Mailing List flyrotary@lancaironline.net Message #35074
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: Ideal cooling
Date: Fri, 5 Jan 2007 07:46:37 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
 
 
Like most things regarding our hobby - it all depends on objectives and compromises.  Efficiency  at the component level does not necessarily equate to system effectiveness. As an example,  You could have a 100% efficient (ok 99% - since nothings perfect) radiator but if it is too small for the heat load its required to dissipate, then the system will not be effective.  On the other hand you can have a radiator that is only 40% efficient  but if its large enough it will still dissipate the heat load - enabling flight.
 
I think its clear that the cooling system needs to be designed for its intended operating environment as well as the engine installation.  If I were hauling heavy loads out of mountain valleys at high density altitudes I would certainly design a system to deal with high power, high heat dissipation with low airflow and air density conditions.  If I were designing a system for a 250+ MPH cruise aircraft I would not use the same design as for the "bush" plane.  For the first, I would want the utmost heat dissipation - screw the drag (I'm not going fast anyhow).  In the second, drag would be of much higher concern in my opinion. 
 
Trying to make an inadequate cooling system functional by using a different coolant is simply not going to work, but people keep trying.  If pure water is not doing the job, then using liquids with a lower heat specific is only going to make it worst.  Just my opinion.
 
 
Ed
 
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster