[Leb]

Hi,

I'm trying to use DEFINE_PROFILE in a transient case and the problem I encounter is that my velocity component data file (which has data for *all* time steps, not just a single one) is read every iteration as opposed to time step, so I was wondering if there is an equivalent to NODE_POS_NEED_UPDATE used in DEFINE_GRID_MOTION? Or is there an alternative way?

#include "udf.h"



DEFINE_PROFILE(v_component, thread, position)
{
face_t f;
real x[ND_ND];
real y;
double v;
real t = CURRENT_TIME;
FILE *v_values;
v_values = fopen("v_intp.txt","r");

begin_f_loop(f, thread)
{
F_CENTROID(x,f,thread);
y = x[1];

fscanf(v_values, "%lf\n", &v);
Message("The v is %lf\n", v);
Message("The x is %f\n", x[0]);
F_PROFILE(f, thread, position)  = v;
}
end_f_loop(f, thread)
}

In other words, I need to read next profile data lines every time step, not iteration...

[gearboy]

Originally Posted by Leb

Hi,

I'm trying to use DEFINE_PROFILE in a transient case and the problem I encounter is that my velocity component data file (which has data for *all* time steps, not just a single one) is read every iteration as opposed to time step, so I was wondering if there is an equivalent to NODE_POS_NEED_UPDATE used in DEFINE_GRID_MOTION? Or is there an alternative way?

#include "udf.h"



DEFINE_PROFILE(v_component, thread, position)
{
face_t f;
real x[ND_ND];
real y;
double v;
real t = CURRENT_TIME;
FILE *v_values;
v_values = fopen("v_intp.txt","r");

begin_f_loop(f, thread)
{
F_CENTROID(x,f,thread);
y = x[1];

fscanf(v_values, "%lf\n", &v);
Message("The v is %lf\n", v);
Message("The x is %f\n", x[0]);
F_PROFILE(f, thread, position)  = v;
}
end_f_loop(f, thread)
}

In other words, I need to read next profile data lines every time step, not iteration...

I believe Fluent will run DEFINE_PROFILE every iteration. So,just put your reading/close file function in it. The profile will be updated every iteration.

[Leb]

Thanks for your reply, but as I mentioned, I do *not* want to update the profile every iteration, but every time step.

I was hoping that I could use something like this:

if (t = 0.000000)
	u_values = fopen("u_comp_0.txt","r");
else
	{
	u_values = fopen(strcat(strcat(foo,str),bar ),"r");
	}

where

 strcat(strcat(foo,str),bar )

is simply the division of CURRENT_TIME by my time_step (which is fixed), but I got a fatal signal (ACCESS_VIOLATION) for some reason...