How to save macro results in the output file?

Peggy

Hi, I encounter the problem of monitor conduction in the natural convection. Does anybody know how to save an macro defined calculation results in the output file(such as C_T_G(c,t)) at every time step as the iteration goes on ? I've thought about using udf,but I'm not sure of the way to to save the output so as to be able to see the output of C_T_G(c,t)as a functiton of time. Any help will be much appreciated. Peggy