In order to come up with a specific formula for a specific set-up, one would need:
1.Pump (head, flow rate)
2.Tubing (diameter, thickness, material, length)
3.Waterblocks (how many, size, material, internal lay-out ((the number of tubes, shape, size, height, material, position in relation to the input and output of the waterblocks)))
4.Room temp
5.Radiator size or effectiveness. (if effectiveness unknown, dimensions, number of fins, material, spacing, and flow rate of fan necessary)
6. Flow profile of room (natural vs forced convection, etc. )
With this information, and possibly a small schematic of the layout for natural convection calculations purposes, $180/hr will get any of us Mech. E.s to calculate anything you want to know.
Personally, from my preliminary calculations, I am kind of disappointed in the way these water blocks are formed. Only 73% of the area of the block is actually above 50% effective in removing heat, most are designed with triangular tubing (boo, gimme that surface area, baby!), and there is no profile change in the block to the flowrate. Meaning, it is the same shape from entrance to exit, which is great if the change in temp is low, but since we are trying to get these as cool as possible from as hot as possible, raising some surface area near the exit of the blocks would help get the heat out evenly across the block, instead of having warmer water (from entering the block, heating up initially, and traveling towards the exit) try to cool the block near the exit.
Ultimately, these are all really really small concerns when dealing with such a small area to cool, rendering a relatively small heat removal potential. BUT, in the world of OCing, when ultimately one degree C can do wonders or blunders, and everyone is trying to squeeze the last little .01 ghz from their rig, I would feel like these factors might have been taken into consideration.
That is why I am just going to wait to get my own blocks water-jetted once I have the money.
I know this probably didn't answer your question, so I am going to say this. Go by tests like the links if you really want to get some information. To calculate this properly would take ages and tons of information that is just not available or tedious to come by and use. If you really care, get some college to do a senior project on it and have them optimize the cooling for ya.
My calculations might be off, I kind of half-assed the conversions to three sig figs.
Um.....yeah, I think that covers most of it. I will probably take my time and do a more in-depth view in flow visualization software (if I can torrent). If I do come up with something concrete justifying a different design of a water block, I will probably post it if it costs too much to properly manufacture for commercial use. Otherwise, look for it on shelves within 6 mos.
cheers.