[ayousefi]

Hi everybody
Here is a short description of my case:
-geometry: 3D, spherical cavity
-unsteady
-two phase flow with free surface (using VOF)
-laminar
The spherical cavity rotates with a time varying angular velocity. This motion is imposed, using a UDF and dynamic mesh technique.
My case works fine with FLUENT 14.0 in both serial and parallel modes. Now I'm forced to use FLUENT 15.0. It gives this error message in serial mode:

Updating mesh at time level N...
Error: received a fatal signal (Segmentation fault).

Error: received a fatal signal (Segmentation fault).
Error Object: #f

and this error message in parallel mode:

Updating mesh at time level N...
================================================== ============================

Node 999999: Process 3800: Received signal SIGSEGV.

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

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

Node 0: Process 3940: Received signal SIGSEGV.

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

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

Node 1: Process 1664: Received signal SIGSEGV.

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

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

Node 2: Process 5876: Received signal SIGSEGV.

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

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

Node 3: Process 5232: Received signal SIGSEGV.

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

And this is my UDF, which I use for dynamic mesh:

PHP Code:

#include "udf.h"
#include "stdio.h"
#include "math.h"
#include "unsteady.h"

#define pi 3.14159265

DEFINE_GRID_MOTION(eye,domain,dt,time,dtime)
{
Thread *tf = DT_THREAD(dt);
face_t f;
Node *v;
real dtheta,a,b;
int n;

SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));
begin_f_loop(f,tf)
{
f_node_loop(f,tf,n)
{
v=F_NODE(f,tf,n);
if (NODE_POS_NEED_UPDATE (v))
{
NODE_POS_UPDATED(v);

    dtheta=((25/9)*pi*(1-pow(tanh((1000*(time-0.2))/30),2)))*dtime;

a=cos(dtheta)*NODE_X(v)-sin(dtheta)*NODE_Y(v);
b=sin(dtheta)*NODE_X(v)+cos(dtheta)*NODE_Y(v);
NODE_X(v)=a;
NODE_Y(v)=b;
}
}
}
end_f_loop(f,tf);
} 


I will appreciate any help
Thanks

[PHThree]

Hi ayousefi,

Have you solved your problem? I met the same error using VOF+dynamic mesh(cutcell). But I did not meet such problem with dynamic layering remeshing with the same UDF.

I guess the error comes from the remeshing method. I appreciate if you can share your experience.

Thank you