[Josyula]

Hi,

I have written an UDF for implementing a non-newtonian viscosity model for blood. This is the UDF:-

#include "udf.h"
#define mu_plasma 0.0012
#define H 0.47
DEFINE_PROPERTY(cumul_viscosity,c,t)
{
real mu_blood,beta,gamma,a,b,d;
gamma = C_STRAIN_RATE_MAG(c,t);
beta = 1+(6.0/pow(gamma,0.75));
a = beta*(1-H);
b = (4.1*H)/(1.64-H);
d = mu_plasma*a;
mu_blood = pow(d,b);
return mu_blood;
}

I am getting 'Divergence in AMG solver - x momentum' error.

I tried reducing the time step size and URF. Nothing seems to work.

Any suggestions on how to resolve this?

Thank you.