CFD Online Discussion Forums - modelling heat flux in udf

I have problem with defining moving heat flux in udf. Heat flux is limited by circle and rest of the face transfering heat by convection.

I tried many times to modify this code but I even wasn't able to have stable heat flux circle on a face with desired parameters.

Mesh geometry is a cube.

I'll be really gratefull to anyone who help me with this code.

Code:

#include "udf.h"



DEFINE_PROFILE(laser,thread,i)



{

  real q = 1000;

  real t = CURRENT_TIME;

  real x[ND_ND]; 

  real qO;

  real xO = 5;

  real xOt;

  real z = 0;     

  real v = 0.003;

  real r = 0.001; 

  real alfa = 20;

  real TO = 290; 

  real Tp = 280; 

  face_t f;

  

  xOt = xO + v*t; 

  qO = alfa*(TO-Tp);  





 

  



      begin_f_loop(f,thread)

{

  

       F_CENTROID(x,f,thread);

        

       if ( ((x[0]-xOt)*(x[0]-xOt) + (x[1]-z)*(x[1]-z) ) <= r*r )

    

       F_PROFILE(f,thread,i) = q;



       else  



       F_PROFILE(f,thread,i) = qO;

}

       end_f_loop(f,thread)



}