Error during Simulation Run of CHT

123ankitj · October 1, 2018, 7:14am

I am trying to simulate a CHT through a solid block that is in contact with another block and the heat is convected through this block.
I am facing error during simulation Run 1 of Simulation 2.I cant find the errors through the logs.

I have another issue regarding meshing.The background box doesnot gets meshed even though i specify the material point in the box and out of the solid.

(https://www.simscale.com/workbench/?pid=4747628001988447804&mi=run%3A1%2Csimulation%3A6&mt=SIMULATION_RUN)

jousefm · October 1, 2018, 7:56am

Hi @123ankitj!

It looks that the surfaces of your CAD model rather overlap than touch each other. @vgon_alves, can you assist our user here and tell him how to fix the geometry for best results? Thanks a lot!

Best,

Jousef

vgon_alves · October 1, 2018, 10:19am

Hi everyone,

Thank you very much for tagging me here, Jousef! I’ll take a look at this one and give a feedback asap.

Cheers,

Vinícius

vgon_alves · October 2, 2018, 1:07pm

Hi @123ankitj,

Sorry for the delay.
I found no issues about the geometry, but you have a 0.4mm copper sheet which requires a fine mesh in interaction with the fluid domain. It can be the reason for the memory problem that the solver log is reporting.

 mpirun noticed that process rank 2 with PID 152 on node  exited on signal 15 (Terminated).

Please try to improve your mesh quality and keep me updated on if it works.

Cheers,

Vinícius

UPDATE: I did a test run with the mesh corrections and it worked for now. You can begin defining a region to reffine the mesh as you can see below. Let me know if with your improvements you obtain a better run.

Before

After

123ankitj · October 3, 2018, 5:34am

Thanks i will try that and report back to you.

123ankitj · October 3, 2018, 5:49am

Can you share that project with me as a reference?

vgon_alves · October 3, 2018, 6:06am

Sure!

[Project link]. I set random values for the simulation just for tests, but you can replace the values you want (speeds, heat source etc).

Cheers,

Vinícius

123ankitj · October 3, 2018, 6:19am

Thanks

MKM · October 7, 2018, 6:42am

Hi @vgon_alves
I tried meshing and simulating a similar object but i am getting the following error.
The Courant number (CFL) exceeded the limit of 1. You may experience either instability or bad temporal accuracy. It is recommended to keep the CFL number below 0.7. In order to achieve this you need to decrease the time step.
Copy of Simulation 3 -Run1

vgon_alves · October 7, 2018, 9:27am

Hi @MKM,

I’ll take a look at this one and give you a feedback asap.

Cheers,

Vinícius

vgon_alves · October 8, 2018, 9:08am

Hi @MKM,

Please consider this mindset:

Try to set the velocity at the inlet and the pressure at the outlet (you are doing the opposite), we do not know the velocity profile - which depends on what happened in your stream domain - to set it at outlet.
You can use a symmetry condition on the length of your geometry, this should help you with CFL number.

Please, let me know if it works.

Cheers,

Vinícius

MKM · October 9, 2018, 3:22am

I tried to set the velocity inlet condition and it still show me an error.