okay, i tried the same example as yours on a steady state module after checking the (Share Topology) and update it to be: Edge joints. [It was automatically set to: Automatic]. but unfortunately i didn't get the same distribution as yours don't know whats the problem with me. 

And about "Why i need to solve transient thermal module?"; here is the Ans.: 
Am working on a part in human body that it's temp. increases after specific period of time as result of being supposed to a light source that heats this part. So for the sample sheet model; am assuming that the rectangular sheet is the "Fats" in human body and the circle is a "Tumor".

My Input parameters and boundary conditions are a map for internal heat generation values and temp. for each body.