Learning Forum

[seffa]

I am trying to model an airflow system in a mushroom growing room. The racks which contain the mushrooms are complex and the room contains 60 racks. 

 

I have modeled the fluid volume in AutoCAD and brought it into Discovery AIM. I have previously ran the simulation without the racks in it with success. I am afraid the more detailed modeled is too complex.

 

I have ran the physics solver with the complex model and after about 3 hours it failed. I have reduced the solution fidelity and re-ran it, it is still trying to solve it.

 

One thing to note is that in both of these failed cases the solution monitor never displayed any iterations being done.

 

Computer specs are as follows:

Intel(R) Core(TM) i7-8850 CPU @2.60GHz

16.0 GB ram

64-bit, windows 10

NVIDIA Quadro P2000

 

Ive also attached an image of the model being processed, it is about 2 hours in and  still dont see any iterations.

[Brian Bueno]

seffa

You may just be running out of RAM.  16 GB is a relatively small amount.  I would recommend simplifying the model.  It looks like it's symmetric along the length of the room, and you could potentially take half of that remaining portion to get some indication of what the airflow would be like.

You could also set up an analysis with a few of the racks and examine the flow in much greater detail.

[seffa]

Brian Bueno Well ive been monitoring my computers memory and it never gets above 13 GB. It may be the racks or the small holes in the inlet pipes. Theres 56 holes in each inlet pipe. I am going to start with a small scale model and slowing add more elements.

[seffa]

Brian Bueno I get this message: "Pre-Boundary Layer generation has stopped because of side face limitation, proximity collisions and quality."

 

What causes this and how can it be avoided?

[seffa]

"Pre-Boundary Layer generation has stopped because of side face limitation, proximity collisions and quality" is the message i get when i try to run solver. The program then just freezes until i force close it...

[Naresh Patre]

Hello seffa

The message is indicating that the boundary layer mesh generation failed due to the reasons mentioned in the message. You will have to check and modify the mesh sizes to ensure that boundary layers fit within the small gaps in the model. If you are using Physics aware meshing, you will have to add Mesh task to get access to mesh settings. To add mesh task, simply right click on Flow/Physics task and select "Define Mesh Manually" option which will add a mesh task to your current workflow.

Also looking at the small gaps in the model, You may want to reduce the number of boundary layers from 5 to 3.