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gmat · 06-26-2002, 04:16 AM

The very same person proved that *pressure* plays an important role.
In short you'd want a high pressure in the waterblock, and a low pressure in the rad.
Considering this, putting rads in parallel will reduce the pressure in each individual rad. So far so good.

Now, it goes without question that higher flow rate means better heat transfer. Why ?
* Increased turbulence
* Higher contact rate between water molecules and rad walls, less "dead spots"
* Better temp gradient through the *whole* water circuit because it's "averaged"
* My fluid dynamic courses are so many years behind i can remember everything

Since putting rads in parallel will divide flow... No good.

So what's to say ?
We could go math-crazy and dump endless thermodynamic equations. (Ahhh my friends Reynolds and Boltzmann)
Or you could test it out

Simply put the 2 rads in series, and without changing anything else put em in parallel.
Beware of tube length and elbows and so on... The ideal would be an "open air" test where rads would sit freely on a bench (to avoid tubing / elbows problems)
Get the temps in both configurations. And post the results here

NOTE: this common mistake of "low flow rate = better temps" has been thrown out in forums zillions times. Should be a FAQ, IMHO.

06-26-2002, 04:16 AM	#18
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	The very same person proved that pressure plays an important role. In short you'd want a high pressure in the waterblock, and a low pressure in the rad. Considering this, putting rads in parallel will reduce the pressure in each individual rad. So far so good. Now, it goes without question that higher flow rate means better heat transfer. Why ? * Increased turbulence * Higher contact rate between water molecules and rad walls, less "dead spots" * Better temp gradient through the whole water circuit because it's "averaged" * My fluid dynamic courses are so many years behind i can remember everything Since putting rads in parallel will divide flow... No good. So what's to say ? We could go math-crazy and dump endless thermodynamic equations. (Ahhh my friends Reynolds and Boltzmann) Or you could test it out Simply put the 2 rads in series, and without changing anything else put em in parallel. Beware of tube length and elbows and so on... The ideal would be an "open air" test where rads would sit freely on a bench (to avoid tubing / elbows problems) Get the temps in both configurations. And post the results here NOTE: this common mistake of "low flow rate = better temps" has been thrown out in forums zillions times. Should be a FAQ, IMHO.