Fluent Suddenly Closing During Simulation

Skylar · May 12, 2023, 20:05

Apologies in advance for a long post; I wanted to give as much detail as possible. Recently, I've been encountering an issue with Fluent, and I was wondering if I could get some feedback on how to resolve it. The issue is as follows: while running a simulation on Fluent, it will appear to be running fine, and then Fluent will close with no warning or message displayed regarding what happened. I believe this issue is specific to one machine. I have been running the same job on two different machines, and this only happens on a newer PC that I built. On an older machine, the simulation has never crashed and the results look promising for what I'm looking for, so I know the error isn't anything to do with the simulation setup itself.

For reference, the simulation is a turbulent aerodynamics simulation using LES, specifically the Smagorinsky-Lilly SGS model. The machine where I am encountering the issue has an i9-13900K processor and 64 GB of RAM. I am running the simulation in parallel using 24 processes and 1 GPGPU (Nvidia Quadro P4000 to be specific), and I use a little over half the RAM at most during it. I have tried running on both the 2022 R2 and 2023 R1 versions of Fluent and have encountered this issue on both versions; I'll note that the machine that is working fine also uses Fluent 2022 R2. Although I return to see Fluent closed, I did find the following error messages saved:

Error [cortex] [time 5/12/23 13:29:47] Cortex received a fatal signal (SEGMENTATION VIOLATION).

Error [node 0] [time 5/12/23 14:41:6] Abnormal Exit!

Error [node 23] [time 5/11/23 16:31:2] Abnormal Exit!
Node 23 Fatal signal raised sig = Segmentation fault
8535f9a0 CX_Primitive_Error
126eb8f0 log2f
85403750 logical_right_shift
fc14ef50 _C_specific_handler
15293bd0 _chkstk
1520d9c0 RtlFindCharInUnicodeString
15292cc0 KiUserExceptionDispatcher
84ca77e0 Setup_Equation_Grouping
84cb16c0 Make_All_Coarse_Levels
84cb6c40 AMG_Solve
84cd2a70 Fill_AMG_Controls_Scalar
84cd2a70 Fill_AMG_Controls_Scalar
84cd1f50 Solve
84cd8960 LinearSolve
82fd4d90 Solve_P
82fd4d90 Solve_P
82f10d30 alloc_mp_drag_coeff
827d8410 Models_Send_update_solve
82e46630 solver_update
82e42a40 Flow_Iterate
826a8ae0 CX_Enable_Interrupts
853ee840 eval
827b3500 PRF_Command_Start
827b5b80 PRF_Node_repl
827c1270 Delay_Error
85403750 logical_right_shift
138d2690 BaseThreadInitThunk
1524a9d0 RtlUserThreadStart

Error [node 999999] [time 5/12/23 13:29:43] Abnormal Exit!

Based on what I've read elsewhere, it appears that the issue lies in how my one machine handles parallel computing. However, I'm not quite sure how to fix this issue exactly. Has anyone encountered a similar issue? If so, do you know of a way to resolve it?

Thank you in advance for any help!

Skylar · May 15, 2023, 13:04

As an update, it looks like everything is working. Not sure what I did to fix it, but on Fluent 2023 R1, everything is working.

May 12, 2023, 20:05	Fluent Suddenly Closing During Simulation	#1
Skylar New Member Join Date: Nov 2022 Posts: 3 Rep Power: 4	Apologies in advance for a long post; I wanted to give as much detail as possible. Recently, I've been encountering an issue with Fluent, and I was wondering if I could get some feedback on how to resolve it. The issue is as follows: while running a simulation on Fluent, it will appear to be running fine, and then Fluent will close with no warning or message displayed regarding what happened. I believe this issue is specific to one machine. I have been running the same job on two different machines, and this only happens on a newer PC that I built. On an older machine, the simulation has never crashed and the results look promising for what I'm looking for, so I know the error isn't anything to do with the simulation setup itself. For reference, the simulation is a turbulent aerodynamics simulation using LES, specifically the Smagorinsky-Lilly SGS model. The machine where I am encountering the issue has an i9-13900K processor and 64 GB of RAM. I am running the simulation in parallel using 24 processes and 1 GPGPU (Nvidia Quadro P4000 to be specific), and I use a little over half the RAM at most during it. I have tried running on both the 2022 R2 and 2023 R1 versions of Fluent and have encountered this issue on both versions; I'll note that the machine that is working fine also uses Fluent 2022 R2. Although I return to see Fluent closed, I did find the following error messages saved: Error [cortex] [time 5/12/23 13:29:47] Cortex received a fatal signal (SEGMENTATION VIOLATION). Error [node 0] [time 5/12/23 14:41:6] Abnormal Exit! Error [node 23] [time 5/11/23 16:31:2] Abnormal Exit! Node 23 Fatal signal raised sig = Segmentation fault 8535f9a0 CX_Primitive_Error 126eb8f0 log2f 85403750 logical_right_shift fc14ef50 _C_specific_handler 15293bd0 _chkstk 1520d9c0 RtlFindCharInUnicodeString 15292cc0 KiUserExceptionDispatcher 84ca77e0 Setup_Equation_Grouping 84cb16c0 Make_All_Coarse_Levels 84cb6c40 AMG_Solve 84cd2a70 Fill_AMG_Controls_Scalar 84cd2a70 Fill_AMG_Controls_Scalar 84cd1f50 Solve 84cd8960 LinearSolve 82fd4d90 Solve_P 82fd4d90 Solve_P 82f10d30 alloc_mp_drag_coeff 827d8410 Models_Send_update_solve 82e46630 solver_update 82e42a40 Flow_Iterate 826a8ae0 CX_Enable_Interrupts 853ee840 eval 827b3500 PRF_Command_Start 827b5b80 PRF_Node_repl 827c1270 Delay_Error 85403750 logical_right_shift 138d2690 BaseThreadInitThunk 1524a9d0 RtlUserThreadStart Error [node 999999] [time 5/12/23 13:29:43] Abnormal Exit! Based on what I've read elsewhere, it appears that the issue lies in how my one machine handles parallel computing. However, I'm not quite sure how to fix this issue exactly. Has anyone encountered a similar issue? If so, do you know of a way to resolve it? Thank you in advance for any help!

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May 15, 2023, 13:04		#2
Skylar New Member Join Date: Nov 2022 Posts: 3 Rep Power: 4	As an update, it looks like everything is working. Not sure what I did to fix it, but on Fluent 2023 R1, everything is working.