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Unread 03-29-2003, 06:53 AM   #60
MadDogMe
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The idea of the channel is to increase the surface area. However, there are two problems introduced when you increase surface area with a channel. First, the area that you added is above, not at the same level as, the base. So heat has travel further to get to where it can be transferred to water. This reduces efficiency. So the gain from channels is a balance between increase surface area and lost efficiency, not simply an absolute increase due to surface area. Second, when you have channels, you create drag, which slows down the water. Slower water doesn't cool as well, so again, you've reduced performance.
I think you're overly hung up on the max efficiency thing GS, it's more important to remove more units of heat than remove it at a certain temp. The extra distance heat has to travel is tiny and is greatly offset by having double the surface area(assuming a square shaped channel, more if deeper) for convection to happen...

The drag is neglegable, what difference is there between it and that caused by cross scored 'turbulance' marks?...

PS, have you measured the cross~sectional area of your blocks water channel?, how does it compare to the barb sizes or tube inner diametre?. If it's bigger you'll get a pressure drop, if smaller you'll cause resistance but boost velocity, have you thought about tweaking it to match your pumps power?...
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