Return-Path: Received: from fed1rmmtao03.cox.net ([68.230.241.36] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 769636 for flyrotary@lancaironline.net; Fri, 04 Mar 2005 01:51:37 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.36; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao03.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with ESMTP id <20050304065047.JEAV1282.fed1rmmtao03.cox.net@BigAl> for ; Fri, 4 Mar 2005 01:50:47 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: EWP Test Resulsts Date: Thu, 3 Mar 2005 22:50:49 -0800 Message-ID: <000001c52086$801d2f70$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C52043.71F9EF70" 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_01C52043.71F9EF70 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable What was the problem again that you're trying to solve by using the EWP? =20 If you are trying to save a very small amount of power at the expense of flow rate, then let's be looking at a smaller mechanically driven pump. Then you at least aren't spending 25% of the total energy needed = converting mechanical energy to electrical back to mechanical. =20 But why take a significant cut in flow rate to save 1 hp? High flow = rate is good. It gives you better heat rejection system design, lower dT across = the engine, better internal circulation for more uniform temps. And why = risk a 50-70 degree dT from the hot side to cold side of the engine. That's = not a good thing. Not to mention the risk of internal hot spots from low = flow; in places like around the spark plugs. Have you seen the micro-cracks that = can occur in the housings from over temp there? Lower flow will work, but = is it a good thing? And I suppose there may be some reason, like = configuration, for using a EWP, so get the big one and design to provide it the current = it needs. =20 And it is further confusing to me that with the lower flow rate with = water; we are now talking about using a much higher viscosity Evans coolant = with an EWP? =20 Al (it must be past my bedtime; I'm beginning to sound emotional) ------=_NextPart_000_0001_01C52043.71F9EF70 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

What was the problem again that you’re trying to solve by using the = EWP?

 

If you are trying to save a very = small amount of power at the expense of flow rate, then let’s be looking = at a smaller mechanically driven pump.  Then you at least aren’t = spending 25% of the total energy needed converting mechanical energy to = electrical back to mechanical.

 

But why take a significant cut in = flow rate to save 1 hp?  High flow rate is good.  It gives you = better heat rejection system design, lower dT across the engine, better internal circulation for more uniform temps.  And why risk a 50-70 degree dT = from the hot side to cold side of the engine.  That’s not a good thing.  Not to mention the risk of internal hot spots from low = flow; in places like around the spark plugs.  Have you seen the micro-cracks = that can occur in the housings from over temp there?  Lower flow will = work, but is it a good thing?  And I suppose there may be some reason, like configuration, for using a EWP, so get the big one and design to provide = it the current it needs.

 

And it is further confusing to me = that with the lower flow rate with water; we are now talking about using a = much higher viscosity Evans coolant with an EWP?

 

Al (it must be past my bedtime; = I’m beginning to sound emotional)

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