PCM (Phase Change Material) can be considered as an attractive option for thermal energy storage due to its high energy density and isothermal process. The understanding of melting characteristics of a PCM is very much necessary for the effective storage/dissipation of heat. One of the important parameters which influences the melting behaviour is mushy zone constant. The present study aims to address the influence of mushy zone constant on the melting characteristics of a PCM by performing 2-D transient numerical simulations in a rectangular cavity. The PCM considered for the study is gallium. The investigation has been carried out using a commercial CFD code ANSYS Fluent 16.0.

The mushy zone constant is varied from 10³ to 10⁸, and its influence on the melt fraction and the amount of heat stored has been studied. Results are presented in terms of melt fraction and stream function contours, melt fraction and heat stored. Based on the study, it is observed that the mushy zone constant significantly influence the thermohydraulics of a PCM.