Field Function Question. Need help writing it :(((
 

:confused:

So I'm fairly knew to StarCCM and I need to set up my initial wall temperature such that it decreases as it goes along the length. I believe i need to write a field function for this but unfortunately I have zero experience in writing programs/codes and I have no idea how to write field function formula for my problem.

Wont someone be kind enough to help me write a field function?:D

My problem statement is a fluid flowing through a pipe, length say 1m and the temperature of the wall varies through the length.

From L=0 to L=.5 I need my wall temp to be at 150C. From L=.5 to L=.75, the wall temp needs to drop from 150C to 70C, linearly. Similarly, from L=.75 to L=1m, the wall temp needs to drop from 70C to 35C, linearly as well.

Can someone please help me with this??
Many thanks in advance!

Another option is to create an extern Table and read it in Star-ccm+.

With Field Functions it should work also. You get the values of the standard Field Functions through their names, e.g. $$Position[0] gives the i-th coordinate (x in Cartesian). IF-ELSE is like the short form in java, (Expression) ? statement1(if true) : statement2(if false) . You can make the linear drop in an extra Field Function and use it as statement. For further information take a look in the help.