X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5603204 for flyrotary@lancaironline.net; Sat, 16 Jun 2012 08:08:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=2.0 cv=KKDY/S5o c=1 sm=0 a=g3L/TDsr+eNLfIieSKfGkw==:17 a=AHkS0RJitIMA:10 a=ahKODXWJuZoA:10 a=05ChyHeVI94A:10 a=ayC55rCoAAAA:8 a=-TWXWfuBAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=3oc9M9_CAAAA:8 a=oCcaPWc0AAAA:8 a=Or1P3dcUN437h5r6kD4A:9 a=wPNLvfGTeEIA:10 a=dVayXz7UDosA:10 a=U8Ie8EnqySEA:10 a=-YQjl_HWzhM82wY0:21 a=_BY6p50tKwqEaePG:21 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=E93lBu2AAAAA:8 a=Qrh2G4ulzcPJf9lbSvQA:9 a=_W_S_7VecoQA:10 a=tXsnliwV7b4A:10 a=nUeL8I0NP2cA:10 a=EJOIuSjns5AA:10 a=Gia_nvHtrUUA:10 a=ZVDG_fR0YGkA:10 a=KmFi6mcVf10A:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=MpuOTR30KwMA:10 a=ITy1QvswKHoA:10 a=mvWFUSSifWkA:10 a=C1REVoR1p7wA:10 a=NWVoK91CQyQA:10 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:58623] helo=EdPC) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id A0/53-05395-9077CDF4; Sat, 16 Jun 2012 12:07:37 +0000 Message-ID: <2621706ACD1540FC97113F0E861C9CB8@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Coolint Tip and Tricks by Stewart Warner - good reading.: [FlyRotary] Re: inlets and outlets Date: Sat, 16 Jun 2012 08:07:24 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0025_01CD4B97.0FFFCE20" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0025_01CD4B97.0FFFCE20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Here is a link to Steward Warner site with tips and information on = radiator parameter. Very good information http://www.stewartcomponents.com/Tech_Tips.htm Select a Tech Tip from below: Tech Tip #1 - Water Pumps & Pulleys Tech Tip #2 - Radiator Caps Tech Tip #3 - Thermostats & Restrictors Tech Tip #4 - Coolant, Fans, and Hoses Tech Tip #5 - Radiators & External Plumbing I've found no better, credible source of information that is easy to = understand - the best part -> no math required {:>) Regarding double pass radiators - like anything else there are pros and = cons. Here is an extract from that site: Double pass radiators require 16x more pressure to flow the same volume = of coolant through them, as compared to a single pass radiator. Triple = pass radiators require 64x more pressure to maintain the same volume. = Automotive water pumps are a centrifugal design, not positive = displacement, so with a double pass radiator, the pressure is doubled = and flow is reduced by approximately 33%. Modern radiator designs, using = wide/thin cross sections tubes, seldom benefit from multiple pass = configurations. The decrease in flow caused by multiple passes offsets = any benefits of a high-flow water pump. The one basic equation of heat transfer Q =3D mDT/Cp. So if you reduce = the mass flow m by 33%- that is going to have equal reduction in heat = transfer (Q). Now if the double pass causes a better DT then you = recover some of the heat transfer, but all 33% lost to less mass flow? Now if you can get the flow back up then the double pass offers = benefits. A higher capacity/higher pressure pump capable of producing = 16 times more pressure - or some means to increase flow would seem = desirable. =20 The bottom line is you can not consider just one aspect of a cooling = system and overly optimize on it. You cooling system is exactly that - = and it is a system which is no better than the weakness link in the = cooling chain, be it coolant flow, heat transfer characteristics (# = fins/sq inch, thickness, surface area, etc), air flow, specific heat of = coolant and on.=20 Frequently you will find (as Tracy recently pointed out) that it is = the small details that makes one system successful and another seeming = similar system not. =20 Will a double flow work - certainly it will - given enough heat transfer = surface and airflow across it almost any cooling system can be make to = work. The question is what (as always) are the trade offs? Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com From: Thomas Mann=20 Sent: Friday, June 15, 2012 11:17 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: inlets and outlets The double pass radiator increases the efficiency of the radiator by = about 50%. You have tanks on both sides. One side has a partition in the tank with = the inlet at the top and outlet at the bottom. The coolant flows across the top half of the core into the = non-partitioned tank then back across the lower half back to the = partitioned tank and out the outlet. That's the way I went with a custom Ron Davis radiator.=20 On Fri, Jun 15, 2012 at 9:49 PM, wrote: I can certainly see the logic in a single pass radiator of in on top = and out on bottom. With a dual pass design (tanks top and bottom) what would be the = advantage of inlets and outlets on the bottom -vs- the top in a case = with the water pump above the top of the radiator? In both cases their would be a vent line to the swirl pot from the top = tanks. ...C&R No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2180 / Virus Database: 2433/5072 - Release Date: = 06/15/12 ------=_NextPart_000_0025_01CD4B97.0FFFCE20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Here is a link to Steward Warner site with tips = and=20 information on radiator parameter.  Very good = information
 
http://www.stewar= tcomponents.com/Tech_Tips.htm
 
Select a Tech Tip from = below:
Tech Tip #1 - Water Pumps & = Pulleys
Tech Tip #2 - Radiator Caps
Tech Tip #3 - Thermostats & = Restrictors
Tech Tip #4 - Coolant, Fans, and Hoses
Tech Tip #5 - Radiators & External=20 Plumbing<= /A>
I've = found no better,=20 credible source of information that is easy to understand -  = the best=20 part -> no math required {:>)
 
Regarding double pass radiators - like anything = else there=20 are pros and cons.  Here is an extract from that site:
 
 
Double pass radiators require 16x = more pressure=20 to flow the same volume of coolant through them, as compared to a single = pass=20 radiator. Triple pass radiators require 64x more pressure to maintain = the same=20 volume. Automotive water pumps are a centrifugal design, not positive=20 displacement, so with a double pass radiator, the pressure=20 is doubled and flow is reduced by = approximately=20 33%. Modern radiator designs, using wide/thin cross sections = tubes, seldom benefit from multiple pass = configurations. The=20 decrease in flow caused by multiple passes offsets any benefits of a = high-flow=20 water pump.
The one basic equation of heat transfer Q =3D = mDT/Cp.  So if you reduce the mass flow m by = 33%- that is=20 going to have equal reduction in heat transfer (Q).  Now if the = double pass=20 causes a better DT then you recover some of = the heat=20 transfer, but all 33% lost to less mass flow?
 
  Now if you can get the flow back up then = the double=20 pass offers benefits.  A higher capacity/higher pressure = pump capable=20 of producing 16 times more pressure  -  or some means to = increase flow=20 would seem desirable. 
 
The bottom line is you can not consider just one = aspect of=20 a cooling system and overly optimize on it.  You cooling system is = exactly=20 that - and it is a system which is no better than the weakness link = in the=20 cooling chain, be it coolant flow, heat transfer characteristics (# = fins/sq=20 inch, thickness, surface area, etc), air flow, specific heat of coolant = and=20 on. 
 
  Frequently you will find (as Tracy = recently pointed=20 out) that it is the small details that makes one system successful and = another=20 seeming similar system not. 
 
Will a double flow work - certainly it will - = given enough=20 heat transfer surface and airflow across it almost any cooling system = can be=20 make to work.  The question is what  (as always) are = the trade=20 offs?
 
Ed
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

From: Thomas Mann
Sent: Friday, June 15, 2012 11:17 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: inlets and = outlets

The double pass radiator increases = the=20 efficiency of the radiator by about 50%.
You have tanks on both sides. One = side has a=20 partition in the tank with the inlet at the top and outlet at the=20 bottom.
The coolant flows across the top = half of the=20 core into the non-partitioned tank then back across the lower half back = to the=20 partitioned tank and out the outlet.
 
That's the way I went with a custom = Ron Davis=20 radiator.=20


On Fri, Jun 15, 2012 at 9:49 PM, <CozyGirrrl@aol.com>=20 wrote:
I can certainly see the logic in a single pass radiator of in on = top and=20 out on bottom.
 
With a dual pass design (tanks top and bottom) what would be the=20 advantage of inlets and outlets on the bottom -vs- the top in a case = with the=20 water pump above the top of the radiator?
 
In both cases their would be a vent line to the swirl pot = from the=20 top tanks.
 
...C&R

No virus found in this=20 message.
Checked by AVG - www.avg.com
Version: 2012.0.2180 / = Virus=20 Database: 2433/5072 - Release Date: 06/15/12

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