Return-Path: Received: from envelope.rose-hulman.edu ([137.112.8.21] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP-TLS id 576421 for flyrotary@lancaironline.net; Wed, 22 Dec 2004 03:37:40 -0500 Received-SPF: none receiver=logan.com; client-ip=137.112.8.21; envelope-from=madsena@rose-hulman.edu Received: from madsena (pool-64-222-181-139.man.east.verizon.net [64.222.181.139]) (authenticated (0 bits)) by envelope.rose-hulman.edu (8.11.6/8.11.6) with ESMTP id iBM7tYv26455 (using TLSv1/SSLv3 with cipher RC4-MD5 (128 bits) verified NO) for ; Wed, 22 Dec 2004 02:55:38 -0500 (EST) From: "Alex Madsen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Oil Coolers Date: Wed, 22 Dec 2004 02:55:16 -0500 Message-ID: <000001c4e7fb$96053df0$6801a8c0@madsena> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C4E7D1.AD2F35F0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.2627 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_01C4E7D1.AD2F35F0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 1450 Btu/min seems high to me. That is 35HP. Where do these numbers come from, do others agree with this number? Alex Madsen -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Tuesday, December 21, 2004 10:32 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Oil Coolers Subject: [FlyRotary] Oil Coolers I have found some really nice oil coolers for aircraft (and other) at http://lytron.com/standard/he_aluminum.asp They are a little expensive but are suppose to have great performance. Does anyone know how much what the average oil flow rate of the 13b is (Gal/hour) and the required heat dissipation (W) or (BTU/hour) Alex Madsen Alex; Heat dissipation to the oil is between 10 and 11 Btu/min per hp. My opinion is to design for about 75-80% power, so for a NA 13B figure about 1450 Btu/min. I've seen different oil flow rate curves that don't quite agree; but best figure about 12 gpm at 5000 rpm, and fairly linear with RPM up to that point, maybe hits 15-16 gpm at 6500. I've seen one dyno curve that maxed out at about 11 gpm; who knows -different pump, different back pressure. One issue for us with rotarys is the flow rate 30% or so higher than the typical piston engine; so its worth checking the flow - pressure drop data for "stock" coolers designed for piston engine use. Al ------=_NextPart_000_0001_01C4E7D1.AD2F35F0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

1450 Btu/min seems high to me. = That is 35HP.  Where do these = numbers come from, do others agree with this number?

 

Alex Madsen

 

-----Original = Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Tuesday, December = 21, 2004 10:32 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = Oil Coolers

 

Subject: [FlyRotary] Oil Coolers

 

I have found some really nice oil coolers for aircraft (and other) at http://lytron.com/standard/he_aluminum.asp They are a little expensive = but are suppose to have great performance.

Does anyone know how much what the average oil flow rate of the 13b is = (Gal/hour) and the required heat dissipation (W) or (BTU/hour) =

 

Alex Madsen

 

Alex;

 

Heat dissipation to the oil is between 10 and 11 Btu/min per hp.  My = opinion is to design for about 75-80% power, so for a NA 13B figure about 1450 = Btu/min.

 

I’ve seen different oil flow rate curves that don’t quite agree; but = best figure about 12 gpm at 5000 rpm, and fairly linear with RPM up to that = point, maybe hits 15-16 gpm at 6500.  I’ve seen one dyno curve that = maxed out at about 11 gpm; who knows –different pump, different back = pressure.

 

One issue for us with rotarys is the flow rate 30% or so higher than the = typical piston engine; so its worth checking the flow – pressure drop data = for “stock” coolers designed for piston engine = use.

 

Al

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