WW evolution 1
 

20 0.5x5x25mm fins with 19 gaps in between the middle one is 1mm the rest are 0.5mm wide
along the base of each channel 2mm deep holes are drilled.
bottom is copper top 2 layers are polycarb. the pics arent complete (theres only 3 rows of holes rather than all 19.
For pics go Here
any input welcome :)
Si

.5mm thick? Can you really machine something like that?

I think the holes in the channels will do very little, other than getting water stuck in them.

I'd say it would probably work best as a simple microchannel block.

Also this is going to hard to machine, how were you planning on doing it?

Yeah I know its gonna be interesting to make, im planning to use a slitting saw and do several shallow passes, it means itll be very slow to do but it should work.
the holes hopefully will do something with the other idea i had for the middle plate instead of using the single slit i might use a jet plate and with a decent sized pump it should kill all the dead water in the holes. Anyway even if it doesnt work all that well it should be a good experiment to see how far you can take the microchannels.
Si

You are going to have to drill with a 0.4mm bit or so. They are expensive, and will break VERY easily.

Atm I havent found any drill bits of the right size that are anything but hss (which will go blunt far too quickly) but at least if I am forced to use the hss ones their cheap (<70p each) so it wont be as bad if I go through a few. Also the drill can be done in the cnc machine so at least there will be almost no side ways pressure so im less likely to snap them.
Si

but then again: water leads hotness better then copper.

yeah but if i were to use a middle section with holes over each of the holes in the base the speed of the water entering the block would stop these from being dead water.

Sorry I didn't understand that.

i'm not sure that the added design would give you any better cooling, however this would not be that hard to do with an edm. I've been playing with one recently and it's amazing what it can do that a regular mill has a time with.

Copper = old & busted
Water = new hotness?

Anyway, I'm against any sort of passages this small - ~1.0 and 0.5 mm holes and ~0.5 channels will see so much surface tension you'll have slow-moving or stagnant water between the bulk flow through the block and the base.

I'd bet widening the channels or removing them entirely would give you better results.

Alchemy

I think he means water has better thermal properties than copper, as in water leads heat away faster than copper. (which it does'nt :p , it's better than air though ;) )...

Alchemy is making a very good point.... surface tension is a BITCH.

Water is not particularly good at conducting heat, what it is good at, is absorbing heat. and that is what makes it so well suited for thermal management or moving heat.... unfortunately, as much heat as it takes to rise the temperature of a set amount of water, one degree, It would also require getting rid of that same amount of heat, to lower it by one degree, and from there the phenomenon that virtually undetectable changes in water temp can be observed at the inlet and outlet of a block,

then just put a surfactant (sp) like water wetter in the water itll reduce surface tension. and if you put a decent sized pump you are hardly going to get stagnant water the channels maybe be very thin but they are not thin enough to cause the surface tension to go the whole way across each channel