Learning Forum

[neuvrk]

Hi Everyone,

 

I am working on Ansys Fluent 19.2 , I am getting this error(shown below) when i use UDF for a multiphase simulation, but there is no problem with UDF. Problem here is sometimes its working fine and sometimes not, when i started same simulation freshly, Iterations got  terminated by this error at beginning.

 

 

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

 

Node 0: Process 10964: Received signal SIGSEGV.

 

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

MPI Application rank 0 exited before MPI_Finalize() with status 2

The fl process could not be started.

 

[Rob]

Maybe a network issue? Are there any other messages just before this happens? When you say there is no problem with the UDF, do you mean it compiles OK or that it's worked before? It's possible to have a UDF where the code is correct (in terms of the language) but the maths causes problems as it's calling values that don't exist. 

[Kalyan Goparaju]

Do you have any UDMI's in your UDF? If so, you will need to "initialize" them before you can use them. 

[neuvrk]

`Thanks for reply, Mr.rwoolhou and Mr.Kalyan Goparaju

but, I don't use use any UDMI in UDF, my code is  simple obtaining volume fraction for every timestep using DEFINE_ADJUST macro, here i,j are  cell indices are used in vof array. 

 

#include "udf.h"

Thread *t;

Thread **pt;

face_t f;

cell_t c;

real h = 0.0004;   // grid size

real vof[25][25];

DEFINE_ADJUST(vol_frac,domain)

{

Domain *pdomain = DOMAIN_SUB_DOMAIN(domain,P_PHASE);

mp_thread_loop_c (t,domain,pt)

{

       Thread *tp = pt[P_PHASE];

       begin_c_loop_all(c,t)

     {

     C_CENTROID(X,c,tp);

     i = floor((X[0]-h/2)/h) ;

     j = floor((X[1]-h/2)/h) ;

     vof[j] = C_VOF(c,tp);

     end_c_loop(c,t)

}

}

[Rob]

Does it run without the UDF?  What do you want to do with the volume fraction? 

[neuvrk]

yes rwoolhou, Its running with out UDF and also if i commented out  the below line my simulation is running

vof[j] = C_VOF(c,tp);

I need to get cells with volume fraction 0.5 // which i haven't shown here