[rohinibc]

Hi,

I am unable to get my UDF for setting porosity variation to work out. Here is what my fn.c code looks like.

/*****************************
UDF to specifiy porosity as a function of distance from the wall of the packed bed reactor
************************************/

#include "udf.h"
#define H 0.1
#define dp 0.008


DEFINE_PROFILE(porosity_function,t,i)
{
cell_t c;
real x[ND_ND]; /*This will hold the position vectors*/
real y;
real a1;
real a2=6; /*to specifiy the porosity variation function*/
real eps_inf=0.37;
real eps;

a1 = (1./eps_inf)-1;

begin_c_loop(c,t)
{
C_CENTROID(x,c,t);
y = (H - x[1])/ dp ;
eps = eps_inf*(1. + a1*exp(-1*a2*y));
F_PROFILE(c,t,i) = eps;
}
end_c_loop(c,t)
}

I tried using both F_PROFILE and C_PROFILE inside the code. The code builds and loads alright during compilation. But when I try to use in in the porous zone as function for porosity, it doesn't work. It gives me an error which is :
Error = invalid argument; not a number[1]

Could anybody help me with this?