Mohammad Nazififard - Department of Energy Systems Engineering, School of Mechanical Engineering, University of Kashan;
Mohammad Sadegh Badri - Department of Energy Systems Engineering, School of Mechanical Engineering, University of Kashan;
Shayan Najafzadeh - Department of Energy Systems Engineering, School of Mechanical Engineering, University of Kashan;
Hamed Jowkar - Department of Energy Systems Engineering, School of Mechanical Engineering, University of Kashan;

This paper, numerically and experimentally study and visualize the solidification process of phase change material (PCM) inside a sphere. The sphere volumes containing PCM are 250, 500 and 1000 ml. The atnbient temperature is 28C. The problem is considered two- dimensional in geometry and transient in time. The computational fluid dynamics model here adopted consists of mass. momentum, energy and volume fraction equations. The results have been validated by comparison with temperature measurements of commercial paraffin wax as PCM during solidification. The solidification process is investigated numerically applying an axisymmetric computational fluid dynamics (CF D) model of solidification processes of the encapsulated PCM inside a sphere using ANSYS Fluent 18.2 software. Experimental validation showed the CFD simulation predicts a slower rate of solidification than the experiment. The findings of this CFD study have a number of important implications for the design and operation of the phase change heat storage unit with sphere containers.

phase change material, computational fluid dynamics, visualization, solidification