[dinhanh]

Hi Fluent Experts,

I am trying to write a UDF for the turbulent viscosity based on the Realizable k-e model (See the Figure below).
The UDF code is for 2D simulation, and I had trouble defining the term W. The code got an error when it compiled.

Is the definition of W correct? Thank you very much for your help.

The UDF code is:

#include "udf.h"

DEFINE_PROPERTY(tur_vis,c,t)
{
real mu_tur;
real Sii, Sij, Sjj, Wij, Wijr;
real SMU, WAS, PHI, USTAR;
real AS;
real CMU, y, a1, a2, a3, a4, a5, a6;
real betas=0.09;
real A0=4.04;
real wr=11.7 /***rotational speed***/

/*** Cal Sij and Wij
Sii=0.5*(C_DUDX(c,t)+C_DUDX(c,t));
Sij=0.5*(C_DUDY(c,t)+C_DVDX(c,t));
Sjj=0.5*(C_DVDY(c,t)+C_DVDY(c,t));

Wij=0.5*(C_DUDY(c,t)-C_DVDX(c,t));

/*** Cal vorticity with rotational rate ***/

Wijr=Wij-wr*C_D(c,t);

/*** Cal U* ***/

USTAR=sqrt(Sii*Sii+2*Sij*Sij+Sjj*Sjj+Wijr*Wijr);

/*** Cal Phi ***/

SMU=sqrt(Sii*Sii+2*Sij*Sij+Sjj*Sjj);
WAS=(2*Sij+Sii+Sjj)/pow(SMU,3);
PHI=1/3*pow(cos(sqrt(6)*WAS),-1);

/*** Cal As ***/

AS = sqrt(6)*cos(PHI);

/*** Cal CMU ***/

CMU=1/(A0+AS*USTAR/betas/C_O(c,t));

mu_tur=C_R(c,t)*pow(C_K(c,t),2)/C_D(c,t)*CMU

return mu_tur;
}