Numeric Calcs for CPU Heat Removal

[BillA]

another from the estimable Arjan Wijdeveld

http://www.home.zonnet.nl/wijdeveld/cooling/part1.pdf
"The follow up (part 2) is scattered in the Vapochill forum (like in http://forum.vapochill.com/showthrea...&threadid=2819 )"

many ways to skin a cat

[Jabo]

I absolutely loved these bits

• the flow conditions are different, for a gas flow a turbulent mixing behaviour has been
assumed, while for water blocks a laminar flow is more appropriate.
• On the interaction zone between water and copper block a boundary layer restricts the
water flow.

and

The model doesn’t take heat transfer restrictions by a laminar boundary layer into
consideration. This isn’t a mayor issue, because the driving factor for heat removal in a
water block is the water velocity.

unregistered, are you sure you want to post this link here?

[BillA]

was posted for comment
??
and that seems to be what you are doing, no ?
feel free

[Jabo]

I rhought I asked you a question didn't I?

What comment? I gave up trying to explain basics of fluids physics and thermodynamics - was deemed to be non-contributory.

If a researcher in an opening statement writes complete bs as basis for his/hers further divagations it tends to render any further content a waste of time....


Jabo

[BillA]

where is this going Jabo ?
you asked a question, I answered
you made a comment, and ?

if Arjan chooses to answer your post . . . .

have you poked around here ?
- try a search for posts by Arjan, he explains some of his rational

understand something Jabo, I promote and assist testers because I believe better data is of value
I will put up a link to testing for the benefit of others (obviously I saw it to have the link)
I do NOT 'vet' others work, that is for the reader

feel free to continue your commentary/critique

[Jabo]

You right, it is going nowhere... it just got me wondering why do ypu post links to article/testing results based on assumption that boundaey layer does not play a significant role in thermal transfer...
We all know that thinning the boundary layer is waht all the water block design and construction is about (and surface area).
It is like saying that it does not matter how many furr coats you put to protect yourself from icy wind since your comfort/temp is mainly/solely depenmdant on the speed of wind.....
It also got me thinking on a wake of L3D's review/preview article so ruthlesly humiliated by members here for use of pompous vocabulary hiding meritorical incoherence.
In my opinion the link posted by you is much more dangerous since the author is an engineer (and not thermal management one) and makes his smoke screen off sophisticated testing methods and fancy visualisations propped by lots of measuring using in-build MoBo thermometers put in nicely done tables.

Anyway, that's just me being picky I guess.

I voiced what was troubling me and that's it. Want to discuss, feel free

[BillA]

you are not the first to express these concerns
did you look for the thread ?

while I do not agree with some of the assumptions, the discussion was conducted in a rational manner by someone who does understand what they are doing - assumptions notwithstanding
l3d is not capable of such

that I post a link means only that, no endorsement other than my interest and possibly that of others

[Jabo]

I looked for user name you quoted and request was returned with 'invalid user name' answer
EDIT:Oh yes, vapochill for some reason I was looking here at Pro Cooling

[BillA]

and I don't know what moniker he registered under,
but he has posted about that paper here
sorry

anyone ?

[Jabo]

Trace testing was quite interesting I must admit.
Does he have an acces to radioactive markers? and X-ray filming equipment?
That's the best way to trace-test in liquids (widely used in medical sciences on cellular level and down).
I did not see any discussion on his numeric model and his assumptions being reviewed.

[Incoherent]

I think that Wijdevelds model is flawed, but at least it is a model, and from what little I have read of him posting, he is the sort who is happy to accept this and make adjustments. The biggest thing for me is that, at least he has a model. It can be used as a guide.
Jabo, your comments on another thread have triggered work on a model of my own. It's Excel based, takes 15 minutes to recalculate after a baseplate thickness change, and gives the wrong results. Not particularly useful at this point but I am working on it.
I would be very interested in hearing (Jabo, Bill, Les, Cather, Wijdeveld, anyones) input on such a thing. I want a waterblock simulator.
Q1. Does power density within a medium follow the inverse square law of propagation?

[Jabo]

Originally Posted by Incoherent

I think that Wijdevelds model is flawed, but at least it is a model, and from what little I have read of him posting, he is the sort who is happy to accept this and make adjustments. The biggest thing for me is that, at least he has a model. It can be used as a guide.
Jabo, your comments on another thread have triggered work on a model of my own. It's Excel based, takes 15 minutes to recalculate after a baseplate thickness change, and gives the wrong results. Not particularly useful at this point but I am working on it.
I would be very interested in hearing (Jabo, Bill, Les, Cather, Wijdeveld, anyones) input on such a thing. I want a waterblock simulator.
Q1. Does power density within a medium follow the inverse square law of propagation?

I'd make a simpler model based on thermal resistance equation (temp drop/increase dependant on thickness assuming uniform spherical model of propagation)




EDIT: Removed half-cooked preliminary sketch desing to avoid unecessary attitude/ego showing offs

[BillA]

have you encountered Electronics Cooling ?
the rest of the world sees it a bit differently

[Jabo]

and...?

P.S. Electronics Cooling, what's that? I thought we are taling here about the best ways of cooling beer cans, he he he

[pauldenton]

Originally Posted by unregistered

and I don't know what moniker he registered under,
but he has posted about that paper here
sorry

anyone ?

i believe he is registerred here as wijdeveld
http://forums.procooling.com/vbb/member.php?userid=6305
http://forums.procooling.com/vbb/showthread.php?t=9532