[Lexa]

Hi! I'm a new user of OpenFoam and have a research project that force me to use it.

My project is to make a temperature contour plot from 1 CPU, based on temperature data measured in all 6 sides (front, left, right, back, upside, and bottom.). so, the purpose is to determine the air flow inside the CPU and where's the "hottest" spot on it.

and I want to ask:
1). what solver is the best fit on my project?
2). how to add temperature function on that solver?

any help will be greatly appreciated. thank you!

[alberto]

Originally Posted by Lexa

Hi! I'm a new user of OpenFoam and have a research project that force me to use it.

My project is to make a temperature contour plot from 1 CPU, based on temperature data measured in all 6 sides (front, left, right, back, upside, and bottom.). so, the purpose is to determine the air flow inside the CPU and where's the "hottest" spot on it.

Do you measure the temperature on the CPU (processor) sides, and want the temperature contour plots of air inside the computer case? In such a case, you just need to specify the temperatures of a "box" that represents your CPU, and the air moves around it.
In such a case buoyantSimpleFoam or buoyantPisoFoam are OK. The first gives you a steady solution, the second shows you the evolution in time.

If you need a "coupled" solver, take a look at chtMultiRegionalFoam or conjugateHeatFoam (only OpenFOAM-dev).

Best,

[Lexa]

okay, i try to use buoyantPisoFoam here..
and before i'm starting my project, i try to be familiar with this solver first..
in attachments there are blockMeshDict and screenshot i've taken.

in this case, i try to make block with 2 heat sources inside (named "sensor" in the blockMeshDict) and I set in 310. there's also 1 wall called casekiri, which being set in 298. the air ("patchs") is 300.

i simulate it for time interval 20 and got this screenshot (using slice mode). i think i made some mistakes so the picture is not as i expected, because the heat (higher temperature) seems only in the small cubes and didn't spread to the air..
what should I do if I want to get the heat spreading to all directions
(after 20 times, i hope the temperature of air get higher..)

Thanks--

[alberto]

Originally Posted by Lexa

okay, i try to use buoyantPisoFoam here..
and before i'm starting my project, i try to be familiar with this solver first..
in attachments there are blockMeshDict and screenshot i've taken.

in this case, i try to make block with 2 heat sources inside (named "sensor" in the blockMeshDict) and I set in 310. there's also 1 wall called casekiri, which being set in 298. the air ("patchs") is 300.

i simulate it for time interval 20 and got this screenshot (using slice mode). i think i made some mistakes so the picture is not as i expected, because the heat (higher temperature) seems only in the small cubes and didn't spread to the air..
what should I do if I want to get the heat spreading to all directions
(after 20 times, i hope the temperature of air get higher..)

Thanks--

You can check if you made some mistake by setting the high temperature to a significantly higher value than the air temperature, and see what happens.

How does the air circulate inside? Only natural convection or is it forced?

Best,

[Lexa]

I tried to change the 310 to 400 and (extremely) 2000, but nothing changed.
there's only natural convection..

[alberto]

Originally Posted by Lexa

I tried to change the 310 to 400 and (extremely) 2000, but nothing changed.
there's only natural convection..

Hard to tell what's going on without the case. Try to compare the "hotroom" tutorial with your case and see what's different, or you might set the same temperature difference in your case in the tutorial and run it.

You might need much longer times. If you look at the tutorial, the final time is t = 1000s.

Best,

[Lexa]

Hi, Berto.
hmm.. i think the problem still happened.
Okay, for several times i'll postpone this project first.. and if you have time, please check my new thread (link : http://www.cfd-online.com/Forums/ope...-2-blocks.html).. There's similar problem with this one, so if you can help me with that problem, I'm very sure this problem can be solved easily too.. Thanks.