Quote:
Originally posted by myv65
BigBen,
I don't want to put a damper on your quest, but when I see stuff like "200 gph+", I gotta comment. You've already been through the exercise of water's thermal properties. You know that flow rate * delta-T equals power. Taking the relevant units, watts = gph * °C / 0.227 or gph = watts * 0.227 / °C.
This means 100 watts causes a delta-T of 1°C at 22.7 gph. At your "200 gph+", say 227 gph, delta-T for 100 watts is only 0.1°C. This 0.9°C improvement for a 900% flow rate increase is pretty pathetic.
Granted, what matters isn't delta-T in the water but rather delta-T between the die and the water. This still isn't so much a function of volumetric flow rate, though, as it is velocity and surface area.
I realize I'm not telling you anything you don't already know, but it seems you may be straying a little. Just remember, it's all about balancing the entire system and the block is just one part. You could have "the world's best block" and still have a lousy system if the remaining components aren't right for that block.
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No problem, you know that I need to be put back on track, once in a while
Actually, I'm going with
this calculation. This fellow (michael westen, Holland, he might have taken the graph from BillA) gave us some PRELIMINARY numbers, where 200 gph (effective) flow (w/ 5mm thickness) will achieve 3 deg C cooler than 100 gph (w/ 10mm baseplate thickness). I don't believe that going for 300 gph (2mm) is practical, because then the baseplate would be prone to bending under pressure, especially if I slap a pelt on it at 150 to 300 psi.
So here I am, at 200gph+
, 5mm baseplate thickness, figuring out a good fin arrangement, and channel cross section pattern.
What do you think now?