[lilistar-8216]

Hi, I'm trying to make UDF for changing heat generation rate at the boundary between solid phase and liquid phase. In addition to it, I want to set temperature 300K at solid phase and 550K at liquid phase. My UDF could be compiled and be loaded but if this UDF is loaded at the boundary, I can't change the temperature using patch at initialization setting. (I can initialize without patch.)

This is the error when I try to use patch:
================================================== ============

Node 0: Process 6392: Received signal SIGSEGV.

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


What should I do to use patch setting under loading UDF at the boundary between liquid and solid phases?

[AlexanderZ]

what do you mean under heat generation rate at the boundary
it is applied to volume not boundary.

you should attach your udf here and explain in details each your step before you get the error, if you want to get help

best regards

[lilistar-8216]

Thank you for replying. Sorry I cannot attach all of my UDF but my UDF is like this,

#include "udf.h"
#include "unsteady.h"
#include "mem.h"

DEFINE_PROFILE(heat_profile, thread, i)
{
cell_t c;
Thread *c_thread;
real dt = CURRENT_TIMESTEP;
begin_c_loop(c, c_thread, i)
{
real c_volume = C_VOLUME(c, c_thread);
real dT = C_T_M1(c, c_thread);
.
.
.
F_PROFILE(c, c_thread, i) = (some values* c_volume/dt)*dT;
}
end_c_loop(c, c_thread)
}

I attached this UDF at the wall between fluid phase and liquid phase. I could compile and load this UDF but if I initialize and use patch, that error is occurred.

[AlexanderZ]

#include "udf.h"
#include "unsteady.h"
#include "mem.h"

DEFINE_PROFILE(heat_profile, thread, i)
{
cell_t c;
real dt = CURRENT_TIMESTEP;
begin_c_loop(c, c_thread, i)
{
real c_volume = C_VOLUME(c, thread);
real dT = C_T_M1(c, thread);
.
.
.
F_PROFILE(c, thread, i) = (some values* c_volume/dt)*dT;
}
end_c_loop(c, thread)
}

real dT = C_T_M1(c, thread); return temperature from previous timestep so you should specify it for the first time step

Note that data from C_T_M1 is available only if user-defined scalars are defined. It

best regards

[lilistar-8216]

AlexanderZ,

Thank you for replying. I tried to define the temperature for the first time step but it doesn't work. You told me that I need to define UDS for C_T_M1 but I don't know how to define it. Should I write the UDF for UDS to get C_T_M1 or just set UDS in fluent?

regards