At temperature levels above 0
? C, the experimental and simu-
lated results are very close, except that the temperature shifts due
to the density change of water at 4
? C (a convection movement of
the fluid inside the nodule begins, due to this density modification
whichhomogenizes thetemperatureof thewaterasshownin more
details in Fig. 7). At 0
? C and down to ?2 ? C, after the first sensible
heat cooling period of the liquid, the PCM does not directly undergo
the phase transition because of the supercooling phenomenon. As