[HyperNova]

there may be macro in your udf that need a model in fluent and you have not activated that! for me in my udf there was C_T(c, t) but i forgot to turn the ENERGY equation!

[nicolas.deraemy]

Hello !

I have a very similar problem that I've been trying to solve for weeks, maybe someone here can help.

The UDF that I created works fine with a "basic" test case, but does not work with another case, which is the one I am working on. The error displayed is:

Node 0: Process 6008: Received signal SIGSEGV.


I have tried to identify the differences between both cases and ran some tests to find out which difference was causing the problem, but nothing I did changed anything.

Basically, my "real" case uses viscous, energy and species transport models, with profiles acting as source terms. I have tried disabeling the species model and getting rid of the source terms, yet the error remains the same.

And for my UDF, I am linking it here. Maybe there's something wrong with it, but it wouldn't be logical, since it is working fine with my test case.

Anyway, hopefully someone here will have an idea of what could be wrong.

Thanks for your help!

[CeesH]

Did you declare the user defined memory locations via define > user-defined > memory.

Quite typically this error means FLUENT is expecting a certain memory location, but it doesn't exist. And in my experience, nearly always forgetting the above is responsible.

[nicolas.deraemy]

Dear CeesH,

Thank you for your answer ! I did declare the user defined memory, for both cases, the test and the real one. It only causes problem on the real case.

[darsonli]

Originally Posted by CeesH

Did you declare the user defined memory locations via define > user-defined > memory.

Quite typically this error means FLUENT is expecting a certain memory location, but it doesn't exist. And in my experience, nearly always forgetting the above is responsible.

Problem solved after changing user-defined-memory location to [2]. Thank you very much!!!

[swethaprakash]

Hey all.

I am using a udf for user defined nongray absorption coefficient for radiation model in fluent and I am getting the same error. I allocated memory as 8 because that's what I says is required in the udf file. Also I am using fluent 16.1 version.

Also I need to use P1 and DO radiation models.

Need help urgently.


this is the error that shows up. Thanks in advance.


MPI Application rank 2 exited before MPI_Finalize() with status -1073741819
The fl process could not be started.

[HyperNova]

hi, first i have a question. do we have fluent ver 16.1 ?
for me that error sometimes happens when my laptop was connected to the internet! i don't know why! goodluck

[swethaprakash]

yes we have 16.1. we have 16.2 also

And I am not sure it is because of the internet. thanks though

[HyperNova]

i read this forum again. i saw that we have talked about some source of errors, have you tried them ?

[Zerzura]

Nice answer worked for me

[xerox]

Hello there!

Currently I am working on an UDF that exports specific cell values as a function of y and z. My flow is a 3d pipe flow with the mean flow in the direction of the z axis. My cell thread is an interior plane normal to the x-direction (like a cut plane in a pipe).

If I want to loop over the interior plane to get the cell temperature of every cell I get the same error as discussed in this thread:

Node 5: Process 6620: Received signal SIGSEGV.

==============================================================================
MPI Application rank 0 exited before MPI_Finalize() with status 2
 The fl process could not be started.

If I try the same loop for the pressure (C_P) my UDF is working fine (by the way C_P is the only working value I can export, neither the velocities nor specific turbulent values or enthalpie etc. is working).

If I try the same loop over another plane, for example the inlet or the outlet instead of the interior, my UDF is working fine.

My UDF looks like the following:

#include "udf.h"

DEFINE_EXECUTE_AT_END(cell_temp)
{


    int i_curr_ts;   
    FILE *f_file;
    char buffer[32];
    
    Domain *d; 
    Thread *t;
    cell_t c;
    float temp;
    real position[ND_ND];   
    float x, y, z;
    
    i_curr_ts = N_TIME;
    d = Get_Domain(1);
              
    snprintf(buffer, sizeof(char) * 32, "ts_%d.txt", i_curr_ts);

    t = Lookup_Thread(d, 4);    /*Inlet: , outlet: 12    */

    begin_c_loop(c, t)
    {
        temp = C_T(c, t);
        C_CENTROID(position, c, t);
        x = position[0];
        y = position[1];
        z = position[2];
        f_file = fopen(buffer, "a");
        fprintf(f_file, "X, Y, Z, %f, %f, %f, %f\n", x, y, z, temp);
        fclose(f_file);
    }
    end_c_loop(c, t)    
}

Are there major issues within the code or why is it not working? Any thoughts about the problem would be highly appreciated.

By the way, I am working with a compiled code on a 64bit Win7 workstation with Ansys 16 (I've already tried different versions, same results). Thank you in advance!

Kind regards!

[Pablo86]

Hello there!

I am facing a similar problem compared to these presented here. Althought my model does not include UDFs, the problem still occurs. I am using v. 16.2 with Windows 12 Server on a remote cluster and work through the workbench.


The log is as follows:

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

Node 999999: Process 17632: Received signal SIGSEGV.

================================================== ============================
MPI Application rank 0 exited before MPI_Finalize() with status 2
The fl process could not be started.

===============Message from the Cortex Process================================

Fatal error in one of the compute processes.

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

Error: Cortex received a fatal signal (unrecognized signal).
Error Object: ()



I have undertaken some trials and errors:
a) whole model loads correctly after the first Fluent run only.

I can calculate the solution, however I am going to use Response Surface Optimization (RSO), so that the Fluent is going to be launched multiple times.

Once the data is saved, another Fluent run results in foregoing error report.

b) If the geometry is changed and new mesh is generated (manually, not through RSO), the Fluent loads correctly for a once, again.

c) As one might expect, running RSO always stucks at Data Loading right after starting Solver stage of progress.

d) I have tried both:
- define > user-defined > user-defined-memory
- define > user-defined > user-defined-node-memory
to set it to the number of processors used, with no effect.

e) The same problem occurs on v. 15.0.7 (which I have used at the first approach)

f) I have no problems with model on my personal computer (Win7 64 bit), it occurs on a cluster only, despite the admin rights I own.


Any idea would be highly appreciated.

Best regards,
Paweł

[nima_nzm]

I had a similar problem. My case is using a dynamic mesh for piston/cylinder modeling. I didn't activate any of the models. I just imported the mesh and did some dynamic mesh preparations and mesh interface things. once I tried to save the case file the message "received signal sigsegv" appeared. As I thought it might be something about the license, I just changed the parallel solution to serial on fluent luncher. Now the problem is gone and I am able to save the .cas as usual.

hope works for you too.

[furqanrk]

Hi everyone !

I hope you are fine. I am using UDF in VOF model in ANSYS FLUENT, although, my VOF model without UDF is running fine. The UDF is written by my friend used it successfully. He has graduated last year after getting the results from same UDF. The UDF was working well on his server. He was using Fluent 6.3 on Linux system. When I am using same case, date and UDF on my laptop the case is not running, although UDF compilation is very fine. I also check it on Linux system too. During or after initialization, Error occurred segmentation fault error. It is very strange that same case and UDF is not working on his office now. Main error occurred when I am hooking ADJUST and EXECUTE-AT-END UDFs. May be there is some problem of writing/calling style is different in Windows and Linux system with 32bit and 64bit. ( this is just my opinion).

I hope you can understand the situation and have a try to fix the problem. I would be highly thankful if you guide me that where is the problem. I can send UDF by email if needed..

Thanks in Advance,
Regards,
M. F. ALi

[BHARAN]

Have you used any udf's in your problem.

[BHARAN]

Try setting up the model without using the udf first and try initializing the solution.
Now interpret the udf and hook it to required options and try initializing the solution.
Segmentation faults can occur because the functions in your udf are trying to access values which have not yet been intialised.

[Sijnhaven]

Dear all,

I am running a VOF mulitphase flow. After a random number of timesteps, I get the error:

Node x: Process xxxx: Received signal SIGSEGV

I have set up the case on ANSYS 18.2 and I am running it on ANSYS 19.0 (due to computational reasons).

For many hours this does not give any problem, but at random moments I get this error. When I then re-read the before-last data, I can continue and Fluent goes beyond the point where it gave the error.

Is it possible that this has something to do with the fact that the solution would be diverging?
How can I prevent Fluent from interrupting the calculation and giving this error?

Kind Regards.

[greenday]

Dear all
Most of the time reloading the mesh will solved the problem. If it not work, try to manually set a new case with the same setup.

[ianziti92]

Hi everyone !

I`m working with this UDF for describing mass transfer, between water and vapour, and the energy exchange. I`ve read the mass transfer (of udf) in the phase interaction window, after I've read the energy source in the cell fluid zone. Now i can`t initialize mi simulation because appear these errors. Can you help me please? thank you



Node 0: Process 7960: Received signal SIGSEGV.


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


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


Node 1: Process 18492: Received signal SIGSEGV.


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


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


Node 2: Process 3692: Received signal SIGSEGV.


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


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


Node 3: Process 12992: Received signal SIGSEGV.


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


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


Node 4: Process 17000: Received signal SIGSEGV.


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


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


Node 5: Process 8368: Received signal SIGSEGV.


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


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


Node 6: Process 1856: Received signal SIGSEGV.


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


999999: mpt_accept: error: accept failed: No such file or directory


999999: mpt_accept: error: accept failed: No such file or directory


999999: mpt_accept: error: accept failed: No such file or directory


999999: mpt_accept: error: accept failed: No such file or directory

[mhoseinm]

Originally Posted by ianziti92

Hi everyone !

I`m working with this UDF for describing mass transfer, between water and vapour, and the energy exchange. I`ve read the mass transfer (of udf) in the phase interaction window, after I've read the energy source in the cell fluid zone. Now i can`t initialize mi simulation because appear these errors. Can you help me please? thank you

Node 0: Process 7960: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 1: Process 18492: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 2: Process 3692: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 3: Process 12992: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 4: Process 17000: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 5: Process 8368: Received signal SIGSEGV.
================================================== ============================
================================================== ============================
Node 6: Process 1856: Received signal SIGSEGV.
================================================== ============================
999999: mpt_accept: error: accept failed: No such file or directory
999999: mpt_accept: error: accept failed: No such file or directory
999999: mpt_accept: error: accept failed: No such file or directory
999999: mpt_accept: error: accept failed: No such file or directory

Hi everyone

i have same problem in simulating a rotor, my UDF task was writing some data relating to the blades in each time step.

the cause of the problem was difference between "Zone ID" of blades in UDF & case file...

you can find Zone ID form B.C. "Task Page" in ANSYS Fluent.

Good luck