airflow modeling program?

[valiskeogh.livejournal.com]

anyone know of any program that can model, at least rudimentarily model, the airflow within a computer case?

i'm trying something new with my setup.

i switched some fans around, and here it is as it stands now:

fans blowing into the case: (intake)
one fan bottom front
one fan on bottom panel
one fan on windowed side panel
two fans top rear just below the power supply
(5 80mm fans total blowing into the case)
exhaust fans:
power supply fans (dual fan)
one 120mm fan on top panel blowing straight up
(2 80mm and 1 120mm fan for exhaust)

the working theory is, cool air comes in through side, front, back and bottom, and hot air is exhausted through the power supply, and fan at very top of case (warm air rising, yadda yadda)

it would be interesting to have a program that could model this airflow.

thanks,

valis
*system specs:
asus p4s800d deluxe mobo
3.2 gig northwood, gigabyte 3d cooler ultra cpu cooler
dual radeon 9000 video cards (one agp, one pci)
2 cd rom drives (both writers)
4 hard drives*

Comments

[inahandbasket]

general concensus among the people who know such things is that you should blow in bottom front/sides and blow out top-back and top.
Modeling airflow is waaaay too complex for a simple program to get remotely right. Too many variables.

[japester.livejournal.com]

or more to the point, there are such things available but unless you have thousands of $$$ spare, you won't find one.

You have a bunch of fans in there, that's probably enough. If you want to get practical, get some smoke and watch it travel through the case. Watch for eddies. It'll give you an answer much quicker than any software could. and it's infinitely cheaper.
The finer the smoke particles the better too. A fog machine'd be best but not all of us can get out hands on one. Kerosene maybe? failing that, a freshly put out match will work.

[jahbulon.livejournal.com]

Isn't it a non-linear equation? I'm pretty sure that air turbulence can only be modeled using chaos maths...

[normie.livejournal.com]

I generally prefer more exhaust fans then intake. It cuts down on the dust inside the case, and if the air outside the case is warm (say in the summer), it's supposed to be more effective to be pumping more warm air out then you're sucking in.

Everybody has more sex than me!

[taleya.livejournal.com]

(and yes, the subject line sounds OT, but the original poster will get the joke :P)

I generally play it by ear - pretty much you need to see it as fresh air comes in front, exhaust out the back. Basically find out where your hotspots are in the case, then cool 'em :) you can usually judge it by hand, and also the airflow strength. If your cd rom drives put out a lot of heat, the blowhole is a good idea as airflow is usually nonexistent up the top of the case.

Fan mesh is also your friend. I got some aluminium mesh from PC Case Gear (http://www.pccasegear.com) and it's easier than vacuuming the case grill - i can just pull those bastards out, wash them in the sink, dry and stuff them back in. You only need them on intakes, as you don't exactly want the exhaust *catching* all the crap it's supposed to be blowing out of your case...

With your setup, I'd say have the back blowing out. With dual video cards, and a fan right next to them (same with the side to a lesser extent) all they're doing is sucking in cool air.....then blowing it right over a heat source and all over the interior of your case. Much like a hairdryer.

If you had an example of the interior of your case, i could probably get a better idea. Got a linky?