Impact of Mechanical Vibration on the Melting of Phase Change Material Applicable to Thermal Energy Storage

This study explores the mechanical vibrational effect on the phase change behavior of a Phase Change Material (PCM). A triplex tube energy storage system is considered in the present computation. The enthalpy porosity technique is adopted to study the melting process of PCM. The governing equations with suitable boundary conditions are solved by the Finite Volume Method (FVM) based commercial software package ANSYS Fluent. A separate User Defined Function (UDF) is written separately for adding mechanical vibration force source term. The simulations are carried out for the control parameter of vibrational amplitude and frequency. The variation of the liquid fraction is evaluated in three cases: without vibration and with vibration at increasing frequency and amplitude. The comparison of liquid fractions demonstrated that mechanical vibration significantly increased the volume of melted liquid. This study also enlightens the quantitative performance evaluation of total energy stored with and without vibration having increasing frequency and amplitude of vibration.