[Deepblack]

Hello everyone,

I am writing a UFD to simulate a dynamic mesh in Fluent.
The function itself works fine. But I want to include a data output, so I can work with the values (e.g. in Matlab). Besides, it's important for me to have a feedback what the function does because I'm still learning C / UDFs and need to understand the language.

Here is my UDF:

//==================================

#include "udf.h"
#include <stdio.h>

DEFINE_CG_MOTION(movement,dt,vel,omega,time,dtime)
{
real t = CURRENT_TIME;
real a,w;
a=1.6;
w=1.5;
NV_S(vel, =, 0.0);
if (!Data_Valid_P())
return;

vel[0]=1;
vel[1] = a * sin(w*t);

printf("x-Vel: %f, y-Vel: %f",vel[0],vel[1]);

// Works till here!
// Data output:

FILE *str;
str = fopen ("Output.txt","w");

if(str==NULL)
{
printf("Error\n");
}

fprintf (str,"x-vel: %f , y-vel: %f \n", vel[0], vel[1]);
fclose (str);
}

//============================

The last part SHOULD create a "Output.txt" file and save all the velocities line by line in it. I hoped that the \n would work but it doesn't.
The file appears and the LAST velocity entry is in line one.

Here is my question: How can I make this UDF write each entry in a new line?

I really hope you guys can help me.