[BarmanT]

hello everyone, I am new to fluent UDF, I have followed the manual and everything went smooth up until "function hooks" - did as instructed in the manual but the functions didn't hook.

please need help ASAP!

[BarmanT]

can someone look at my UDF and point on the mistake, because the file compiles but functions won't hook.

#include "udf.h"
#include "flow.h"


DEFINE_ADJUST(inlet_mass_flow,d)
{
int count_m=1;
Thread *t;
face_t f;
thread_loop_f(t,d){
if(N_TIME<=10)
{
if(count_m<=6)
{
begin_f_loop(f,t)
{

F_FLUX(f,t)=(200/3600);
}
end_f_loop(f,t)
}

if(count_m>6 && count_m<=10)
{
begin_f_loop(f,t)
{

F_FLUX(f,t)=0;
}
end_f_loop(f,t)

if(count_m==10)
{count_m=1;}
}
}
else if(N_TIME>10)
{

if(count_m<=6)
{
begin_f_loop(f,t)
{

F_FLUX(f,t)=(50/3600);
}
end_f_loop(f,t)
}

if(count_m>6 && count_m<=10)
{
begin_f_loop(f,t)
{

F_FLUX(f,t)=0;
}
end_f_loop(f,t)

if(count_m==10)
{count_m=1;}
}
}
}
}

DEFINE_ADJUST(inlet_temperature,d)
{
int count_t=1;
Thread *t;
face_t f;
thread_loop_f(t,d){
if(N_TIME<=10)
{
if(count_t<=6)
{
begin_f_loop(f,t)
{

F_T(f,t)=50;
}
end_f_loop(f,t)
}

if(count_t>6 && count_t<=10)
{
begin_f_loop(f,t)
{

F_T(f,t)=50;
}
end_f_loop(f,t)

if(count_t==10)
{count_t=1;}
}
}
else if(N_TIME>10)
{

if(count_t<=6)
{
begin_f_loop(f,t)
{

F_T(f,t)=30;
}
end_f_loop(f,t)
}

if(count_t>6 && count_t<=10)
{
begin_f_loop(f,t)
{

F_T(f,t)=30;
}
end_f_loop(f,t)

if(count_t==10)
{count_t=1;}
}
}
}
}

[AlexanderZ]

when you are clicking LOAD button, the list of available function from UDF is written into console output

if you don't have your function, most likely, you didn't compile UDF successfully

what the name of function which you expect to have? which macro in UDF do you use?

[pakk]

You have a subtle bug in your problem:

F_FLUX(f,t)=(200/3600);

This will default to integer division, which will make the flux zero. You want to make them floats:

F_FLUX(f,t)=(200.0/3600);

Likewise in other places where you divide.

This is not causing the compilation error, to find out what causes the compilation error you should read whatever shows up on your screen directly after you click "build".

[BarmanT]

this is what I get in the TUI after build and load:

# Generating udf_names.c because of makefile udf_n1.obj
udf_names.c
# Linking libudf.dll because of makefile user_nt.udf udf_names.obj udf_n1.obj
Microsoft (R) Incremental Linker Version 14.20.27508.1
Copyright (C) Microsoft Corporation. All rights reserved.

Creating library libudf.lib and object libudf.exp

Done.

LiadArbel-PC: Opening library "G:\avi_folder work\work\NoamSahar_SCE\noam_files\dp0\FLU-2\Fluent\libudf44"...Done.

LiadArbel-PC: Opening library "G:\avi_folder work\work\NoamSahar_SCE\noam_files\dp0\FLU-2\Fluent\libudf44"...
inlet_mass_flow
inlet_temperature
Done.

[BarmanT]

this is what it looks like in the function hooks -

available adjust function[0/0]/// selected adjust function[0/2]
________________________/// inlrt_mass_flow::libudf44
________________________/// inlrt_temperature::libudf44

[BarmanT]

Is anyone familiar with this problem?

[BarmanT]

I found that DEFINE_ADJUST macro won't hook, but DEFINE_PROFILE can be compiled and load properly.

how can I adjust the code above to match DEFINE_PROFILE macro?

[AlexanderZ]

Originally Posted by BarmanT

this is what it looks like in the function hooks -

available adjust function[0/0]/// selected adjust function[0/2]
________________________/// inlrt_mass_flow::libudf44
________________________/// inlrt_temperature::libudf44

this means, that adjusted functions are hooked already, both of them on the right side of menu

the reason, why your boundary conditions are not changing is that you need DEFINE_PROFILE macro to define boundary conditions.
Read Ansys Fluent Customization manual for good examples (or use forum)

[BarmanT]

managed to solve the problem I had here is the final code, if someone has a suggestion for refinement it will be greatly appreciated.

#include "udf.h"

DEFINE_PROFILE(inlet_mass_flow,t,i)
{
printf("Num of Time Step %lld\n", N_TIME);
face_t f;
float res = N_TIME;
float count_m = ((int)((res/96)*100))%100;
printf("\n res %f\n", res);
printf("\n count_m %f\n", count_m);
if(N_TIME<=23040)
{
if(count_m<=25)
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in Mass_Flow 1.1_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=(200.0/3600);
printf("got in Mass_Flow F_PROFILE 1.1_loop count_m %f\n", count_m);
}
end_f_loop(f,t)
}
else
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in Mass_Flow secod IF 1.2_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=0;
printf("got in Mass_Flow F_PROFILE 1.2_loop count_m %f\n", count_m);
}
end_f_loop(f,t)
}
}
else
{
if(count_m<=25)
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in Mass_Flow IF 2_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=(50.0/3600);
printf("got in Mass_Flow F_PROFILE 2.1_loop count_m %f\n", count_m);
}
end_f_loop(f,t)
}
else
{
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=0;
printf("got in Mass_Flow F_PROFILE 2.2_loop count_m %f\n", count_m);
}
end_f_loop(f,t)
}
}
}


DEFINE_PROFILE(inlet_temperature,t,i)
{
face_t f;
float res_t = N_TIME;
float count_t = ((int)((res_t/96)*100))%100;
printf("\n res %f\n",res_t);
if(N_TIME<=23040)
{
if(count_t<=25)
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in temperature 1.1_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=50;
printf("got in temperature F_PROFILE 1.1_loop res %f\n", count_t);
}
end_f_loop(f,t)
}
else
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in temperature secod IF 1.2_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=25;
printf("got in temperature F_PROFILE 1.2_loop res %f\n", count_t);
}
end_f_loop(f,t)
}
}
else
{
if(count_t<=25)
{
printf("Num of Time Step %lld\n", N_TIME);
printf("got in temperature IF 2_loop\n");
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=30;
printf("got in temperature F_PROFILE 2.1_loop res %f\n", count_t);
}
end_f_loop(f,t)
}
else
{
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=25;
printf("got in temperature F_PROFILE 2.2_loop res %f\n", count_t);
}
end_f_loop(f,t)
}
}
}