Role of dielectric force and solid extraction in electrohydrodynamic flow assisted melting

A numerical study of non-isothermal solid-liquid phase change process in a differentially heated square cavity aided with an electrohydrodynamic (EHD) flow is reported. Melting of a phase change material (PCM) subjected to an electric field with different charge injection strengths is studied. The study aims to numerically demonstrate the solid extraction phenomenon and its role in accelerating the melting process. The EHD flow modifies the flow structure and notably alters the solid–liquid interface morphology. The dielectric force extracts the semi-solid PCM from the melt interface into the liquid bulk with high electric field intensity. The dielectric force causes melting-rate enhancement during the initial stages of melting. While, the later stages of melting are influenced by the combined action of Coulomb and dielectric forces. The role of the Coulomb force is weaker in the weaker charge-injection regimes. Higher electric potential and stronger charge injection generally lead to increased melting rates. Up to 62.12 % decrease in total time taken for melting is achieved within the parameters considered herein.