[greenman100]

Originally Posted by HammerSandwich

I read that email with the usual dejection until I realized who'd written it. Then I said, "Oh, God!" out loud.

I'd point out his strange assumption that 2 passes through the block must add more heat to the water while 2 passes through the rad must not dump as much. Also aim him at a "heat transfer is proportional to delta-T" article.

here's what I said, note the link to the thermochill article/graph

(on a side note, my emailbox if filling up about the myths)

Originally Posted by email

Thanks for your email.

Maybe I am still a bit unclear.

A radiator WILL benefit from higher flow/speed, in a closed loop system. You see, the slower the water goes, the less turbulence there is. If there is little turbulence, then the water molecules near the metal will cool down, while the water molecules near the center of the pipe/fin will not change temperature as much. As we all know, heat transfer is dependent on deltaT, and if the warmer water molecules don't ever get to the colder metal, then efficent heat reansfer will not happen.

I am rather surprised that an employee of a major waterblock company does not have a better grasp of heat transfer and thermodynamics.

You would probably benefit from the following graphic:

Note that for a given airflow, as coolant flow is increased, heat transfer is increased.

http://www.overclockers.com/articles778/thermo2.gif

from: http://www.overclockers.com/articles778


Also, if it takes a 10x increase in flow to see a change in your waterblocks, I suggest you upgrade your test equipment. Take a look here:

http://www.procooling.com/html/pro_testing.php

and you'll see the test results of various waterblocks.
Performance improves markedly across the .5--->2.0GPM range.

Thanks,
Tim

and his reply:

Originally Posted by email

Thanks for your email.

With regard to turbulent or laminar flow, there are huge differences in radiator designs and their response to the flow velocity of the water. As an example radiators based on cylinder shaped hairpin tubes reacts differently compared to a heater core style of radiators. Furthermore some radiators use corrugated tubing design, why the water will be mixed very well independent of flow velocity.

With regard to flow rate, if you read the document that is based upon real life tests and CFD simulations, you will see that there IS a difference, but in order to see significant changes (which of course is subjective) you would need a much larger flow. For instance moving from a L20 to a L30 or moving from 3/8" to 1/2" does not have a major impact.

I'm rather surprised about your arrogant attitude. I'm sure that our success in this field must be pure luck, as we obviously don't have a clue and thermodynamics... Thanks for learning us!

Thanks,
André

WTF.....