The heat absorbed caused by the phase change is represented by (ρ Q).The thermo-physical parameters of this equation are dependent on the material type, so they are varied from one material to the next. Convective and radiation heat transfer on the outer shell: (7) k ∂ T ∂ x = q − h conv T shell − T amb − ɛ σ T shell 4 − T amb 4 where h …