[Camiwu]

Hi, I got this full error when trying to run this execute_at_end code for write and calculate heat flux on a steel wall: "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"

this is the code:

#include "udf.h"
#include "stdio.h"

#define UDM_HEAT_FLUX 0

DEFINE_EXECUTE_AT_END(compute_and_write_heat_flux)
{

Domain* domain = Get_Domain(5);
Thread* t;
face_t f;
FILE* fp;

fp = fopen("Heat_flux_compute_data.csv", "w");

if (fp == NULL)
{
Message("Error opening file Heat_flux_compute_data.csv\n");
return;
}

fprintf(fp, "Face ID, Heat Flux\n");

/*check #if !RP_HOST and #if !NODE for parallelization*/

/* Iterate over all face threads */
thread_loop_f(t, domain)
{
/* Loop over all faces in the thread */
begin_f_loop(f, t)
{
if (PRINCIPAL_FACE_P(f, t)) /* Tests if the face is the principal face (compiled udf) */
{
real heat_flux = 0.0;
real k;
real grad_T[ND_ND];
real temp;
real A[ND_ND];

F_AREA(A, f, t);

/* If face lies at domain boundary, use face values; */
/* If face lies IN the domain, use average of adjacent cells. */
if (BOUNDARY_FACE_THREAD_P(t))
{
/* Get thermal conductivity */
k = F_K_L(f, t);

/* Depending on its BC, temperature may not be set on face thread */
if (NNULLP(THREAD_STORAGE(t, SV_TEMPERATURE)))
{
temp = F_T(f, t); /* Set temp to face value if available */
}
else
{
cell_t c0 = F_C0(f, t);
Thread* t0 = THREAD_T0(t);
temp = C_T(c0, t0); /* else, set temp to cell value */
}

F_T_G(f, t, grad_T); /* Get temperature gradient at the face */
heat_flux = -k * grad_T[1]; /* Calculate heat flux in y-direction with Fourier's law */
}
else
{
/* For internal faces, use average of adjacent cells */
cell_t c0 = F_C0(f, t);
cell_t c1 = F_C1(f, t);
Thread* t0 = THREAD_T0(t);
Thread* t1 = THREAD_T1(t);

real k0 = C_K_L(c0, t0);
real k1 = C_K_L(c1, t1);
real k_avg = 0.5 * (k0 + k1);

real grad_T0[ND_ND], grad_T1[ND_ND];
C_T_G(c0, t0, grad_T0);
C_T_G(c1, t1, grad_T1);

real grad_T_avg[ND_ND];
NV_VS(grad_T_avg, =, 0.5, *, grad_T0, +, 0.5, *, grad_T1);

heat_flux = -k_avg * grad_T_avg[1]; /* Calculate heat flux in y direction [1] */
}

C_UDMI(F_C0(f, t), t, UDM_HEAT_FLUX) = heat_flux; /* Store the heat flux in UDM */

fprintf(fp, "%d, %g\n", f, heat_flux); /* Write face ID and heat flux to file */
}
}
end_f_loop(f, t)
}

/*#endif*/

fclose(fp);
Message("Heat flux data written to Heat_flux_compute_data.csv\n");

}

I am opening Fluent via the VS command for windows x64.