CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   Model of heating of computer heat sink with pcm (http://www.cfd-online.com/Forums/fluent/44921-model-heating-computer-heat-sink-pcm.html)

anthro June 5, 2007 02:53

Model of heating of computer heat sink with pcm
 
Hi, has anyone done modelling of heat sink with pcm(phase change material) inside.

I am doing a model of a rectangular shape enclosed heat sink heated from below with pcm inside.

Anyone has done something similar? so that i can compare the parameters.thanks!


AJ June 11, 2007 09:09

Re: Model of heating of computer heat sink with pc
 
There is a method mentioned in flotherm site about how to do it.... www.flomerics.com/flotherm/technical_papers/t249.pdf

You have to use enthalphy method and represent effective sensible heat for the PCM with respect to temperature.

Solve it using transient study and you should monitor T vs, time to see if there is any effect....

It should not be hard to follow this method for Fluent.... I used Icepak environment and was successful...

Why do you want to use PCM in your heat sink?

ENjoy, AJ


anthro June 12, 2007 11:21

Re: Model of heating of computer heat sink with pc
 
Thanks alot AJ!

We are experimenting using PCM in heat sink to delay the temperature rise in the heat sink.. Cos you know that PCM has high heat of fusion capacity.

AJ June 12, 2007 14:46

Re: Model of heating of computer heat sink with pc
 
You might need large thermal mass for this to be really effective. Also make sure that larger heatsink surface are is in contact with the phase change material, else melting will be delayed.

Could you use metal mesh or metal foam filled with PCM that could be highly effective?

Just few thoughts...

Bye AJ

anthro June 13, 2007 04:03

Re: Model of heating of computer heat sink with pc
 
Hi AJ,

This is exactly what i am trying to do!!!

We are experimenting on how to increase the heat transfer rate in the PCM by using fins.. As you know, PCM has low thermal conductivity, so we have to use fins.. What we are doing now is experimenting with different kinds of fin configuration.

Do you also have an interest in this research area? If so, I shall send you my paper once i complete it in a few months time.. I am a final year engineering student at Nanyang Technological University singapore.

rgds, Anthony


AJ June 16, 2007 14:13

Re: Model of heating of computer heat sink with pc
 
I work on electronics cooling and have interest in all topics related to it... It will be interesting to see how you come up with new methods to achieve high effectiveness of PCM etc... Are you trying to cool electronics using this PCM? Making good methods of enhancing the conductivity and thermal mass is key to success... Could you guys use porous metal mesh (poco foam... or metal mesh brazed to heat sink base) or other forms and fill it with PCM material?

What's the application?

Thanks, AJ


anthro June 19, 2007 08:05

Re: Model of heating of computer heat sink with pc
 
Yo AJ,

Yeah, u are right!! The main challenge here is that the PCM's generally have very very poor thermal conductivity!

So far my results aren't very encouraging.. Stuff like increasing the number of fins increase the melting rate of th pcm and things like that.. Very general results.. I was thinking of some type of composite arrangements also(like a metal mesh)

At the end of this experimentation i am hoping to come up with something that will significantly increase the heat transfer along the pcm fluid..

We are doing testing based on the specs for a pentium 4 processor, meaning our power input and size of the heat sink will ensure that it fits into a pentium 4 mother board.

I have just ordered some PCM for germany from a company called rubitherm.. Once it arrives i can can start doing experiments in the lab with a real fin.. Hopefully from there, we will be able to get some ideas for modifying the fins!

rgds, Anthony


All times are GMT -4. The time now is 00:13.