[Kuljeet]

hi
i am using this UDF to write DO intensity into a file. the case is square cavity with wall at 0K and CO2 at 1000K inside). When i am writing for individual face, i am getting right values its not happening for the whole wall, i am using a coarse grid just to check that. can anyone look into it. I think the problem is with parallel architecture i.e., have 1 host and 1 node process.

-K

Link for case file, UDF and generated files for both case.
"https://drive.google.com/file/d/1dItCD05Y9APaoA-AWt6RsqSvFhg5YUMd/view?usp=share_link"

[AlexanderZ]

share your code, explain problems

[Kuljeet]

#include "udf.h"
# define FLUID_ID 2
DEFINE_ON_DEMAND(intensity_to_file)
{
/* Different variables are needed on different nodes */
#if !RP_HOST
Domain *domain=Get_Domain(1);
Thread *thread;
face_t f;
cell_t c;
int k;
#else
int i;
#endif
#if !RP_NODE
FILE *fp = NULL;
char filename[]="intensity12.txt";
#endif
int size; /* data passing variables */
real *array;
int pe;
#if !RP_HOST
thread=Lookup_Thread(domain,8); // bottom wall id =8;
#endif
#if !RP_NODE
if ((fp = fopen(filename, "w"))==NULL)
Message("\n Warning: Unable to open %s for writing\n",filename);
else
Message("\nWriting intensity to %s...",filename);
#endif
/* UDF Now does 2 different things depending on NODE or HOST */
#if RP_NODE
/* Each Node loads up its data passing array */
size=THREAD_N_ELEMENTS_INT(thread)*4*1*1;
array = (real *)malloc(size * sizeof(real));

//for (int l=0;l<10;l++)/////////////////////////////////writing
//{
begin_f_loop_int(f,thread) //f is from 0 to 9

for(k=0;k<4;k++) ////////////k is no of angualr discritised grid points = phi*theta*4(2D case)
{
array[k*(l+1)]= C_DO_I(l,thread,k);
Message("%f\n",array[k*(l+1)]);
//printf("%lf",array[k]);
//array[k]= F_DO_I(9,thread,k);
}

end_f_loop_int(f,thread)

/* Set pe to destination node */
/* If on node_0 send data to host */
/* Else send to node_0 because */
/* compute nodes connect to node_0 & node_0 to host */

pe = (I_AM_NODE_ZERO_P) ? node_host : node_zero;
PRF_CSEND_INT(pe, &size, 1, myid);
PRF_CSEND_REAL(pe, array, size, myid);
free(array);/* free array on nodes after data sent */
/* node_0 now collect data sent by other compute nodes */
/* and sends it straight on to the host */
if (I_AM_NODE_ZERO_P)
compute_node_loop_not_zero (pe)
{
PRF_CRECV_INT(pe, &size, 1, pe);
array = (real *)malloc(size * sizeof(real));
PRF_CRECV_REAL(pe, array, size, pe);
PRF_CSEND_INT(node_host, &size, 1, myid);
PRF_CSEND_REAL(node_host, array, size, myid);
free((char *)array);
}
#endif /* RP_NODE */
#if RP_HOST
compute_node_loop (pe) /* only acts as a counter in this loop */
{
/* Receive data sent by each node and write it out to the file */
PRF_CRECV_INT(node_zero, &size, 1, node_zero);
array = (real *)malloc(size * sizeof(real));
PRF_CRECV_REAL(node_zero, array, size, node_zero);

//for (i=0; i<8; i++)
for (i=0; i<size; i++)
fprintf(fp, "%g\n", array[i]);
free(array);
}
#endif /* RP_HOST */
#if !RP_NODE
fclose(fp);
Message("Done\n");
#endif
}

[AlexanderZ]

try this code, compile

#include "udf.h"
# define FLUID_ID 2

DEFINE_ON_DEMAND(intensity_to_file)
{
/* Different variables are needed on different nodes */
Domain *domain;
Thread *thread;
face_t f;
cell_t c;
int i,k;
FILE *fp = NULL;
char filename[]="intensity12.txt";
int size; /* data passing variables */
real *array;
domain=Get_Domain(1);
thread=Lookup_Thread(domain,8); // bottom wall id =8;
#if !RP_NODE
if ((fp = fopen(filename, "w"))==NULL)
Message("\n Warning: Unable to open %s for writing\n",filename);
else
Message("\nWriting intensity to %s...",filename);
#endif

#if RP_NODE
size=THREAD_N_ELEMENTS_INT(thread)*4*1*1;
array = (real *)malloc(size * sizeof(real));

begin_f_loop_int(f,thread) /*f is from 0 to 9*/
{
	for(k=0;k<4;k++) /*k is no of angualr discritised grid points = phi*theta*4(2D case)*/
	{
	array[k*(f+1)]= C_DO_I(f,thread,k);
	Message0("%f\n",array[k*(f+1)]);
	}
}
end_f_loop_int(f,thread)
#endif
node_to_host_int_1(size);
node_to_host_real(array,size);

#if !RP_NODE
for (i=0; i<size; i++)
fprintf(fp, "%g\n", array[i]);
free(array);
fclose(fp);
#endif
Message0("Done\n");
}

[Kuljeet]

Thanks for replying, but this code is not compiling. It is showing error mentioned below. I think we cant write to a file without using parallel architect.

ERROR: The UDF library you are trying to load (libudf) is not compiled for parallel use on the current platform (win64).
The system cannot find the file specified

-K

[AlexanderZ]

press build, not load

[Kuljeet]

But how will i execute it. If i just load code, it is not showing in "execute on demand". So its not writing into anything.

[AlexanderZ]

google "how to compile code in fluent"