The fl process could not be started.

[rre285]

Hello,

I was trying to run my UDF in Fluent 2023 R2 to do a meltflow simulation. The udf seems to be good, building and loading went good. the initialtization is okay, but whenever I run calculation, I resieve this error: "===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   RANK 0 PID 22572 RUNNING AT a074478
=   EXIT STATUS: -1 (ffffffff)
===================================================================================
 The fl process could not be started."

I am running in parallel mode. I am not sure what is the reason behind this failure.

[Rob]

Can you run any models on that hardware configuration? 

[rre285]

Thank you for answering. Yes I've tried a simpler UDF and it was working fine, so I am not sure if the issue is with the parallel mode or with my complex udf.

[Rob]

If a simple UDF works, it's likely your more complex UDF. Was anything more diagnostic printed before the node failures? The section you pasted is just a node kill message, and I'm expecting something just happened just before that. 

[rre285]

Nothing appeared before, there was a message that hyperid initialization is done then this error appears when I run calculation. So I have changed a little in the settings and this is the new error message that I recieved:

job aborted:
[ranks] message

[0] process exited without calling finalize

[1] terminated

---- error analysis -----

[0] on A074478
C:\PROGRA~1\ANSYSI~1\v232\fluent\fluent23.2.0\win64\3ddp_node\fl_mpi2320.exe ended prematurely and may have crashed. exit code 2

---- error analysis -----
 The fl process could not be started.

[Rob]

No SIGSEV error or the like?

[rre285]

yes, you're right. I just checked again and this is the full error message:

iter  continuity   u-phase-1   u-phase-2   v-phase-1   v-phase-2   w-phase-1   w-phase-2   energy-p1   energy-p2           k       omega     time/iter

==============================================================================

Node 1: Process 24976: Received signal SIGSEGV.

==============================================================================

==============================================================================

Node 0: Process 12484: Received signal SIGSEGV.

==============================================================================

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   RANK 1 PID 24976 RUNNING AT a074478
=   EXIT STATUS: -1 (ffffffff)
===================================================================================
 The fl process could not be started.

[Rob]

OK, so look in the UDF to see what data is being called from Fluent: SIGSEV is often the UDF wants a value that Fluent doesn't know exists. Are you using any UDS or UDM? 

[rre285]

I am using UDMs. I think the issue was that I was using the wrong multiphase model compared to what I introduced in my udf. I ran through my udf again and now it is working. 

Thank you so much for your help.