Data Center Simulation - Cold air containment problem

[JRangel]

Hello everyone!

I’m currently simulating different containment strategies for data center cooling. I successfully developed the open aisle model, and it seems to be working quite well:

Now I’m working on the Cold Aisle Containment (CAC) configuration, which involves isolating the cold aisles to prevent hot and cold air from mixing — a phenomenon clearly visible in the open aisle case.

I’ve used the same boundary conditions for both simulations. However, in the CAC setup, I’m getting very strange results:

A massive pressure differential develops between the aislesAir speeds exceed 60 m/s (???)
The direction of the pressure gradient looks incorrect, especially considering that the supply air is coming from the underfloor plenum

Here’s an example of what I’m seeing in the CAC simulation:

I’m honestly lost at this point. Has anyone experienced something similar? Any ideas on what might be causing this would be hugely appreciated.

Link to the project: https://www.simscale.com/workbench/?pid=2279780503123522622 (“Data center Simulation V2”)
Thanks in advance!

Cheers!

[igaviano]

Hi @JRangel, thanks for posting

Regarding the pressure drop, that’s completely expected in my evaluation due to your porous media assigments. Porous media will basically stablish a pressure difference between its ends.

Regarding the high velocity, I can only guess - but it seems related to the air being trapped in the racks and there being a power source there. Locally, the air will heat up quite a bit and buoyancy effects might be at fault for the higher velocity.

We can also consider that your simulation might not be converged locally, this is always a possibility.

As a final note, we do have this project as a template if that would help: Data Center - Master (Do Not Edit) by dlynch | SimScale

Cheers
Igor