Return-Path: Received: from fed1rmmtao09.cox.net ([68.230.241.30] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 762838 for flyrotary@lancaironline.net; Mon, 28 Feb 2005 12:14:21 -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 <20050228171335.CKIT19936.fed1rmmtao09.cox.net@BigAl> for ; Mon, 28 Feb 2005 12:13:35 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: Pumping power Date: Mon, 28 Feb 2005 09:13:45 -0800 Message-ID: <000001c51db8$dc4fea60$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C51D75.CE2CAA60" 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_01C51D75.CE2CAA60 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable 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? =20 Jim; I don't know that Paul was off, I was just agreeing with Dale that he = may have been. I found in my notes that the estimated (stock) pump power at = 6000 rpm was about 2.5 - 3 hp, so the 10 seems too high; but I can not find = any data in my file to back it up. Paul did set up a test loop and do measurements - I don't have the results. Bill Jepson provided flow and pressure drop data which could be translated to power. =20 If it is 3 hp, one might expect similar power required for EWP pump = drive to produce the same flow rate (power to generate the current not = included); however I expect the EWP pump efficiency to be higher because it seems apparent looking at the stock pump impeller that not much effort was = made for high efficiency. Until someone does consistent flow rate - power = data for both pumps, we don't know. Did PL ever do that? =20 On the dyno test, I measured 48 gpm at 6000 rpm for the pump on my 20B, (which is interesting that it is close to Jack's data point of 3 hp = pumping 52 gpm) but the external loop was likely lower pressure drop than rads = on my airplane. =20 Al >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0001_01C51D75.CE2CAA60 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

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?

Jim;

I don’t =
know that Paul was off, I was just agreeing with Dale that he may have =
been. I found in my notes that the estimated (stock) pump power at 6000 =
rpm was about 2.5 - 3 hp, so the 10 seems too high; but I can not find =
any data in my file to back it up. Paul did set up a test loop and do =
measurements – I don’t have the results. Bill Jepson =
provided flow and pressure drop data which could be translated to =
power.

 If it is 3 =
hp, one might expect similar power required for EWP pump drive to =
produce the same flow rate (power to generate the current not included); =
however I expect the EWP pump efficiency to be higher because it seems =
apparent looking at the stock pump impeller that not much effort was =
made for high efficiency.  Until someone does consistent flow rate =
– power data for both pumps, we don’t know.  Did PL =
ever do that?

On the dyno =
test, I measured 48 gpm at 6000 rpm for the pump on my 20B, (which is =
interesting that it is close to Jack’s data point of 3 hp pumping =
52 gpm)  but the external loop was likely lower pressure drop than =
rads on my airplane.

Al

>>  Homepage:  http://www.flyrotary.com/

>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html

------=_NextPart_000_0001_01C51D75.CE2CAA60--