Numerical investigation of the effect of enclosure material and geometrical dimension on the melting behavior of a multilayer phase change material system

In this study, the transient melting behavior of a multilayer phase change material system was numerically investigated. The computational domain consisted of three different phase change materials. RT18 HC, RT22 HC, and SP26 E were placed in the upper, middle, and lower layers, respectively. The numerical analyses were performed using ANSYS Fluent, and the melting process was modeled using the enthalpy-porosity method. The effects of enclosure material and X dimension on the melting performance were comparatively evaluated. For this purpose, four different cases were analyzed by considering aluminum and copper enclosure materials with X = 1 mm and X = 2 mm. A constant temperature of 303 K was applied to the bottom surface, while the remaining external surfaces were assumed to be adiabatic. The results showed that the thermal conductivity of the enclosure material and the X dimension have a significant effect on the melting time. The longest melting time was obtained as 4080 s for the aluminum enclosure with X = 1 mm. The best performance was achieved for the copper enclosure with X = 2 mm, where the total melting time decreased to 2010 s. This configuration provided a 50.74% reduction in melting time compared with the reference case.