[Tushar_Telmasre]

At the free surface in my model i want to incorporate the convective and radiative boundary conditions.

I tried to use the define profile macro at the boundary.

my udf is as follows,

#include "udf.h"

DEFINE_PROFILE(wallheatgenerate,thread,i)
{

face_t f;
real source = 500*(C_T(f,thread)-300) + 0.09*(pow(C_T(f,thread),4)-pow(300,4)));

begin_f_loop(f,thread)
F_PROFILE(f,thread,i) = source;
end_f_loop(f,thread)
}

here,
real source = h*(T_Wall-T_Ambient); + emissivity*(pow(T_wall,4)-pow(T_Ambient,4)));

i do not know whether it is right. I am getting convergence issues.
i think i have not incorporated cell area into it.(the actual formula being h*A*(T_wall-T_ambient) )

can any one please suggest. I am struggling with this relatively simple problem for a long time.