X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from hub026-NJ-7.exch026.serverdata.net ([206.225.166.170] verified) by logan.com (CommuniGate Pro SMTP 6.0c1) with ESMTPS id 5732085 for flyrotary@lancaironline.net; Tue, 28 Aug 2012 08:07:06 -0400 Received-SPF: none receiver=logan.com; client-ip=206.225.166.170; envelope-from=jwhaley@datacast.com Received: from MBX026-E1-NJ-6.exch026.domain.local ([10.240.14.56]) by HUB026-NJ-7.exch026.domain.local ([10.240.14.233]) with mapi id 14.02.0309.002; Tue, 28 Aug 2012 05:06:30 -0700 From: Jeff Whaley To: 'Rotary motors in aircraft' Subject: RE: [FlyRotary] Spreadsheet Cooling Section Thread-Topic: RE: [FlyRotary] Spreadsheet Cooling Section Thread-Index: Ac2FFY6CdrgKWs3uRAyouuEumEuyaw== Date: Tue, 28 Aug 2012 12:06:30 +0000 Message-ID: <234B758DE9A64449BEB6BB5D1345CA7A10C04B88@mbx026-e1-nj-6.exch026.domain.local> Accept-Language: en-CA, en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: x-originating-ip: [209.87.232.162] Content-Type: multipart/related; boundary="_005_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_"; type="multipart/alternative" MIME-Version: 1.0 --_005_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_ Content-Type: multipart/alternative; boundary="_000_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_" --_000_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Ed, I don't claim to know how to the fix the equations, was just pointing o= ut what I encountered when using the spreadsheet. The following link provides some equations and graphs for the effects of OA= T on required airflow; it's mostly about designing with fans but principle = is the same. http://www.flexxaire.com/documentation/modern_cooling_system_theory.pdf I think your initial thoughts of picking a mid-point temperature then apply= the *T above/below that point will help the cooling section - HP section l= ooks very good! Jeff : "Ed Anderson" Subject: Re: [FlyRotary] Re: [flyRotary] Spreadsheet Cooling Section Date: Fri, 24 Aug 2012 18:48:53 -0400 To: "Rotary motors in aircraft" [Message Header] [Undecoded Message] No doubt it could stand improvements for sure, Jeff. There are four *T's I employ in the cooling equations. Change in air te= mperature across the radiator, change in air temperature across the oil coo= ler and change in fluid temperature of the coolant and oil as they flow thr= ough their heat exchanger. I have heard of Air *T across the radiator ra= nging from 50-100F, I am currently using a *T of 70F , but I know that Tra= cy has reported a *T of 100F. I am also using *T of 70F for the oil cool= er and that is probably too high. For both fluid *Ts, I am using 16F. IF anyone has reference material or sources that could help me refine those= figures - it would undoubtedly improve the cooling section. As Jeff pointed out for the cooling section there is no input for OAT altho= ugh there is for the power section. My initial thoughts would be to pick some OAT and I'm thinking of 59F (SL standard day temp) as a nominal mid po= int of *T. Then if OAT is above that *T, then to simply subtract the diff= erence between OAT and 59F and reduce the air *T across the radiator by tha= t amount. Conversely if OAT is below 59F then to add that *T to the 70F I = am currently using. By increasing the *T factor more heat is transferred (better cooling) by re= ducing the *T factor less heat is transferred (worst cooling) IF anyone has reference material or sources that could help me refine those= figures - it would undoubtedly improve the cooling section. Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 This message, and the documents attached hereto, is intended only for the a= ddressee and may contain privileged or confidential information. Any unauth= orized disclosure is strictly prohibited. If you have received this message= in error, please notify us immediately so that we may correct our internal= records. Please then delete the original message. Thank you. --_000_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Ed, I don’t claim to know how to the fix the e= quations, was just pointing out what I encountered when using the spreadshe= et.

The following link provides some equations and graph= s for the effects of OAT on required airflow; it’s mostly about desig= ning with fans but principle is the same.

http://www.flexxaire.com/documentation/modern_coolin= g_system_theory.pdf

I think your initial thoughts of picking a mid-point= temperature then apply the DT above/below that point will help the cooling section – H= P section looks very good!

Jeff

 

:

"Ed Anderson" <eanderson@c= arolina.rr.com>

Subject:

Re: [FlyRotary] Re: [flyRotary] Spreads= heet Cooling Section

Date:

Fri, 24 Aug 2012 18:48:53 -0400<= /p>

To:

"Rotary motors in aircraft" &= lt;flyrotary@lancaironline.net>

3D"Message

=

No doubt it could stand improvements= for sure, Jeff.

 

  There are four D= T's I employ in the cooling equations.  Change in  air= temperature across the radiator, change in air temperature across the oil cooler and change in fluid temperature of the coolant and oil= as they flow through their heat exchanger.    I have heard = of Air D= T across the radiator ranging from 50-100F,  I am currently= using a D= T of 70F , but I know that Tracy has reported a DT of  100F.   I am also usin= g D= T of 70F for the oil cooler and that is probably too high. =    For both fluid D= Ts, I am using 16F.

 

IF anyone has reference material or sourc= es that could help me refine those figures - it would undoubtedly impr= ove the cooling section.

 

As Jeff pointed out for the cooling secti= on there is no input for OAT although there is for the power section. = My initial thoughts would be to pick

 

some OAT and I'm thinking of 59= F (SL standard day temp) as a nominal mid point of  DT. = ; Then if OAT is above that DT, then to simply subtract the d= ifference between OAT and 59F and reduce the air D= T across the radiator by that amount.  Conversely if OAT is= below 59F then to add that D= T to the 70F I am currently using. 

 

By increasing the D= T factor more heat is transferred (better cooling) by reducing t= he D= T factor less heat is transferred (worst cooling)

 

IF anyone has reference material or sourc= es that could help me refine those figures - it would undoubtedly improve t= he cooling section.


Ed

 

Edward L. Anderson
Anderson Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104

 

This message, and the documents attached hereto, is intended only for the a= ddressee and may contain privileged or confidential information. Any unauth= orized disclosure is strictly prohibited. If you have received this message= in error, please notify us immediately so that we may correct our internal records. Please then delete the origin= al message. Thank you. --_000_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_-- --_005_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_ Content-Type: image/gif; name="image001.gif" Content-Description: image001.gif Content-Disposition: inline; filename="image001.gif"; size=849; creation-date="Tue, 28 Aug 2012 12:06:29 GMT"; modification-date="Tue, 28 Aug 2012 12:06:29 GMT" Content-ID: Content-Transfer-Encoding: base64 R0lGODdhCgANAPcAAAAAAIAAAACAAICAAAAAgIAAgACAgMDAwMDcwKbK8AAAAAAAKgAAVQAAfwAA qgAA1AAqAAAqKgAqVQAqfwAqqgAq1ABVAABVKgBVVQBVfwBVqgBV1AB/AAB/KgB/VQB/fwB/qgB/ 1ACqAACqKgCqVQCqfwCqqgCq1ADUAADUKgDUVQDUfwDUqgDU1CoAACoAKioAVSoAfyoAqioA1Coq ACoqKioqVSoqfyoqqioq1CpVACpVKipVVSpVfypVqipV1Cp/ACp/Kip/VSp/fyp/qip/1CqqACqq KiqqVSqqfyqqqiqq1CrUACrUKirUVSrUfyrUqirU1FUAAFUAKlUAVVUAf1UAqlUA1FUqAFUqKlUq VVUqf1UqqlUq1FVVAFVVKlVVVVVVf1VVqlVV1FV/AFV/KlV/VVV/f1V/qlV/1FWqAFWqKlWqVVWq f1WqqlWq1FXUAFXUKlXUVVXUf1XUqlXU1H8AAH8AKn8AVX8Af38Aqn8A1H8qAH8qKn8qVX8qf38q qn8q1H9VAH9VKn9VVX9Vf39Vqn9V1H9/AH9/Kn9/VX9/f39/qn9/1H+qAH+qKn+qVX+qf3+qqn+q 1H/UAH/UKn/UVX/Uf3/Uqn/U1KoAAKoAKqoAVaoAf6oAqqoA1KoqAKoqKqoqVaoqf6oqqqoq1KpV AKpVKqpVVapVf6pVqqpV1Kp/AKp/Kqp/Vap/f6p/qqp/1KqqAKqqKqqqVaqqf6qqqqqq1KrUAKrU KqrUVarUf6rUqqrU1NQAANQAKtQAVdQAf9QAqtQA1NQqANQqKtQqVdQqf9QqqtQq1NRVANRVKtRV VdRVf9RVqtRV1NR/ANR/KtR/VdR/f9R/qtR/1NSqANSqKtSqVdSqf9SqqtSq1NTUANTUKtTUVdTU f9TUqtTU1AAAAAwMDBkZGSYmJjMzMz8/P0xMTFlZWWZmZnJycn9/f4yMjJmZmaWlpbKysr+/v8zM zNjY2OXl5fLy8v/78KCgpICAgP8AAAD/AP//AAAA//8A/wD//////ywAAAAACgANAAAINgDxCRw4 EAC+fwgTIjT4DwCAAwIXHlSYkKHDhxEZUpTYEONEjRstOoR4ECRFkSQ5bux4saXDgAA7 --_005_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_ Content-Type: image/gif; name="image002.gif" Content-Description: image002.gif Content-Disposition: inline; filename="image002.gif"; size=857; creation-date="Tue, 28 Aug 2012 12:06:29 GMT"; modification-date="Tue, 28 Aug 2012 12:06:29 GMT" Content-ID: Content-Transfer-Encoding: base64 R0lGODdhCgANAPcAAAAAAIAAAACAAICAAAAAgIAAgACAgMDAwMDcwKbK8AAAAAAAKgAAVQAAfwAA qgAA1AAqAAAqKgAqVQAqfwAqqgAq1ABVAABVKgBVVQBVfwBVqgBV1AB/AAB/KgB/VQB/fwB/qgB/ 1ACqAACqKgCqVQCqfwCqqgCq1ADUAADUKgDUVQDUfwDUqgDU1CoAACoAKioAVSoAfyoAqioA1Coq ACoqKioqVSoqfyoqqioq1CpVACpVKipVVSpVfypVqipV1Cp/ACp/Kip/VSp/fyp/qip/1CqqACqq KiqqVSqqfyqqqiqq1CrUACrUKirUVSrUfyrUqirU1FUAAFUAKlUAVVUAf1UAqlUA1FUqAFUqKlUq VVUqf1UqqlUq1FVVAFVVKlVVVVVVf1VVqlVV1FV/AFV/KlV/VVV/f1V/qlV/1FWqAFWqKlWqVVWq f1WqqlWq1FXUAFXUKlXUVVXUf1XUqlXU1H8AAH8AKn8AVX8Af38Aqn8A1H8qAH8qKn8qVX8qf38q qn8q1H9VAH9VKn9VVX9Vf39Vqn9V1H9/AH9/Kn9/VX9/f39/qn9/1H+qAH+qKn+qVX+qf3+qqn+q 1H/UAH/UKn/UVX/Uf3/Uqn/U1KoAAKoAKqoAVaoAf6oAqqoA1KoqAKoqKqoqVaoqf6oqqqoq1KpV AKpVKqpVVapVf6pVqqpV1Kp/AKp/Kqp/Vap/f6p/qqp/1KqqAKqqKqqqVaqqf6qqqqqq1KrUAKrU KqrUVarUf6rUqqrU1NQAANQAKtQAVdQAf9QAqtQA1NQqANQqKtQqVdQqf9QqqtQq1NRVANRVKtRV VdRVf9RVqtRV1NR/ANR/KtR/VdR/f9R/qtR/1NSqANSqKtSqVdSqf9SqqtSq1NTUANTUKtTUVdTU f9TUqtTU1AAAAAwMDBkZGSYmJjMzMz8/P0xMTFlZWWZmZnJycn9/f4yMjJmZmaWlpbKysr+/v8zM zNjY2OXl5fLy8v/78KCgpICAgP8AAAD/AP//AAAA//8A/wD//////ywAAAAACgANAAAIPgDxCRw4 EAC+fwcQKjxgMCHDhAD+GUQYEcDDhhIzVjwIkSJDfA8zQjxYUWRDixVHmnSI0aHCiS5ZAphJs2ZA ADs= --_005_234B758DE9A64449BEB6BB5D1345CA7A10C04B88mbx026e1nj6exch_--