on this graph than I'm used to. Does this graph say that as the head pressure rises to 100ft, it raises the water temp by about 40 degree,and yet uses nearly 10HP to do it? Content-Type: multipart/alternative; boundary="----=_NextPart_001_0A85_01C39682.B1BBDDE0" ------=_NextPart_001_0A85_01C39682.B1BBDDE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Here is a .GIF that illustrates both our points. At zero flow, the pump = shaft horsepower is less than at rated flow, but all the energy is going = into heating the water. I believe that the reason Davies Craig claims that they save a lot of = horsepower, is because at high rpm, the pump is not running at its high = efficiency point. It is clear from the successful EWP tests of Todd, = that the actual energy required to pump the water is small. So if DC is = correct, then they are using the high rpm point for the "horsepower = saved". Bill Schertz Tracy Wrote: All true. But my point was that there is still *less* shaft HP = required to turn the pump when the thermostat restricts the flow through = the pump and we are not wasting engine HP by having a restriction in the = circuit as is occasionally claimed. True, the pump is operating in a = less efficient part of its operating curve, but do we really care? Tracy ------=_NextPart_001_0A85_01C39682.B1BBDDE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Here is a .GIF that illustrates both = our points. At=20 zero flow, the pump shaft horsepower is less than at rated flow, but all = the=20 energy is going into heating the water.

I believe that the reason Davies Craig = claims that=20 they save a lot of horsepower, is because at high rpm, the pump is not = running=20 at its high efficiency point. It is clear from the successful EWP tests = of Todd,=20 that the actual energy required to pump the water is small. So if DC is = correct,=20 then they are using the high rpm point for the "horsepower = saved".

Bill Schertz

Tracy=20 Wrote:

All true. But my point was = that there is=20 still *less* shaft HP required to turn the pump when the thermostat=20 restricts the flow through the pump and we are not wasting engine HP = by=20 having a restriction in the circuit as is occasionally = claimed. True,=20 the pump is operating in a less efficient part of its operating = curve, but=20 do we really care?

Tracy

= ------=_NextPart_001_0A85_01C39682.B1BBDDE0-- --Boundary_(ID_vHReiuNgPR968OyTJnt3cQ) Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7BIT Content-disposition: inline >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html --Boundary_(ID_vHReiuNgPR968OyTJnt3cQ)--