Learning Forum

[Md Daluar Hussain]

Hi everyone, I am trying to generate multiblock strcutured mesh of a full airfcraft in ICEM CFD. I usually export mesh as cgns format. As total cell count is quite high (approx. 60 - 100 million cells), it takes too long to save and export, even sometimes it crashes after 30-35 minuntes. The desktop I use has pretty good configuration (64GB RAM, 10 cores (20 processors),  NVIDIA RTX A4000 GPU). Is there any way to handle this issue to accelerate exporting time without crashing? Any suggestion would be extremely helpful. Thank You !!

[Essence]

Hello,

In ICEM, Settings > General > Number of Processors, you can increase the number of processors. Did you try it out?

[Md Daluar Hussain]

Hello, Thanks for your reply. Yes, I usually do that. I set maximum number of processors available (20 in my PC) in setting when I save and export. Still I face this problem. 

[Essence]

Then for such high mesh count, I would suggest you to increase your computational resources. If you are using the mesh for Fluent, try using Ansys solver as an option while exporting the mesh. Or one more option is (I do not know if this may be useful to you), try to mesh only the parts of the whole geometry and export them. Then in Fluent, you can append the case files, and merge/fuse them together.

[Md Daluar Hussain]

Thanks for your suggestion. I usually generate grid in ICEM and use it for in-house code.  I  have another off topic question. Is there any way to scale down the whole domain without scaling wall geometry part in ICEM CFD? For instance, I plan to work on my existing domain topology, so that I want to scale down whole domain into smaller size but want keep my aircraft geometry dimension fixed ? Is it possible ?

[Essence]

Yes, you can scale the mesh in ICEM. In Edit Mesh > Transform Mesh > Scale Mesh. It will only scale the mesh and not the geometry or blocking.

[Md Daluar Hussain]

Probably I wasn't clear enough regarding my previous question. Let me try to clear you again. If I scale the mesh, it will scale down aircraft mesh also. Essentially, I want to reduce the domain size only while preserving the mesh properties. For example, if the far field of my existing domain extends to 10L in all directions, I would like to create a new domain from the existing one that has a far field of 5L in all directions (i.e. [-10,10]Lx, [0,10]Ly,[-10,10]Lz to [-5,5]Lx, [0,5]Ly,[-5,5]Lz) .  Basically, I just want to avoid creating a new domain, topology, grid spacings etc. from scratch to get a smaller size domain.