[canh.dv@seoultech.ac.kr]

Hi everyone,

I am using UDMI to save the value of temperature at cell 1 as "C_UDMI(c,t,0) = C_T(c,t)".

However, I want to bring this value to a different cell for example cell 2.

How can I do it? I am working in Windows so I cannot use the read/write file.

Thank you.

[AlexanderZ]

your question doesn't make any sense
to use

C_UDMI(c,t,0) = C_T(c,t)

you should define c and t (cell and thread)
the way you define it could give you temperature at 1 specific cell (finite volume) or at the whole domain (in case you are using cell/thread loop)

I am working in Windows so I cannot use the read/write file.

this doesn't make any sense at all, you can use read/write in windows

read ansys fluent customization manual to get more info on cell/thread structure, you may find there examples of udf

[canh.dv@seoultech.ac.kr]

Thank you Alexander for your reply,

I found it in the UDF guide book, they said "DEFINE_RW_FILE cannot be used in UDFs that are executed on Windows systems." https://www.afs.enea.it/project/nept...udf/node29.htm

[canh.dv@seoultech.ac.kr]

I had another question, this is my code:
#include "udf.h"

double AA[2500];

DEFINE_ADJUST(adjust_intensity_to_global_value_2, d)
{
cell_t c;
Thread *t;
face_t f;
real xc[ND_ND];
real xx, yy;
int i,j,m,n, count;

for(i = 0; i<100; i++)
{
for(j = 0; j<25; j++)
{
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
C_CENTROID(xc,c,t);
xx = xc[0];
yy = xc[1];
m = (xx+0.05)/0.001;
n = yy/0.001;

if(m == i && n == j)
{
count = 24*i+j;
AA[count] = 1000*(1-i*0.01);
printf("adjust %d\n", count);
}
}
end_c_loop(c,t)
}
}
}
}

DEFINE_DOM_SOURCE(dom2,c,t,ni,nb,emission,in_scatt ering,abs_coeff,scat_coeff)
{
Domain *d;
face_t f;
real xc[ND_ND];
real xx, yy;
int i,j,m,n,count;
d = Get_Domain(1);
C_CENTROID(xc,c,t);
xx = xc[0];
yy = xc[1];
m = (xx+0.05)/0.001;
n = yy/0.001;
count = 24*m+n;
C_STORAGE_R_XV(c,t,SV_DO_IRRAD,0) = AA[count];
printf("dom2\n");
}

and this is my domain with the 2D mesh of 25 rows and 100 columns, total 2500 cells:


I tried to use a DEFINE_ADJUST to assign the intensity to a global variable matrix AA[24*i+j], and after that, I used a DEFINE_DOM_SOURCE to assign the value from global matrix AA[24*(i-1)+j] to the current intensity.

The problem I face now is when running the simulation, I found that Fluent runs a few cells in "DEFINE_ADJUST" and next run to DEFINE_DOM_SOURCRE and return. Totally 17 times and it is not follow the order of i and j. (I checked by print out "adjust" when run DEFINE_ADJUST and "dom" when run DEFINE_DOM_SOURCE).

As you see in my code, Fluent should run the DEFINE_ADJUST first, assign intensity to 2500 values in AA array first. After that it will run the DEFINE_DOM_SOURCE to take the data from AA array.

Can you guide me to overcome this? I want to finish looping over 2500 cells in DEFINE_ADJUST first and next is run the DEFINE_DOM_SOURCE.

[canh.dv@seoultech.ac.kr]

Originally Posted by canh.dv@seoultech.ac.kr

I had another question, this is my code:
#include "udf.h"

double AA[2500];

DEFINE_ADJUST(adjust_intensity_to_global_value_2, d)
{
cell_t c;
Thread *t;
face_t f;
real xc[ND_ND];
real xx, yy;
int i,j,m,n, count;

for(i = 0; i<100; i++)
{
for(j = 0; j<25; j++)
{
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
C_CENTROID(xc,c,t);
xx = xc[0];
yy = xc[1];
m = (xx+0.05)/0.001;
n = yy/0.001;

if(m == i && n == j)
{
count = 24*i+j;
AA[count] = 1000*(1-i*0.01);
printf("adjust %d\n", count);
}
}
end_c_loop(c,t)
}
}
}
}

DEFINE_DOM_SOURCE(dom2,c,t,ni,nb,emission,in_scatt ering,abs_coeff,scat_coeff)
{
Domain *d;
face_t f;
real xc[ND_ND];
real xx, yy;
int i,j,m,n,count;
d = Get_Domain(1);
C_CENTROID(xc,c,t);
xx = xc[0];
yy = xc[1];
m = (xx+0.05)/0.001;
n = yy/0.001;
count = 24*m+n;
C_STORAGE_R_XV(c,t,SV_DO_IRRAD,0) = AA[count];
printf("dom2\n");
}

and this is my domain with the 2D mesh of 25 rows and 100 columns, total 2500 cells:


I tried to use a DEFINE_ADJUST to assign the intensity to a global variable matrix AA[24*i+j], and after that, I used a DEFINE_DOM_SOURCE to assign the value from global matrix AA[24*(i-1)+j] to the current intensity.

The problem I face now is when running the simulation, I found that Fluent runs a few cells in "DEFINE_ADJUST" and next run to DEFINE_DOM_SOURCRE and return. Totally 17 times and it is not follow the order of i and j. (I checked by print out "adjust" when run DEFINE_ADJUST and "dom" when run DEFINE_DOM_SOURCE).

As you see in my code, Fluent should run the DEFINE_ADJUST first, assign intensity to 2500 values in AA array first. After that it will run the DEFINE_DOM_SOURCE to take the data from AA array.

Can you guide me to overcome this? I want to finish looping over 2500 cells in DEFINE_ADJUST first and next is run the DEFINE_DOM_SOURCE.

https://prnt.sc/u7YLPk_estnB[/IMG]