##### Posted by: moloy_kb

«**on:**June 27, 2012, 11:23:50 AM »

Dear all,

I am simulating the problem of blood flow through an artery in 2D considering laminar flow. For this I am using the Walburn and Scneck model to define the blood viscosity using the equation:

mu_lam=K*(strain)^(n-1), where K=14.67*10^(-3) and n=0.7755. In order to define the viscosity I am using the following UDF:

#include "udf.h"

DEFINE_PROPERTY(cell_viscosity_power_law,c,t)

{

double mu_lam;

double strain;

double muinf = 14.67e-3;

double n = .7755;

strain = pow(C_DUDX(c, t),2)+ pow(C_DVDY(c, t),2)+

2*pow(C_DUDY(c, t)+ C_DVDX(c, t),2)+

2*pow(C_DUDZ(c, t),2)+

2*pow(C_DVDZ(c, t),2);

strain = pow(strain, 0.5);

strain =fabs(strain);

mu_lam=muinf*pow(strain,n-1);

return mu_lam;

}

But, once I try to solve it the solver gives the error: Divergence detected in the AMG solver.

Please help me...

I am simulating the problem of blood flow through an artery in 2D considering laminar flow. For this I am using the Walburn and Scneck model to define the blood viscosity using the equation:

mu_lam=K*(strain)^(n-1), where K=14.67*10^(-3) and n=0.7755. In order to define the viscosity I am using the following UDF:

#include "udf.h"

DEFINE_PROPERTY(cell_viscosity_power_law,c,t)

{

double mu_lam;

double strain;

double muinf = 14.67e-3;

double n = .7755;

strain = pow(C_DUDX(c, t),2)+ pow(C_DVDY(c, t),2)+

2*pow(C_DUDY(c, t)+ C_DVDX(c, t),2)+

2*pow(C_DUDZ(c, t),2)+

2*pow(C_DVDZ(c, t),2);

strain = pow(strain, 0.5);

strain =fabs(strain);

mu_lam=muinf*pow(strain,n-1);

return mu_lam;

}

But, once I try to solve it the solver gives the error: Divergence detected in the AMG solver.

Please help me...