[teethfish]

Hi, I want to modify the viscosity in K-W SST model in Fluent 13.0. But I met a problem that my UDF cannot initiate and it shows that:
Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
1. Note exact events leading to error.
2. Save case/data under new name.
3. Exit program and restart to continue.
4. Report error to your distributor.
Error Object: #f

I have tried initialise without using "compute from" ....but the error was still there, I pasted my UDF here, if anone can help me with that?

#include "udf.h"

DEFINE_TURBULENT_VISCOSITY(user_mu_t,c,t)
{
real mu_t;
real a;
real rho;
real k;
real d;

a=(C_R(c,t)-0.5542)/997.6458;
rho = 0.5542+a*a*997.6458;

k = C_K(c,t);
d = C_D(c,t);
mu_t = M_keCmu*rho*k*k/d;
return mu_t;
}