Mailing List flyrotary@lancaironline.net Message #57555
From: Gordon Alling <gordon@acumen-ea.com>
Subject: RE: [FlyRotary] Re: Radiators
Date: Wed, 7 Mar 2012 15:33:22 -0500
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>
Yes, I'm running two 13Bs.  One rule of thumb I use is for a typical gas
engine, the total fuel energy is distributed roughly 1/3 to the shaft, 1/3
to the coolant and 1/3 to the exhaust.  Assuming an even 200 HP shaft power,
that puts approximately 200 HP = 510,000 BTU/hr into the coolant.  I don't
know how this distribution changes for a rotary vs. a piston engine.  My
approach is to look for an automotive radiator for an engine with roughly
the same shaft power as the 13B and see how it works.

That aside, I noted that several of the auto radiators that I am looking at
integrate an oil cooler for transmission fluid and/or engine oil.  This
strikes me as rather slick if the ratio of radiator area to oil cooler area
works for the distribution of cooling load in the coolant vs. the engine
oil.  Assuming that 1/3 of the cooling load is in the oil, as a starting
point, I will look for a radiator that has 1/3 of its face area dedicated to
oil cooling.  In the end, I will have to test is and see.

Thanks for the input.

Gordon C. Alling, Jr., PE
President
acumen Engineering/Analysis, Inc.

540-786-2200
www.acumen-ea.com

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Mark Steitle
Sent: Wednesday, March 07, 2012 3:13 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Radiators

Bill,

I don't think Gordon is running a rotary, so the 2/3 - 1/3 rule
probably doesn't apply.  I have no idea what the water-oil ratio of is
for a 4.3L Chevy V-6, but I'd bet that info is available somewhere on
the internet.

Mark

On 3/7/12, William Jepson <wrjjrs@gmail.com> wrote:
Gordon, the oil cooling required in a rotary is higher than a standard
I.c.e. The oil cooling is about 1/3 of the total cooling. There are lots
of
"rules of thumb" on cooling. Typically about 3 ci of heat exchanger per
hp.
That would be divided 2/3 water and 1/3 oil cooling. Ducting changes
things
dramatically but that is a start.
Bill Jepson
On Mar 7, 2012 7:20 AM, "Gordon Alling" <gordon@acumen-ea.com> wrote:

I'm thinking about radiators for my 13B Defiant.  I've noted some
automotive radiators integrate oil and transmission fluid cooling with
the
engine coolant heat exchanger.  Has anyone looked at these as a means of
integrating the oil and water cooler for an aircraft application?  Does
anyone have an estimate of the oil and transmission heat load in a
typical
GMC 4.3 L  Jimmy?****

** **

Gordon C. Alling, Jr., PE****

President****

*acumen* *Engineering/Analysis, Inc.*****

** **

540-786-2200****

www.acumen-ea.com****

** **



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