Return-Path: Received: from fed1rmmtao09.cox.net ([68.230.241.30] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 763846 for flyrotary@lancaironline.net; Mon, 28 Feb 2005 21:30:54 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.30; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao09.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with ESMTP id <20050301023009.MRBE19936.fed1rmmtao09.cox.net@BigAl> for ; Mon, 28 Feb 2005 21:30:09 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Pumping power Date: Mon, 28 Feb 2005 18:30:19 -0800 Message-ID: <000001c51e06$9cf50eb0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C51DC3.8ED1CEB0" 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_01C51DC3.8ED1CEB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Al, What PL said and did is hearsay to me, as is all the other ~10 hp=20 anecdotes I've always heard. Your dyno data has to be a lot more=20 credible at least as far as it goes. Was the 48 gpm that was required=20 free flowing (no thermostat) from a cold reservoir through the engine=20 and back? Or was it closer to simulating actual conditions - hot water=20 in, hotter water out, operating at pretty much the temperatures you'd=20 expect in flight? =20 The 48 gpm @ 6000 was without thermostat installed, with a recirculating loop through a radiator much like actual conditions in the airplane; = except that the lines and the rad were larger. With the thermostat installed, = the flow rate was 37 gpm; a significant drop due to the additional flow resistance. The flow curves are shown on the dyno report - http://members.cox.net/alg3/Dynamometer%20test%20report.htm. The data = points on the chart that are not connected are for the case of thermostat installed. =20 I am intuiting / speculating (key words here) that a pump that works=20 great at idle or in heavy traffic is going to be thrashing around=20 wasting a LOT of power at 6000 (or 7000) rpm through cavitation or=20 whatever. =20 I don't think there is any evidence for that conclusion. Higher rpm = simply translates to higher flow. I'm sure there is a point where cavitation = will occur, but the flow behavior was fairly linear with rpm all the way up = to 7000 rpm. =20 Al ------=_NextPart_000_0001_01C51DC3.8ED1CEB0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Al,

What PL said and did is hearsay to me, as is all the other ~10 hp =

anecdotes I've always heard. Your dyno data has to be a lot more =

credible at least as far as it goes. Was the 48 gpm that was required =

free flowing (no thermostat) from a cold reservoir through the engine =

and back? Or was it closer to simulating actual conditions - hot water =

in, hotter water out, operating at pretty much the temperatures you'd =

expect in flight?

 

The 48 gpm @ = 6000 was without thermostat installed, with a recirculating loop through a = radiator much like actual conditions in the airplane; except that the lines and the = rad were larger.  With the thermostat installed, the flow rate was 37 gpm; a significant drop due to the additional flow resistance.  The flow = curves are shown on the dyno report - http= ://members.cox.net/alg3/Dynamometer%20test%20report.htm= . The data points on the chart that are not connected are for the case of = thermostat installed.

 

I am intuiting / speculating (key words here) that a pump that works =

great at idle or in heavy traffic is going to be thrashing around =

wasting a LOT of power at 6000 (or 7000) rpm through cavitation or =

whatever.

 

I don’t = think there is any evidence for that conclusion. Higher rpm simply translates = to higher flow.  I’m sure there is a point where cavitation will = occur, but the flow behavior was fairly linear with rpm all the way up to 7000 = rpm.

 <= /font>

Al

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