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Unread 07-16-2002, 01:07 PM   #7
myv65
Cooling Savant
 
Join Date: May 2002
Location: home
Posts: 365
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Well, first I should clarify that flow wouldn't be laminar in the block you linked with the possible exception of stagnant areas. The reason stuff would tend to stagnant (actually in all but the last couple of tubes) is that fluids don't like changing directions. More accurately, it'll seek the path of least resistance. When the cross flow pathways are of lower resistance than the "manifold" feeding them, the flow will tend to make the long loop. In the picture, the "manifold" has much lower area than the combined cross tubes. Like I said, it doesn't make a whole lot of intuitive sense, but is true nonetheless.

As to what would make a good block, that's the $64K question. It sounds like a cop-out answer, but IMHO there is no single ideal. What I really mean is that there are conflicting properties based upon your own priorities. You want dead silent cooling at stock speed/voltage? Fine, you can do that with < 10 gph and the right block. You want maximum overclocking? Fine, you can do that with > 50 gph and the right block. Obviously, there's more to it than this in that you must also select the right range of pump and radiator/fans (and I'm totalling ignoring things like pelts, etc.).

My own personal bent is towards low volume, low noise cooling without regard to temperatures so long as things remain completely stable. I toy with overclocking a little, but don't get into like a lot of people do. I'll take sub-30 dBA and stock speed any day.

Funny thing is that efficient block design shares many of the same qualities as efficient radiator design. In each case you are trying to balance variable thermal resistances such that the total resistance is a minimum. Reducing one resistance generally raises another. It's a lot like electrical resistors in parallel where the individual resistors must add up to a fixed sum. The lowest net resistance will occur when all resistances have the same value.

Oh yeah, and in my post above I said "rho = 1000 kg/m^2" should have been "rho = 1000 kg/m^3". Sue me.

Last edited by myv65; 07-16-2002 at 01:10 PM.
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