X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 970490 for flyrotary@lancaironline.net; Sat, 04 Feb 2006 20:57:24 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-04-eri0.southeast.rr.com (8.13.4/8.13.4) with SMTP id k151ucGX008819 for ; Sat, 4 Feb 2006 20:56:40 -0500 (EST) Message-ID: <000b01c629f7$6dc8e0a0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: NPG Coolant Temperature vs 50/50 Date: Sat, 4 Feb 2006 20:56:49 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01C629CD.848549C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C629CD.848549C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Al, Appreciate your (anybody else welcome also) views on one other thing = that is still bothering me about the use of NPG. =20 Given that NPG+ has a specific heat of 0.66 at 212F or 20% less than = the 0.82 for the 50/50 mixture and given that NPG+ is approx 7% more = dense than the 50/50 - then that for the same flowrate for both it would = seem that NPG still has a 13% lesser overall capacity for heat transfer = (at the same temps 212F and flow rates). Also assume that the engine is produce the same heat load (Q),lets take = alook at what temperature we might see with NPG+ compared to the 50/50 = solution. We have from the oldie but goody Q =3D c*M*DeltaT the ability = to solve for the temperature increase, DeltaT. Delta T =3D Q/cM, now if the combined effects of c and m provide 13% = less heat transfer capability than the 50/50 mixture that would = indicated that to carry away the same Q at the same flow rate, the delta = T of NPG+ would need to increase by 13%. So if I were getting 180F with = the 50/50 for the same Q load (and flow rate) then with NPG+, I would = expect 180 *1.13 =3D 203F. Yet, if I understood correct we have reports = that lesser temperatures results noted by users of NPG - this leaves me = a bit puzzled. If my assumption is correct thus far, then I am at a loss to understand = the reports of lesser cooling temps when using NPG+, it would seem just = the opposite would happen, that is - the coolant temperature would = increase.=20 Now, If the coolant temp with NPG+ actually does remain the same (or = decreased) for the same Q and flow rate, then it could indicate the = engine heat load is not being carried away as well as with the 50/50. = IF the reports of lesser cooling temps occurs when switching to NPG+ = are correct, then it would appear to me that the engine must then be = operating under a higher heat load (i.e heat not being transfer to the = radiators as effectively) . This doesn't even take into consideration = the possibly lesser flow rate of NPG+ for the same pump speed as the = 50/50 due to its higher 3 times higher viscosity (at 212F).=20 Yes, I have no problem understanding that boil-over has been eliminated = - but, is NPG actually cooling as well as coolant temps may lead one to = believe? I mean with NPG, I could have a excessive block temperature and = still not have boil-over - but my rotary engine would likely have = suffered damage. What am I missing? Inquiring minds (even old ones) want to know {:>) Ed A ------=_NextPart_000_0008_01C629CD.848549C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Al,

Appreciate your (anybody else welcome = also) views=20 on one other thing that is still bothering me about the use of = NPG. =20

Given that NPG+ has a specific heat of = 0.66 at=20 212F or 20% less than the 0.82 for the 50/50 mixture = and given=20 that NPG+ is approx 7% more dense than the 50/50=20 - then that for the same flowrate for both it would seem that = NPG=20 still has a 13% lesser overall capacity for heat transfer (at the = same=20 temps 212F and flow rates).

Also assume that the engine is produce = the same=20 heat load (Q),lets take alook at what temperature we might see with NPG+ = compared to the 50/50 solution. We have from the oldie but goody Q = =3D=20 c*M*DeltaT the ability to solve for the temperature increase,=20 DeltaT.

Delta T =3D Q/cM, now if the combined = effects of c=20 and m provide 13% less heat transfer capability than the 50/50 = mixture=20 that would indicated that to carry away the same Q at the same flow = rate, the=20 delta T of NPG+ would need to increase by 13%. So if I were = getting 180F=20 with the 50/50 for the same Q load (and flow rate) then with NPG+, = I would=20 expect 180 *1.13 =3D 203F. Yet, if I understood correct we = have reports=20 that lesser temperatures results noted by users of NPG - this = leaves me a=20 bit puzzled.

If my assumption is correct thus far, = then I am at=20 a loss to understand the reports of lesser cooling temps when using = NPG+, it=20 would seem just the opposite would happen, that is - the = coolant=20 temperature would increase.

Now, If the coolant temp with = NPG+ actually=20 does remain the same (or decreased) for the same Q and flow = rate,=20 then it could indicate the engine heat load is not being carried = away as=20 well as with the 50/50. IF the reports of lesser cooling = temps occurs=20 when switching to NPG+ are correct, then it would appear to me = that the=20 engine must then be operating under a higher heat load (i.e heat not = being=20 transfer to the radiators as effectively) . This doesn't even take = into=20 consideration the possibly lesser flow rate of NPG+ for the same pump = speed as=20 the 50/50 due to its higher 3 times higher viscosity (at=20 212F).

Yes, I have no problem = understanding that=20 boil-over has been eliminated - but, is NPG actually cooling as well as = coolant=20 temps may lead one to believe? I mean with NPG, I could have a = excessive=20 block temperature and still not have boil-over - but my rotary engine = would=20 likely have suffered damage.

What am I missing? Inquiring = minds (even old=20 ones) want to know {:>)

Ed A

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