[Sumin Lee]

Dear Mr. / Ms.,

I made a code for UDF. My purpose was to simulate the opening and closing of the butterfly valve in the pipe in 3D. But The code was not working. Even in fluent, the code is loaded as UDF in fluent.

There is the code below.

#include "udf.h"
#include "math.h"
#include "dynamesh_tools.h"

DEFINE_CG_MOTION(motion, dt, vel, omega, time, dtime)
{
real u = 5.0;
real a = 1.0;
real t1 = u/a;
real t2 = t1 +0.1;
real t3 = t2 +t1;
real angular;

if ( time < t1) {
angular = -0;
omega[1]= angular;
}
else if ( (time > t1) && (time <=t2)) {
angular = -900;
omega[1]= angular;
}
else if ( (time > t2) && (time <=t3)) {
angular = -0;
omega[1]= angular;
}
else {
angular = -0;
omega[1]= angular;
}
NV_S (omega, =, 0.0);
}

I want to that the butterfly valve stays open for 5 seconds, closes in 0.1 seconds, and stays closed for 5 seconds.

[AlexanderZ]

remove last line

NV_S (omega, =, 0.0);

[Sumin Lee]

I'm sorry, the way you told me didn't solve the problem.