[CFDer_1]

Hallo all of you,

now I do some simulation for a two stroke engines in Converge, but after running the simulation I got an error of:

"Warning:[3507] A cell pair was created with 41 cells on boundary 1 at -.0350496 .00820997 .000500178. This cell may reduce accuracy or stability. Consider refining the grid in this region"

I searched for this error here in the Forum and found this topic:
Cell pair was created...

and as mentioned in it as a solution, I have increased the embed scale from 2 to 3, but after that I got another error like that:

=================================
= BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
= RANK 0 PID 14776 RUNNING AT LAPTOP-8CE92L6N
= EXIT STATUS: -1073740791 (c0000409)
=================================

So the situation now is the lower embed scale causes an error of "cell pair was created" and the higher embed scale causes the error above.

Does any one of you have faced something like that?
I searched for the error of "bad termination" on the internet and it seems like it is related to the number of the cores during the simulation, but I couldn't figure out the solution.

Some info about my case.

-Grid size=4mm
-Embed scale=2
-Intersections were tested using the animation option with "check triangle intersection in each step" activated and the results were zero.
-Seals were created correctly between the ports and the piston, and between the piston and the liner as it is in the examples.
-Simulation on Laptop Core i7, 32 GB RAM

Please if any one have any tips, I would be thankful

Best Regards,

[bb91936762]

Hey David,


Cell pairing is just used to avoid small cut cells leading to small time steps. It is acceptable to have cell pairs, as long as number of paired cells are small. If the case is not crashing, let it run and check if it is affecting accuracy and where the paired cells occur.

Regarding the "BAD TERMINATION", I am guessing that is due to running out of memory, with more cells you need more memory.

[CFDer_1]

Hello,

thank you very much for your reply.

Is there any parameter in the settings or the case setup in Converge which control or limit the consumption of the RAM?

I know that in Edit> References it is possible to select the number of cores which may affects the RAM consumption, but is it the only parameter or there is something else for this purpose?

Does the MPI play a role in this issue? because in the Edit> References I found that it is possible to select the MPI and on my machine there is INTEL MPI and MS MPI, so which one is recommended?

Best Regards

[bb91936762]

Hey David,


There is no parameter which control or limit the consumption of RAM. The MPI version should not play a role in this issue.

Basu