CFD Online Discussion Forums - How to use the CFX periodic interface

Quote:

Originally Posted by ghorrocks (Post 676876)

You are running a free surface simulation with surface tension. You will find that to get this to converge you will need amazingly small time steps. Surface tension modelling increases the simulation's sensitivity to time step size. So try smaller time steps. Even better, use the adaptive time steps I recommended before (adaptive time steps works very well for this class of simulations).

long time no see you,I now meet a problem about udf,can you help me?when I interpret it to the fluent,it gives errors "error:E:fluent/volume.c;line 28:parse error." The udf are as follows:

/************************************************** *********************
udfexample.c
UDF for specifying volume profile boundary condition
************************************************** **********************/

#include "udf.h"

DEFINE_PROFILE(inlet_volume, thread, position)
{
real x[ND_ND]; /* this will hold the position vector */
real y, h;
face_t f;
h = -0.0009; /* inlet height in m */
begin_f_loop(f,thread)
{
F_CENTROID(x, f, thread);
y = x[1];
if (y<h)
{
F_PROFILE(f, thread, position) =1;
}
else {
F_PROFILE(f, thread, position) =0;
}
end_f_loop(f, thread)

}