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Date: Tue, 07 Mar 2006 01:21:48 -0500
From: cbeazley <cbeazley@innovista.net>
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Subject: Re: [FlyRotary] Tracy delta T ard rad cooling setup
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Thanks Tracy;

That answers a lot.
Sounds like you're cooling too well at cruise now - thick rads and all...
I know you're air is split between the oil cooler and evap core on one side,
do you have a rough estimate of the total number of square inches of 
cowl inlet opening going to the
1. evaporator cores

2. oil cooler

and the number of square inches at the bottom cowl outlet?


Thanks Again
Cary


Hi Cary, 
Don't have exact figures on all your questions but here's what I have.  
See answers embedded in message below.
Hi Tracy;

I've been looking at your web/posts of your cooling tests.
The air delta T of 70-80F across the thick GM cores in cruise seemed to
work quite well.

A few questions on your current rad setup:

What are core the dimensions? H x W x 3.75"
 
9 x 9  on left side,   9 x 10 on right.  (not counting tanks)

Inlet size?
 
5/8"

outlet size?
 
3/4"  ( both are in parallel, never had a problem with flow distribution)

Inlet distance from the core?  (2-8"?)
 
3 - 8"  (core is not square with inlet)

outlet distance from the core?  (40"?)
 
Outlet? what outlet?  Air just finds its way to the cowl outlet at 
aft bottom edge.  No room for a discreet outlet so distance is sort of 
irrelevant.  It is a tortuous path but losses are not a big 
factor since velocity out of the rad is about 10% of airspeed in a low 
drag liquid cooling system.  That is why delta T is so high too.   (This 
is a subject of much argument on 'other list' : )

Approximate HP/IAS/water temp at any cruise/climb points?
 
All temps greatly depend on OAT.  Temps rarely stabilize in max power 
climb where HP starts at around 170 (restricted by rpm & fixed pitch 
prop) because HP is dropping due to density at altitude and OAT is going 
down.  Remember that ROC is about 2600 FPM at WOT so these things are 
changing fast.  I climb at an IAS of 120 mph.   Only recently fixed all 
the details on the latest cooling config. so have not done any summer 
testing.  Its working very well though. Can't maintain cruise oil temp 
over 150 F in winter, which is too low, need a cowl flap to bring this up.
Tracy

Thanks
Cary