major advance in wb mounting for testing

[BillA]

I retested the SlitEdge and got
0.181psi @ 0.999gpm
vs.
0.15psi @ 0.96gpm by Joe
- I think perhaps Joe's pressure values are compressed
(I have a PolarFLO in the mail so we should get an insight into this matter shortly)

I think Joe is introducing a systemic error by not holding his flow rate constant
going to make it an interesting means of comparison
i.e. given a system flow rate of 1.00gpm w/o a wb,
after insertion each wb will reduce the flow by a different amount,
at which flow the dp and C/W are measured
- so then the basis of comparison for the wbs are the various differences, all wrt an initial flow rate of 1gpm
??
going to have to think more on this, is not quite clear (to me)

[winewood]

Bill.. how did you get your flowrate to .999 accuracy?

[BillA]

I measure in lph to tenths, then divide by 60; those are the results then converted to gpm
- more correctly it should be expressed as 1.00 (copied from spreadsheet), but I take all other measurements to 3 decimal places and run the internal calcs the same way;
then generally round the result down to whatever

the accuracy curve of a Danfoss Mag5000 with a Mag1100 flowtube was previously posted,
in the simulator section ??

[Les]

Originally posted by Cathar
JoeC's information said a T'Bird sized die, which is 120mm^2.

Updated graph for 10x10mm and 12x10mm dies.
C/W(TIM)s of 0.1c/w and 0.083333c/w respectively.
The sums assume a uniform Film Coefficient .
The two cases shown are my guesses at the behaviour of a SlitEdge(3mm) and a PolarFLO(8mm)

[BillA]

JoeC told me yesterday the die area was 140mm²
sorry Les, should have posted

[Les]

Originally posted by unregistered
JoeC told me yesterday the die area was 140mm²
sorry Les, should have posted

Numbers are elusive
No problem; was only a doodling exercise.
Seems more sensible both on the required "h" values to describe JoeC's results and scaling to your values.
From imprint image it appears to be 14x10mm

[RoboTech]

Good work on Joe's part and I understand the desire for repeatable, measurable mounting parameters...

But - if all waterblocks are tested under ideal mounting conditions to obtain accurate C/W data, isn't this creating a false sense of comparison since in real world applications Joe Customer will probably rely on the hardware supplied with the block (bolts, clip, springs, ???) most of which will produce less than ideal mounting pressures.

If the goal of testing is to repeatably measure a waterblocks C/W then fine. But that data is then used to compare one block against another - still good info under ideal mounting conditions. But at the end of the day it doesn't necessarily provide a good indicator of how one block will perform vs. another under real world mounting conditions. Block A may have good heat transfer abilities and a poor mounting arrangement while block B has an excellent mount but poor C/W. So which is better for the end user???

[BillA]

quite separate issues
why combine their effects ?
how do you tell one from the other ?
a mounting system can be improved/modified, the wb is as it is

lapping is a quite similar issue
test 'out of the box', or after lapping to do what the mfgr could not be bothered to do ?
(if in fact one actually is capable of making an improvement, sometimes yes - other times no)

most here are interested in the wbs' performance capability and to measure that one needs a repeatable mounting system

providing truly accurate info for newbies (no offense meant) is not possible as one would have to apply too much and too little grease, tighten unevenly, apply all combinations of bending moments from the hoses, etc. etc.

just view wb tests as describing the wb's best possible performance - always relative to that specific test bench