UDF for cell zone condition
 

Hi, I am modeling a system in which the temperature of a large block needs to change with time and with depth (inside the block). A thin pipe (carrying hot liquid) is passing through the block and the temperature of the block around the pipe is affected by that.

So, how do I provide a time-dependent cell zone temperature condition? I cannot use "Fixed value" because the temperature profile inside the block needs to be affected by the pipe. Can I use "Source term" somehow for this?

I think I will be able to make the UDF but how (and where) do I use it? Please help me out.