System Coupling Restart Problem

SonyCFD · March 24, 2014, 19:48

Hello All !
I am using System Coupling in Ansys 14.5 for a 2Way- FSI transient Analysis.
I am facing an issue in the restart of the simulations.

Every time I restart, after finishing the first iteration of Ansys structural and fluent the simulation crashes display an error as below -
"pure virtual method called
Terminating/opt/ansys_inc/v145/aisol/.workbench: line 141: 9637 Aborted"

Has anyone come across this.

Thanks !!

stumpy · March 26, 2014, 09:55

What OS are you running on and are Fluent and Ansys structural running in serial, shared parallel or distributed parallel?

SonyCFD · March 26, 2014, 20:41

Hi Stumpy !
I am using Linux (RHEL)

I have tried to restart on two separate Linux machines (one with RHEL 5.7 other with RHEL 6.5) , but in both cases the restart simulation fails after the first coupling iteration and gives the same error (Pure Virtual method called...)

Fluent is running parallel across 4nodes(8cpus) each. I am not sure how fluent uses memory (shared or distributed)
Ansys is running on 1 node (8cpus) in parallel using the 8 cpus using the memory of the same node.

Thanks

stumpy · March 27, 2014, 09:31

Is the restart consistent with the way the first part of the run was completed? I think Ansys (MAPDL) would be very sensitive to any machine or OS change on a restart. If Ansys was run using the distributed option (even though everything's running on the same machine) then you cannot change the number of CPU's on a restart either. Fluent itself should be robust to changes in OS or number of partitions on a restart, but when combined with System Coupling it may not be. If the number of partitions change then it's possible the node numbering on the FSI interface changes, which would mess up System Coupling. Version 15 is more robust for restarts, but you would not be able to restart a 14.5 case in 15.0; you'd have to run from scratch.

March 24, 2014, 19:48	System Coupling Restart Problem	#1
SonyCFD New Member Sony Join Date: May 2010 Posts: 14 Rep Power: 16	Hello All ! I am using System Coupling in Ansys 14.5 for a 2Way- FSI transient Analysis. I am facing an issue in the restart of the simulations. Every time I restart, after finishing the first iteration of Ansys structural and fluent the simulation crashes display an error as below - "pure virtual method called Terminating/opt/ansys_inc/v145/aisol/.workbench: line 141: 9637 Aborted" Has anyone come across this. Thanks !!

March 26, 2014, 20:41		#3
SonyCFD New Member Sony Join Date: May 2010 Posts: 14 Rep Power: 16	Hi Stumpy ! I am using Linux (RHEL) I have tried to restart on two separate Linux machines (one with RHEL 5.7 other with RHEL 6.5) , but in both cases the restart simulation fails after the first coupling iteration and gives the same error (Pure Virtual method called...) Fluent is running parallel across 4nodes(8cpus) each. I am not sure how fluent uses memory (shared or distributed) Ansys is running on 1 node (8cpus) in parallel using the 8 cpus using the memory of the same node. Thanks Last edited by SonyCFD; March 26, 2014 at 20:42. Reason: typo

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March 26, 2014, 09:55		#2
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	What OS are you running on and are Fluent and Ansys structural running in serial, shared parallel or distributed parallel?

March 27, 2014, 09:31		#4
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	Is the restart consistent with the way the first part of the run was completed? I think Ansys (MAPDL) would be very sensitive to any machine or OS change on a restart. If Ansys was run using the distributed option (even though everything's running on the same machine) then you cannot change the number of CPU's on a restart either. Fluent itself should be robust to changes in OS or number of partitions on a restart, but when combined with System Coupling it may not be. If the number of partitions change then it's possible the node numbering on the FSI interface changes, which would mess up System Coupling. Version 15 is more robust for restarts, but you would not be able to restart a 14.5 case in 15.0; you'd have to run from scratch.