[rahilvalani]

Hi there,

I am trying to simulate vortex induced vibrations using Ansys fluent at Re=100 using the following udf for 6DOF solver:

#include "udf.h"
DEFINE_SDOF_PROPERTIES(viv, prop, dt, time, dtime)
{
real cg;
real k = 1.578;
cg = DT_CG(dt)[1];
prop[SDOF_MASS] = 1;
prop[SDOF_LOAD_F_Y] = -k*cg;
prop[SDOF_ZERO_TRANS_X] = TRUE;
prop[SDOF_ZERO_ROT_X] = TRUE;
prop[SDOF_ZERO_ROT_Y] = TRUE;
}

When I simulate this, it gives me very large lift coefficient(~100-200) and the cylinder also oscillates very rapidly. Can some please help?