Gradation of temperature in wall boundary
 

Hello:)

I have a wall boundary in my model with zero thickness. I used a fixed temperature but now i wanna change it having a gradient temperature from 200 to 500 oC along the wall.
Is user defined functions the only way to do it? Is there any other way to set temperature gradation in a single wall phase ?
If i seperated this face to a few little and setting a raising temperature from the one to the other end of the initial face??

Im waiting for help:)

Thank you in advance

Panos;)

I just wanted you to recommend me some udf files that describe a gradient boundary, velocity, pressure or temperature.
The equation that describes my case is T(x)= a + b*X
Can somebody please tell me where i can find related UDFs?
Thanks again