Return-Path: Received: from mail.theofficenet.com ([65.166.240.5] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with SMTP id 761892 for flyrotary@lancaironline.net; Sun, 27 Feb 2005 16:02:07 -0500 Received-SPF: none receiver=logan.com; client-ip=65.166.240.5; envelope-from=jackoford@theofficenet.com Received: (qmail 26433 invoked from network); 27 Feb 2005 20:31:38 -0000 Received: from dpc691941229.direcpc.com (HELO jack) (69.19.41.229) by mail.theofficenet.com with SMTP; 27 Feb 2005 20:31:38 -0000 Message-ID: <00d901c51d0f$61905110$0200a8c0@jack> From: "Jack Ford" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: [FlyRotary]Belt rumnations; soliciting Opinions of racers please.... Date: Sun, 27 Feb 2005 13:00:24 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00D4_01C51CCC.4D7FBB90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 This is a multi-part message in MIME format. ------=_NextPart_000_00D4_01C51CCC.4D7FBB90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I had a 3/4 horsepower pump that moved 13 gallons per minute of water = out of a 100' deep well, 40' head minimum. It was a lot faster than that until I drew the well down to it's = production rate, but I only measured the production rate. Extrapolating from that, 3 horsepower will move 52+ GPM. Different kind = of pump, different environment. Data point. Jack Ford ----- Original Message -----=20 From: Jim Sower=20 To: Rotary motors in aircraft=20 Sent: Sunday, February 27, 2005 12:36 PM Subject: [FlyRotary] Re: [FlyRotary]Belt rumnations; soliciting = Opinions of racers please.... Al, I made a quick analysis from facts obtained elsewhere. I surmised = that PL was right about the 10 hp at high rpm because I've heard that = number from so many sources over the years. How considerably off do you = think PL was and why? I seem to recall that PL's case against EWP was = that since water pumps require 10 hp, you'd need a 10 hp motor to drive = the EWP. As for the 0.1 hp of EWP, I'm pretty sure someone on this = list that's using one reported that his EWP draws about 5 amps in = operation. Starting from there, the math is pretty straightforward. Anyway, I'm a believer until I hear something really compelling ... = Jim S. Al Gietzen wrote:=20 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 >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html =20 >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_00D4_01C51CCC.4D7FBB90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I had a 3/4 horsepower pump that moved = 13 gallons=20 per minute of water out of a 100' deep well, 40' head = minimum.
It was a lot faster than that until I = drew the well=20 down to it's production rate, but I only measured the production=20 rate.
 
Extrapolating from that, 3 horsepower = will move 52+=20 GPM. Different kind of pump, different environment.
 
Data point.
 
Jack Ford
----- Original Message -----
From:=20 Jim=20 Sower
Sent: Sunday, February 27, 2005 = 12:36=20 PM
Subject: [FlyRotary] Re: = [FlyRotary]Belt=20 rumnations; soliciting Opinions of racers please....

Al,
I made a quick analysis from facts obtained=20 elsewhere.  I surmised that PL was right about the 10 hp at high = rpm=20 because I've heard that number from so many sources over the = years.  How=20 considerably off do you think PL was and why?  I seem to recall = that PL's=20 case against EWP was that since water pumps require 10 hp, you'd need = a 10 hp=20 motor to drive the EWP.   As for the 0.1 hp of EWP, I'm pretty = sure=20 someone on this list that's using one reported that his EWP draws = about 5 amps=20 in operation.  Starting from there, the math is pretty=20 straightforward.
Anyway, I'm a believer until I hear something = really=20 compelling ... Jim S.

Al Gietzen wrote:=20 
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 =91performance =
improvement=92 you may see with EWP vs belt driven pump comes from lower =
flow rate.  
Al
 
  
 
  =

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