I am modelling temperature distribution of a circular cylindrical rod with a plate. The model is very much similar to (https://au.mathworks.com/help/pde/ug/heat-distribution-in-a-circular-cylindrical-rod.html) model. In my model, I am using heat flux boundary condition at the edge 2 (interface of rod and plate) which is varying with time. I have set 298 K as atmospheric temperature and 910 K as initial temperature. It is expected that heat flux will be zero when the edge temperature will reach at atmospheric temperature. I have set the boundary condition as given in the following code. The results do not seem correct because the edge temperature reaches steady state at time t=1s for all initial temperatures (T_0 = 510K and 910K).