Mailing List flyrotary@lancaironline.net Message #30534
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] Tracy delta T ard rad cooling setup
Date: Mon, 6 Mar 2006 09:38:00 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster