Hi,

Can anyone please post or direct me towards an example udf for dynamic mesh motion Thanks, Avant

Hi

There is an example in fluent tutorial, which uses dynamic mesh. Go through its udf.

Regards,

Manoj

Following udf calculates force acting on a regid body and sets its x-component of velocity. At the end of every time step, the udf is used and the mesh is updated.

#include "udf.h"

static real v_prev = 0.0;

DEFINE_CG_MOTION(block,dt,vel,omega,time,dtime)

{ Thread *t;

face_t f;

real NV_VEC(A);

real force, dv;

/* reset velocities */

NV_S(vel, =, 0.0);

NV_S(omega, =, 0.0);

if (!Data_Valid_P())

return;

/* get the thread pointer for which this motion is defined */

t = DT_THREAD(dt);

/* compute pressure force on body by looping through all faces */

force = 0.0;

begin_f_loop(f,t)

{

F_AREA(A,f,t);

force += F_P(f,t) * NV_MAG(A);

}

end_f_loop(f,t)

/* compute change in velocity, i.e., dv = F * dt / mass

velocity update using explicit Euler formula */

dv = dtime * force / 50.0;

v_prev += dv;

Message ("time = %f, x_vel = %f, force = %f\n", time, v_prev, force);

/* set x-component of velocity */

vel[0] = v_prev;

}