New block design, low profile, hard lined
 

Hi guys, this is my attempt to make a low profile block for socket 478.
The jets will be configurable by making several mid plates..
I will pump this with a Laing Dcc 1-t Plus, and the loop should be pump--> cpu --> Nb --> GPU --> G-Ram --> Rad --> Res

The reason i have chosen to excavate the fluid through the side is that i can go directly to the northbridge block witch will be a simple pass through 10mm id..

I may or may not solder ears on the block to hold it via the holes in the mobo but that will be designed at last so i can make up my mind..

Bp thickness is 2mm with total size being (LxWxH) 50x50x30-40mm, mid plate is actually just 3x3mm acrylic plates glued together with acrylic cement, top is 10mm high with a chamfer so it is basically hollow.. Engine gasket compound will be used to seal it and 4 4x30mm hex bolts to lock it together..

Re: New block design, low profile, hard lined
 

VRML file/iges or stl/ ACIS components something like that would be useful.

Tubes are too long i think (might be guilty of cad makign things look odd here). Would want proper chamfer deepish holes to improve performance.

Re: New block design, low profile, hard lined
 

This is just a Inventor render, but i'll make the dwg files available if someone want's them.. I can make a zip file with the whole package, that would be Inventor files ie. .iam, .ipt as i haven't made the dwg files yet... The reason the tubes are so long is that they have to be so close to the base as possible, 1 mm from them atm... but bottom plate could be made 2 mm lower, it was just to acommodate the 12mm copper tube without it breaking, but 2 mm "flesh" on either side should suffice..

Re: New block design, low profile, hard lined
 

I would be interested in those Inventor files. :)

Re: New block design, low profile, hard lined
 

The trick for jet blocks is to work on the relationship of jet flow velocity, back pressure and size.
Tubes that long with small IDs, even with 25 of them, will have significant back pressure.

The colouring suggests the top bit is made of copper also, but would suggest this not be the case given the shape...

Re: New block design, low profile, hard lined
 

Can prove that you always gain in jet blocks by having smaller jet diameters and more jets, than less.

The main factor of trade off between back pressure and performance is the jet plate spacing parameter (how far the jet exit is for the base).

I believe Incropera and DeWitt suggest (heat transfer book highly recommended, http://www.amazon.com/gp/product/047...Fencoding=UTF8) suggest for turbulent jets i.e. air jets (Re > 2000, think G7 is of order Re=100. so jets at exit from the nozzle do not have turbulent velocity components) that optimal spacing for parallel flat plates where the top one has holes in it to create jets is 5*D (where d is jet diameter). The optimal spacing of the jets in a square grid arrangement is 3 d’s apart. This will not be the case for water but it gives you an idea of the numbers we are talking of and that there is a maximum.

Jets not far enough apart interfere with each other and there is lower jet velocity (probably dominating factor) as mass flow rate is conserved

Mass flow jet = mass flow total / number of jets.

If the jets are too far apart cooling performance declines far away from directly below the nozzle performance declines.

High plate spacing and the jet starts to break down by friction with fluid (5D’s is high for a water jet, think it is more like 1D for water but just speculating).

Low plate spacing and performance does rise (can achieve spectacular heat transfer coefficients per unit area) but pressure drop also increases as the jet impacts the base plate and changes the direction quickly.

Pressure drop could probably be calculated for a single jet by a analytical solution of the Navier Stokes equation but you would need a degree in engineering and about 20 sides of a4 to do it properly. Multiple jets also muck it up some what. Expelling spent (heated up water) is hard and a major problem with jet designs.

NB most jet systems I have seen use a plenum (is that the right word?) where the nozzle tube is large till the end where it exits through a very small hole (dia tube about 3 times larger than hole I think sometimes 10 but these are wild guess of fuzzy memories). This minimises nozzle pressure drop and results in different flow properties.

Water exiting the hole is now un-developed (velocity across the diameter is flat) and you don’t get the pressure drop from the flow developing.

If you have a nozzle tube of over 10 dia’s then the flow is fully developed (has an x^2 distribution ie

Ujet(r) = Umax(1-k*r^2). Velocity is 0 at the walls according to classical theory. K is a constant of some sort

Because jet centreline velocity is now faster you get an increase in performance of about 5% BUT the pressure drop to achieve this is not worth the pay off.

Re: New block design, low profile, hard lined
 

@Bobo5195, Well as far as making complex calculations as to how many jets, im basically too lazy.. And i have no knowledge whatsoever about it, and will not pretend to.. I just saw some of the designs that were made by different people, and hoped to take some from the best of them..

@Long Haired Git: Yes the concept would be to make it all copper, even the top.. for it's soldering ability tbh..

So my plan was as follows:
Jets for having high pressure water shots directly at the base, with the base as "uneven" as possible to cause turbulence, but at the same time making it as low as possible to be sure that it would fit my custom case, that is on hold atm due to finances... (I really can't continue without pump or rad as the case relies on rad for strength and the pump must have a new top made specifically for that case and the top glued to the case).
And the most of the fabricating would be made by hand, so that rules wild cnc milling out.. (To do so i would have to program it by hand as i work by a 4 axis mill atm, and they're custom software and made for wood) :bawling:

Atm jets are 2,5mm id, but might change them to 1mm or less, if i can find some small enough..

Re: New block design, low profile, hard lined
 

Nice idea.

I'd still focus on making the jet tubes shorter; that's going to hurt the flow, a lot. I'd even consider sacrificing a couple of jet tubes, if necessary, to accomodate the side outlet.

Maybe you ought to reconsider the outlet scheme entirely.

Re: New block design, low profile, hard lined
 

Or just buy that low profile Apogee

Re: New block design, low profile, hard lined
 

bigben2k, the side outlet has been taken care of, the side thickness of the block is roughly 7mm atm and flatline has pointed some details out that i'm working on right now. I cannot make the jets any shorter because i want the outlet to be in the side of the block so i can make the nb block passthrough without makin a U loop from top to top.. Ill make a drawing so you can see the plan..

Long Haired Git, that would be the easy solution, but defies the idea of making them myself.. and it costs more too..