Analyzing
the heat transfer rate graph, Model A-1 exhibits a higher peak value for
the heat transfer rate, while in the other two regions, Model A-3
displays slightly higher values of heat transfer rate for the same time
frame. This difference may be attributed to the appropriate distribution
of fin lengths.

In summary, considering the results from the plotted data and contour
over time of the melting and solidification processes, the best heat
transfer rate is achieved by Models A-1 and A-3, with Model A-1 having a
slight edge. In overall performance across both processes, Model A-3
demonstrates the optimum heat transfer performance, showcasing
significant improvement in melting and a good performance in
solidification.