Add benchmark simulation and test for "heat transfer during the melting of ice around a horizontal, isothermal cylinder"

[agzimmerman]

Try simulating experiments from this paper: https://www.researchgate.net/publication/226804783_Heat_transfer_during_the_melting_of_ice_around_a_horizontal_isothermal_cylinder

This is important for demonstrating...

• a more interesting geometry than the unit square
• validation against another experiment

[agzimmerman]

Your benchmark will probably look a lot like this: https://github.com/geo-fluid-dynamics/sapphire/blob/master/sapphire/benchmarks/melt_octadecane_in_cavity.py

But you shouldn't need the Neumann boundary, and hence also won't modify the run method.

[agzimmerman]

I plan to make a tutorial for melting ice, maybe based on Kai Schueller and Julia Kowalski's experiment, or maybe just a toy problem.