We realized the same simulation than previously with the same mesh, the same limit and initial conditions, but, without activating two phases option.
At first, we can notice that we obtained the same profiles of temperature with the two simulations:
Two phases simulation
To be sure that the results were identical, we plot a cut of the middle
of the domain to determinate were the isotherm line was.
Theoretically, this isotherm is not located at the same place if we have only liquid water or if we have solid and liquid water.
Yet, when we compared the simulations, we have found the same results:
Two phases simulation Classical simulation
We looked also at the thermal conductivity during the two phases simulation. Theory foresees that ice and liquid water have not the same one. Nevertheless, the results obtained showed an uniform thermal conductivity.