Most of phase change materials have an obvious density change during solid-liquid phase change, which is along with the volume change of phase change materials, and results in the formation or disappearance of the void cavities based on the encapsulation methods. Void cavities play ignorable roles in the phase-change process, while their influence in the composite porous phase change materials were hardly taken into account in the literatures. In this work, the effect of void cavities on the heat transfer of the porous phase change material has been studied for the first time by a two-dimensional lattice Boltzmann method. The high thermal diffusion coefficient and low conductivity of void cavities show significant influence on not only the temperature distribution but also the energy storage performance. This simulation model gets closer to the real application, which holds great promising for being applied in the guidance on the thermal management system design.
Keywords phase change, metal foam, void cavity, lattice Boltzmann method