[Topspin]

I want to export heat flux from a panel in a flat plate flow where the temperature of the plate varies with time.

The ASCII automatic data export tool in Fluent is nice, but it creates a new file for every timestep.

Is there a way to write a UDF to export the data from every timestep into a single file in this manner?:

time1|temperature1|vector1 of heat flux from cell center
time2|temperature2|vector2 of heat flux from cell center
...
time100|temperature100|vector100 of heat flux from cell center

If there is could I be pointed to a similar example?

[macfly]

Hi,

Try this udf, it works in serial, you will have to modify the code if you work in parallel:

#include "udf.h"
DEFINE_EXECUTE_AT_END(execute_at_end)
{
FILE *data;
real coord[ND_ND];
real temperature;
real time = CURRENT_TIME;
real timestep = N_TIME;
Domain *d;
Thread *t;
cell_t c;
d = Get_Domain(1);

if (timestep == 1)
     {
     data = fopen("data.txt", "w");
     fprintf(data, "time x y z temperature\n");
     }
else
     data = fopen("data.txt", "a");

//fprintf(data, "current time is %g s\n", time);

thread_loop_c(t,d)
     {
     begin_c_loop(c,t)
          {
          C_CENTROID(coord,c,t);
          temperature = C_T(c,t);
          fprintf(data, "%g %g %g %g %f\n", time, coord[0], coord[1], coord[2], temperature);
          }
     end_c_loop(c,t)
     }
fclose(data);
}

[Topspin]

Thank you I will try it very soon! Right now I've been using Matlab to automate the process of pulling data from each timestep file, but this is a much more elegant solution.