[TR] Interesting cooling system web page

[Jim Muller]

On 27 Sep 2007 at 11:00, Randall wrote:

> > 2. Slower-flowing water is better.
> 
> That IS surprising.

Indeed.  I tried reading that article and eventually concluded that I 
wasn't sure enough of what I was reading to pass judgment.  
However...

Depending on where they took the measurements a lower flow might have 
made it *seem* better.  The lower the flow the more heat will be lost 
*for that particular volume of water* going through the radiator at 
that time.  So if the measurement was predominantly affected by the 
temperature at the outflow from the radiator it would in fact 
register a lower temperature.  This must be true for any given 
radiator operating under any particular conditions (provided the 
radiator is warmer than the ambient air, of course).

It is also true that the lower thermal differential between the water 
and the air necessarily means less total heat loss per time to the 
air.  Similar reasoning says that a higher flow results in lower 
thermal gradients everywhere in the engine.  (This may or may not be 
desirable but it is necessarily true.)  If the primary means of 
getting heat out of the engine is via the radiator, then the maximum 
heat loss per time necessarily requires the hottest radiator.

I'm with Randall.  It doesn't make sense.

-- 
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+



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