Learning Forum

[z5456415]

Hi,

I am encountering the error "Node 999999 Fatal signal raised: sig = Segmentation fault" at the beginning of my ANSYS Fluent run, which causes Fluent to crash.

My 2D model consists of two airfoils: front and rear. The front airfoil pitches harmonically using a named expression, while the rear airfoil oscillates based on the wake from the front airfoil using a UDF. Additionally, I have another UDF that outputs the pitching angle of the rear airfoil.

During the simulation, I received the following error (copied from the error log). Could anyone please help me in resolving this issue?

Sometimes it shows a "Received Signal SIGSEGV" error as well.

 

Error [node 999999] [time 9/13/24 19:48:16] Abnormal Exit!
Node 999999 Fatal signal raised sig = Segmentation fault
 5e5b1960 CX_Primitive_Error
 edcdb9d0 log2f
 5e61ddf0 logical_right_shift
 cb7de530 _C_specific_handler
 f06f4f20 _chkstk
 f066ddd0 RtlFindCharInUnicodeString
 f06f4010 KiUserExceptionDispatcher
 e2dc0000 Ordinal0
 5e060210 Cell_Functions_List_Cleared
 5e01ad80 Add_ReportDefinition
 5e060210 Cell_Functions_List_Cleared
 5e060210 Cell_Functions_List_Cleared
 5e019420 Evaluate_Udf_ReportDefinitions
 5df61620 Init_Error_Handler
 5e607fd0 eval
 5e607fd0 eval
 5e607fd0 eval
 5e607fd0 eval
 5e60a470 set_cc
 5e60ae50 eval_errprotect
 5e607fd0 eval
 5e607fd0 eval
 5e607fd0 eval
 5e607fd0 eval
 5e60a470 set_cc
 5e60ae50 eval_errprotect
 5e5b2960 CX_Interpret_String
 5cbb6cc0 rpgetvar_errprotect
 5e61ddf0 logical_right_shift
 eeca2560 BaseThreadInitThunk
 f06aaf00 RtlUserThreadStart

[Rob]

Turn off the expression & input UDF. What happens? If it works, turn on the expression based motion. What happens? 

[z5456415]

Hi Rob,

Thank you very much for your message.

I tried without UDFs and only with named expressions. Instead of applying UDFs (input and output) to the rear airfoil, I used a named expression (same as for the front airfoil) as an input for it to pitch. It worked well.

When I tried to debug the issue, I noticed that while compiling the UDFs (using the in-built compiler), those were not updated in the directory ("libudf" and "libudf2" folders). While compiling, sometimes (not always) the console shows a message "Access is denied" to the directory.

Could you please help me with this?

Regards,

Muhammed Sadique

[z5456415]

Another issue I am facing is the "bad termination of one of your application processes" error. I used 4 solver processes to run the simulation. Is this error because of any settings change in Ansys? Also, please note that the files are synced between one drive and the laptop. However the working directory is in onedrive.

[Rob]

Work on the local drive and by all means then back up with OneDrive. We use this configuration at work. Note, with Windows it's sometimes necessary to unload a UDF to then compile again as Windows won't let you modify an open folder: LINUX doesn't suffer from this.