Accessing C_mu within UDF
 

Dear All,

I would like to access the parameter C for use within a Fluent UDF. To this end, could somebody please tell me the variable name such that:

cmu = <???>(cell_index, cell_thread);

Many thanks,
Jack

Well, maybe you can compute from its definition. But I don't know if you can access the viscous turbulence if you're not using Spalart-Allmaras. Maybe this works: (Cmu=turb.visc / density / K^2 * epsilon )

Don't you mean C_MU_L(c,t)?

I have had a better look to the manual and saw that the turbulence eddy viscosity is given by C_MU_T(c,t).

So I correct what I said in previous post, you may compute c_mu as:

cmu=C_MU_T(c,t)/C_R(c,t)/C_K(c,t)/C_K(c,t)*C_D(c,t);

But I wonder... don't you set this parameter as a constant in the turbulence model panel? Why do you need to find it for a specific cell?

CMU access macro
 

CMU is defined as constant in GUI panel so you can directly put its value in the UDF.

I want to modify CMU value as a local variable. I could not find any macro to do this so I used DEFINE_TURBULENT_VISCOSITY() and put my CMU definition there. But the problem seems that this does not suppress the CMU value that is already present in the viscous dialog box of GUI panel.

Can someone help me?

Thanks