Effects of mechanical vibration on melting characteristics of latent thermal energy storage units using the dynamic mesh method

Phase change materials (PCM) based thermal energy storage technology is an efficient method to overcome the intermittency and instability of energy supply. The heat transfer performance of PCM can be enhanced by the mechanical vibration technique, but the potential mechanisms remain to be revealed. In this study, a dynamic mesh approach was proposed to numerically investigate the effect of mechanical vibrations on the heat transfer performance of PCM. The results indicate that the increase of the vibration frequency leads to the increase of the melting rate, with the vibration frequency increasing from 0 to 3π and 5π, the complete melting time of PCM under vertical vibration can be decreased by 2.21 % and 3.74 %, and complete melting time under horizontal vibration can be decreased by 34.35 %, and 44.39 %, which means that the horizontal vibration exhibits a superior heat transfer enhancement effect. However, it was also found that the energy utilization effect was decreased with the increase of vibration frequency through energy assessment. In addition, the vibration has both promoting and inhibiting effects on the phase transition process, which is related to the melting state and vibration phase. This work provides a novel approach to vibrational simulations and an important guide for practical applications of vibrational heat transfer enhancement.