Learning Forum

[v.bhatnagar.1]

Hello all,

I have been running a viscoelastic extrusion simulation (evolution of relaxation time) on Ansys Polyflow on my University's HPC. It runs properly, but very slowly - 3 days and 20 hours for 4 steps so far. I am currently running it on 8 cores. As I plan to increase the number of simulations and also the domain size, are there practical steps that I can use to speed these simulations? Also, are there ways to reduce RAM usage?

Looking forward to your help! 

[Prashanth]

Hi Vedanth,

Viscoelastic simulations do take longer to run, there's many more equations than any a simple Generalized Newtonian case. If you reduce the grid size by placing the cells judiciusly, you can speed up by not giving up on accuracy much. Also, if you have a GPU card that is supported by the GPU accelerator feature, you can use it to boost the computatioal speed. Another option is to do a distributed memory parallel run on MUMPS solver and run the simulation on multiple nodes.

[v.bhatnagar.1]

 

Hello Prashanth,

Thanks for your reply. I am using Ansys 2024 R1. I will try to reduce the number of mesh elements.

Some queries:

1. Is it possible to tweak the solver (numerical or evolution parameter) settings to accelerate the solution?
2. How can I use the MUMPS solver?
3. How does GPU acceleration work? Does the GPU VRAM need to be as large as the mesh size? Can GPU acceleration work with regular RAM and alongside the CPU? Is there a published comparison between running Polyflow (or Fluent) on a CPU vs. GPU? Please shed some light on this.
4. Can you please recommend a GPU / CPU combination(s) that is known to be compatible with Ansys Polyflow (Ansys 2024 R1)? I can look into procuring a workstation with your recommended configuration. Our budget would be a maximum of 3000 GBP.

I will be performing about 200-300 viscoelastic co-extrusion simulations. If you can answer with this perspective, that would be great.

Please let me know if you need any information from my end.