[francescolab]

Could someone, please, help me with this udf code? It's write in the right way but it doesn't work and don't do function in the "else" https://pastebin.com/raw/SMazER3X

  



#include "udf.h"
#include"udf.h"
#include"metric.h"
#include"stdio.h"
#include"math.h"
#include"stdlib.h"
#include"mem.h"

DEFINE_DELTAT(deltat,d)
{
real time_step;
real tx=CURRENT_TIME;
Thread *t,*t0, *t1 =NULL;
cell_t c0, c1 =-1;
face_t f;
Domain *domain;
real x0[ND_ND];
real x1[ND_ND];
int n =0;
real dx =0.0, dy =0.0;
domain = Get_Domain(1);
n =0;
real cent[2];
double centr_x, centr_y;
double vel_x, vel_y;

if ( tx<=1 ) {
 time_step=0.01;
} else {
 DEFINE_ON_DEMAND(calc_distance)
{

thread_loop_f(t,domain)
{
begin_f_loop (f,t)
{
c0 = F_C0(f,t);
t0 = F_C0_THREAD(f,t);
if (BOUNDARY_FACE_THREAD_P(t))
{}
else
{
n+=1;
t1 = F_C1_THREAD(f,t);
c1 = F_C1(f,t);
C_CENTROID(x0,c0,t0);
C_CENTROID(x1,c1,t1);
dx = x1[0]-x0[0];
dy = x1[1]-x0[1];
}
}
end_f_loop (f,t)
}
DEFINE_ADJUST(velocity_profile_face,d)
{
thread_loop_f(t,d)
{
begin_f_loop(f,t)
{
F_CENTROID(cent,f,t);

centr_x = cent[0];
centr_y = cent[1];
vel_x = F_U(f,t);
vel_y = F_U(f,t);

}
end_f_loop(f,t)
}
time_step=MAX (time_step, (dx / vel_x) *0.8);
time_step=MAX (time_step, (dy / vel_y) *0.8);
}
}
}
return time_step;
}

[Svetlana]

The 'else' block starts with a 'DEFINE_ON_DEMAND(calc_distance)', is this intentional?

[francescolab]

Originally Posted by Светлана

The 'else' block starts with a 'DEFINE_ON_DEMAND(calc_distance)', is this intentional?

Yes, but i saw this is wrong, because i read that it's a function that read value at the end of calculations, anyway i would like to understand how to write a function that in the "else" compute max of the division between velocity and cell dimension, and after calculate the time step as time_step = max (dx/velx) * CFL max (0,8 in my case)

[AlexanderZ]

DEFINE_DELTAT DEFINE_ADJUST and DEFINE_ON_DEMAND
are independent macros, you cant use them inside each other

start from this, compile UDF, read logs and fix errors

#include "udf.h"
#include"udf.h"
#include"metric.h"
#include"stdio.h"
#include"math.h"
#include"stdlib.h"
#include"mem.h"

DEFINE_DELTAT(deltat,d)
{
real time_step;
real tx=CURRENT_TIME;
Thread *t,*t0, *t1 =NULL;
cell_t c0, c1 =-1;
face_t f;
real x0[ND_ND];
real x1[ND_ND];
int n =0;
real dx =0.0, dy =0.0;
real cent[2];
double centr_x, centr_y;
double vel_x, vel_y;
n =0;
time_step=0.01;
if ( tx<=1 ) {
 time_step=0.01;
} else {
	thread_loop_f(t,domain)
	{
	begin_f_loop (f,t)
	{
	c0 = F_C0(f,t);
	t0 = F_C0_THREAD(f,t);
	if (BOUNDARY_FACE_THREAD_P(t))
	{}
	else
	{
	n+=1;
	t1 = F_C1_THREAD(f,t);
	c1 = F_C1(f,t);
	C_CENTROID(x0,c0,t0);
	C_CENTROID(x1,c1,t1);
	dx = x1[0]-x0[0];
	dy = x1[1]-x0[1];

	F_CENTROID(cent,f,t);

	centr_x = cent[0];
	centr_y = cent[1];
	vel_x = F_U(f,t);
	vel_y = F_U(f,t);
	time_step=MAX (time_step, (dx / vel_x) *0.8);
	time_step=MAX (time_step, (dy / vel_y) *0.8);
	}
	end_f_loop(f,t)
	}

	}
}
return time_step;
}

time_step=MAX (time_step, (dx / vel_x) *0.8);
time_step=MAX (time_step, (dy / vel_y) *0.8);
are calculated on each face, if you don't want -> fix it

best regards

[francescolab]

Originally Posted by AlexanderZ

DEFINE_DELTAT DEFINE_ADJUST and DEFINE_ON_DEMAND
are independent macros, you cant use them inside each other

start from this, compile UDF, read logs and fix errors

#include "udf.h"
#include"udf.h"
#include"metric.h"
#include"stdio.h"
#include"math.h"
#include"stdlib.h"
#include"mem.h"

DEFINE_DELTAT(deltat,d)
{
real time_step;
real tx=CURRENT_TIME;
Thread *t,*t0, *t1 =NULL;
cell_t c0, c1 =-1;
face_t f;
real x0[ND_ND];
real x1[ND_ND];
int n =0;
real dx =0.0, dy =0.0;
real cent[2];
double centr_x, centr_y;
double vel_x, vel_y;
n =0;
time_step=0.01;
if ( tx<=1 ) {
 time_step=0.01;
} else {
    thread_loop_f(t,domain)
    {
    begin_f_loop (f,t)
    {
    c0 = F_C0(f,t);
    t0 = F_C0_THREAD(f,t);
    if (BOUNDARY_FACE_THREAD_P(t))
    {}
    else
    {
    n+=1;
    t1 = F_C1_THREAD(f,t);
    c1 = F_C1(f,t);
    C_CENTROID(x0,c0,t0);
    C_CENTROID(x1,c1,t1);
    dx = x1[0]-x0[0];
    dy = x1[1]-x0[1];

    F_CENTROID(cent,f,t);

    centr_x = cent[0];
    centr_y = cent[1];
    vel_x = F_U(f,t);
    vel_y = F_U(f,t);
    time_step=MAX (time_step, (dx / vel_x) *0.8);
    time_step=MAX (time_step, (dy / vel_y) *0.8);
    }
    end_f_loop(f,t)
    }

    }
}
return time_step;
}

time_step=MAX (time_step, (dx / vel_x) *0.8);
time_step=MAX (time_step, (dy / vel_y) *0.8);
are calculated on each face, if you don't want -> fix it

best regards

This code is okay and fluent compiled it, anyway it gives me an error of this type now:


https://ibb.co/mBv9WxF

Actual code is this ( i added the definition of domain )

#include "udf.h"
#include"udf.h"
#include"metric.h"
#include"stdio.h"
#include"math.h"
#include"stdlib.h"
#include"mem.h"

DEFINE_DELTAT(deltat,d)
{
real time_step;
real tx=CURRENT_TIME;
Thread *t,*t0, *t1 =NULL;
cell_t c0, c1 =-1;
face_t f;
real x0[ND_ND];
real x1[ND_ND];
int n =0;
real dx =0.0, dy =0.0;
real cent[2];
double centr_x, centr_y;
double vel_x, vel_y;
n =0;
Domain *domain;
domain = Get_Domain(1);
time_step=0.01;
if ( tx<=0 ) {
time_step=0.01;
} else {
thread_loop_f(t,domain)
{
begin_f_loop (f,t)
{
c0 = F_C0(f,t);
t0 = F_C0_THREAD(f,t);
if (BOUNDARY_FACE_THREAD_P(t))
{}
else
{
n+=1;
t1 = F_C1_THREAD(f,t);
c1 = F_C1(f,t);
C_CENTROID(x0,c0,t0);
C_CENTROID(x1,c1,t1);
dx = x1[0]-x0[0];
dy = x1[1]-x0[1];

F_CENTROID(cent,f,t);

centr_x = cent[0];
centr_y = cent[1];
vel_x = F_U(f,t);
vel_y = F_U(f,t);
time_step=MAX (time_step, (dx / vel_x) *0.8);
time_step=MAX (time_step, (dy / vel_y) *0.8);
}
end_f_loop(f,t)
}

}
}
return time_step;
}

[AlexanderZ]

You've made mistake

best regards