Hi, I am modeling heat transfer in a porous media and get a parse error when I work with the macro C_K_EFF. I get a parse error in that line. If I replace with any other arbitrary macro, say C_K_L or C_MU_EFF or whatever I want it compiles fine. Using V6.1.

Anybody have any ideas why this doesn't work? My UDF is below.

#include "udf.h"

DEFINE_PROPERTY(cell_conductivity, cell, thread) { real k_s; real rho = C_R(cell, thread); real u = C_U(cell, thread); real v = C_V(cell, thread); real mu = C_MU_L(cell, thread); real k_gas = C_K_EFF(cell, thread);

k_s=1.613*(4.62+.0001425*rho/mu*sqrt(u*u+v*v))*k_gas;

return k_s; }

works fine in 6.0.20 here.

If you are feeling adventurous, you could have a browse through udf.h and see how C_K_EFF is defined.

In my #define udf.h C_K_EFF is:

#define C_K_EFF(c,t)(C_K_L(c,t) + C_K_T(c,t))

You already said C_K_L works. What about C_K_T?

Rob

Thanks, actually C_K_T doesn't work either, probably because I'm not even using a turbulence model (I was confused - I didn't want K_EFF, I thought that referred to the effective conductivity of a porous medium).
However I do have another problem, I'm sure this must be something really simple I'm missing, I can't seem to load in more than 2 UDFs at once. If I try to interpret a second UDF, the first one is eliminated from the model. What do I need to do?
Thanks, much appreciated

Well the obvious thing to do is put them all in one file.

To be honest I've never tried to have more than one .c file in a case.

Rob

Ahh, that was the simple thing that I was missing. Seems obvious to me now. Thanks for your help.